UNDERSTANDING THE HUMAN BODY
NOTES

Anatomical Position - Posterior = Back
Anterior = Front
Dorsal = Back
Ventral = Front
Medial = Middle
Lateral = Side
Superior = Above
Inferior = Below
Proximal = Near point of attachment / Beginning
Distal = Away from point of attachment / end
Cephalic = Head
Caudal = Tail

Anatomical Guides – Using a known anatomical structure or region identifying an underlying or adjacent structure.

Linear Guide – Drawing a real or imaginary line to locate an anatomical structure.

Anatomical Limits – Proximal and distal aspects of an Anatomical structure.

Planes - imaginary divisions of the human body. Sagittal – Cut the body in half from Left Right
Midsagittal – Equal part left right
Parasagittal – Non-equal left right parts.
Coronal – Dividing body from front back
Transverse – Divides the body into superior and inferior

Body Cavities -

The human body consists of the following body cavities:
Dorsal body cavity
Cranial cavity- enclosed by the Skull and contains the brain, eyes, and ears.
Spinal canal - enclosed by the spine and contains the spinal cord.
Ventral body cavity
Thoracic cavity enclosed by the ribcage and contains the lungs and heart.
Abdominopelvic cavity
Abdominal cavity, enclosed by the ribcage and pelvis and contains the Kidneys, ureters, stomach, intestines, liver, gallbladder, and pancreas Pelvic cavity, enclosed by the pelvis and contains bladder, anus and reproductive system.

Pelvic Region and Quadrants

Pelvic Regions Abdominal Quadrants

Division of anatomical study
Neurology
Eyes, ears, and throat
Internal
Cystology
Histology
Pathology
Cytology

Cytology – the study of cells. Cytology is that branch of life science, which deals with the study of cells in terms of structure, function and chemistry.

Cells are the basis of life.

Organelles are made up of molecules (macromolecules)

CARBOHYDRATES:
Includes: Sugars, starches, cellulose & glycogen
Made of Carbon (C), Hydrogen (H), and Oxygen (O)
Following ratio of elements CnH2nOn
Sugars: Provide & store energy for cells
Simple sugars include Glucose & Fructose since these are made of only 1 Carbohydrate molecule they are known as Monosaccharides.

Monosaccharides can be linked together through the process of Dehydration Synthesis
Water is removed from 2 monocaccharides - resulting in a covalent bond between the 2 molecules
Sucrose (table sugar) is made of 2 sugars linked together and these are called Disaccharides
Often referred to as transport saccharides
Require some digestion to be used by cells
Polysaccharides
Polysaccharides are glycosides between sugars. The name given to the polysaccharide is dependent on the size of the molecule...
1 sugar unit: monosaccharide
2 sugar units: disaccharide
3 sugar units: trisaccharide
3-several sugar units: oligosaccharide
100+ sugar units: polysaccharide

Starches are many monosaccharides linked together in a single chain. These are called Polysaccharides.
Plants use this for energy storage e.g. Potatoes
Two types
Amylose - Long strait unbranched chains
Pectins - many linked short Amylose chains

Starch
Cellulose is made of long polysaccharide chains
Plants use this for structure (e.g. Wood) - not very digestible
Due to the reverse orientation of the monosaccharide sububnits, digestive enzymes cannot hydrolize the bonds between them

CLEULOSE

LIPIDS

Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling molecules.
Other lipids are adipose tissue, ear wax, oils.
Lipids chains can be up to 127 molecules long.

Saturated = saturated with the hydrogen molecule

Protein – are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code.

Types of tissue

Amino acids are molecules containing both amine and carboxyl functional groups. These molecules are particularly important in biochemistry, where this term refers to alpha-amino acids with the general formula H2NCHRCOOH, where R is an organic substituent. In the alpha amino acids, the amino and carboxylate groups are attached to the same carbon atom, which is called the α–carbon.

Amino Acid

A peptide bond (amide bond) is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amine group of the other molecule, thereby releasing a molecule of water (H2O). This is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids. The resulting CO-NH bond is called a peptide bond, and the resulting molecule is an amide. The four-atom functional group -C (=O) NH- is called an amide group or (in the context of proteins) a peptide group. Polypeptides and proteins are chains of amino acids held together by peptide bonds, as is the backbone of PNA. Polyamides, such as nylons and aramids, are synthetic molecules (polymers) that possess peptide bonds.

Peptide bond formed through dehydration synthesis. Peptide bonds and structural – enzymatic A nucleic acid is a macromolecule composed of chains of monomeric nucleotides. In biochemistry these molecules carry genetic information or form structures within cells. The most common nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nucleic acids are universal in living things, as they are found in all cells and viruses. Nucleic acids were first discovered by Friedrich Miescher in 1871.

Types Of Tissue Connective tissue -Connective tissues are fibrous tissues. They are comprised of cells separated by non-living material, which is called extracellular matrix. Connective tissue holds other tissues together such as in the formation of organs, and has the ability to stretch and contract passively. Bone, often referred to as osseous tissue, and blood are examples of specialized connective tissues. Conective tissues are cells that are suspended in a matrix of their own secretions.
Muscle tissue -Muscle cells form the active contractile tissue of the body known as muscle tissue. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle tissue is separated into three distinct categories: visceral or smooth muscle, which is found in the inner linings of organs; skeletal muscle, in which is found attached to bone providing for gross movement; and cardiac muscle which is found in the heart, allowing it to contract and pump blood throughout an organism.
Nervous tissue- Cells comprising the central nervous system and peripheral nervous system are classified as neural tissue. In the central nervous system, neural tissue forms the brain, cranial nerves and spinal cord and, in the peripheral nervous system forms the peripheral nerves, inclusive of the motor neurons.
Epithelial tissue- The epithelial tissues are formed by layers of cells that cover organ surfaces such as the surface of the skin, the airways, the reproductive tract, and the inner lining of the digestive tract. The cells comprising an epithelial layer are linked via semi-permeable, tight junctions; hence, this tissue provides a barrier between the external environment and the organism it covers. In addition to this protective function, epithelial tissue may also be specialized to function in secretion and absorption.

squamous is an epithelium characterized by its most superficial layer consisting of flat, scale-like cells called squamous cell. Epithelium may possess only one layer of these cells, in which case it is referred to as simple squamous epithelium; or it may possess multiple layers, referred to them as stratified squamous epithelium. Both types perform differing functions, ranging from nutrient exchange to protection.

Cuboidal epithelia are epithelial cells having a cube-like shape; that is, their width is approximately equal to their height. They may exist in single layers (simple cuboidal epithelium) or multiple layers (stratified cuboidal epithelium) depending on their location (and thus function) in the body.

columnar refers to the shape of epithelial cells that are taller than they are wide.[1] Form follows function in biology, and columnar morphorphology hints at the functions of the cell. Columnar cells are important in absorption and movement of mucus. The cells may or may not bear microvilli (involved in maximizing the surface area for intestinal absorption) or cilia (involved in moving mucus and trapped material up the respiratory passages to be expectorated or swallowed). Columnar epithelium may be simple or stratified. Simple columnar epithelium is most common and involves one layer of cells attached to a basement membrane. The nucleus is closer to the basal aspect of the cell than the apical aspect. Single stratification tends to indicate absorptive function. Stratified columnar epithelium is rare but can be found in salivary glands. It consists of a layer of columnar epithelium resting on top of at least one other layer of eithelial cells, which may have any shape (columnar, cuboidal, or squamous). Stratification in cuboidal tissue has a secretory function.

A pseudostratified epithelium is a type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia. As it rarely occurs as squamous or cuboidal epithelia, it is usually considered synonymous with the term pseudostratified columnar epithelium.
The term pseudostratified is derived from the appearance of this epithelium in section which conveys the erroneous (pseudo means false) impression that there is more than one layer of cells, when in fact this is a true simple epithelium since all the cells rest on the basal lamina. The nuclei of these cells, however, are disposed at different levels, thus creating the illusion of cellular stratification. Not all ciliated cells extend to the luminal surface; such cells are capable of cell division providing replacements for cells lost or damaged.
Goblet cells are glandular simple columnar epithelial cells whose sole function is to secrete mucus. On to the surface of the human body, for example sweat glands, sebaceous glands. All goblet cells are exocrine.

Exocrine glands secret into ducts, whereas endocrine glands secret directly into the blood stream.
SKIN - is the outer covering of the body. In humans, it is the largest organ of the integumentary system made up of 3 layers of tissue, and guards the underlying muscles, bones, ligaments and internal organs.
Skin is composed of three primary layers: * the epidermis, which provides waterproofing and serves as a barrier to infection; * the dermis, which serves as a location for the appendages of skin; and * the hypodermis or subcutaneous adipose layer.
Epidermis - is the outermost layer of the skin. It forms the waterproof, protective wrap over the body's surface and is made up of stratified squamous epithelium with an underlying basal lamina.

Dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptor/nerve endings that provide the sense of touch and heat. It contains the hair follicles, sweat glands, sebaceous glands, apocrine glands, lymphatic vessels and blood vessels. The blood vessels in the dermis provide nourishment and waste removal from its own cells as well as from the Stratum basale of the epidermis.

subcutaneous - is a layer of fat that lies between the dermis of the skin and underlying fascia. Subcutaneous fat insulates the body, absorbs trauma, and is a reserve energy source.

BONES are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. Because bones come in a variety of shapes and have a complex internal and external structure they are lightweight, yet strong and hard, in addition to fulfilling their many other functions. One of the types of tissue that makes up bone is the mineralized osseous tissue, also called bone tissue, that gives it rigidity and a honeycomb-like three-dimensional internal structure. Other types of tissue found in bones include marrow, endosteum and periosteum, nerves, blood vessels and cartilage. There are 206 bones in the adult human body and 270 in an infant.

There are five types of bones in the human body: long, short, flat, irregular and sesamoid. * Long bones are characterized by a shaft, the diaphysis, that is much greater in length than width. They are comprised mostly of compact bone and lesser amounts of marrow, which is located within the modularly cavity, and spongy bone. Most bones of the limbs, including those of the fingers and toes, are long bones. The exceptions are those of the wrist, ankle and kneecap. * Short bones are roughly cube-shaped, and have only a thin layer of compact bone surrounding a spongy interior. The bones of the wrist and ankle are short bones, as are the sesamoid bones. * Flat bones are thin and generally curved, with two parallel layers of compact bones sandwiching a layer of spongy bone. Most of the bones of the skull are flat bones, as is the sternum. * Irregular bones do not fit into the above categories. They consist of thin layers of compact bone surrounding a spongy interior. As implied by the name, their shapes are irregular and complicated. The bones of the spine and hips are irregular bones. * Sesamoid bones are bones embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the leverage of the muscle is increased. Examples of sesamoid bones are the patella and the pisiform.

Compared to woven bone, lamellar bone formation takes place more slowly. The orderly deposition of collagen fibers restricts the formation of osteoid to about 1 to 2 um per day. Lamellar bone requires a relatively flat surface to lay the collagen fibers in parallel or concentric layers.

The long bones are those that are longer than they are wide, and grow primarily by elongation of the diaphysis, with an epiphysis at the ends of the growing bone. The ends of epiphyses are covered with a hyaline cartilage ("articular cartilage"). The longitudinal growth of long bones is a result of endochondral ossification at the epiphyseal plate. Bone growth in length is stimulated by the production of growth hormone (GH), a secretion of the anterior lobe of the pituitary gland.
The long bones include the, femurs, tibias, and fibulas of the legs, the humerous, radious, and ulnas of the arms, metacarpals and metatarsals of the hands and feet, and the phalanges of the fingers and toes. The long bones of the human leg comprise nearly half of adult height. The other primary skeletal component of height is the spine and skull.
The outside of the bone consists of a layer of connective tissue called the periosteum. Additionally, the outer shell of the long bone is compact bone, then a deeper layer of cancellous bone (spongy bone) which contains red bone marrow. The interior part of the long bone is the medullary cavity with the inner core of the bone cavity being composed of (in adults) of yellow marrow.

epiphyseal plate (or epiphysial plate, physis, or growth plate) is a hyaline cartilage plate in the metaphysis at each end of a long bone. The plate is found in children and adolescents; in adults, who have stopped growing, the plate is replaced by an epiphyseal line.

Periosteum is a membrane that lines the outer surface of all bones, except at the joints of long bones. Endosteum lines the inner surface of all bones.

The axial skeleton consists of the 80 bones in the head and trunk of the human body. It is composed of five parts; the human skull, the ossicles of the inner ear, the hyoid bone of the throat, the rib cage, and the vertebral column. The axial skeleton and the appendicular skeleton together form the complete skeleton.
Flat bones house the brain, spinal cord, and other vital organs. This article mainly deals with the axial skeletons of humans; however, it is important to understand the evolutionary lineage of the axial skeleton. The human axial skeleton consists of 80 different bones. It is the central core of the body and where the appendicular skeleton attaches. As the skeleton grows older the bones get weaker with the exception of the skull. The skull remains strong so as to protect the brain from injury. * Cranial Bones (8), Parietal (2), Temporal (2), Frontal (1), Occipital (1), Ethmoid (1), Sphenoid (1) * Facial Bones (14) - Maxilla (2), Zygomatic (2), Mandible (1), Nasal (2), Palatine (2), Inferior nasal concha (2), Lacrimal (2), Vomer (1) * Ossicles (6) * Malleus (2) * Incus (2) * Stapes (2) * Hyoid bone (1) U-shape bone located in the neck. It anchors the tongue and is associated with swallowing. * Vertebral Column (26) - Cervical vertebrae (7), Thoracic vertebrae (12), Lumbar vertebrae (5), Sacrum (5) (fused), Coccyx (4) (fused, varies between 3-5), Thoracic cage (25) * Sternum (1) * Ribs (24)

The skull is a bony structure found in the head of many animals. The skull supports the structures of the face and protects the head against injury.
The skull can be divided into two parts: the cranium and the mandible. A skull that is missing a mandible is only a cranium; this is the source of a very commonly made error in terminology.
In humans, the adult skull is normally made up of 22 bones (8 cranial, 14 facial bones)
Except for the mandible, all of the bones of the skull are joined together by sutures, rigid articulations permitting very little movement. Eight bones form of the cranium (braincase)—including the frontal, parietals, occipital bone, sphenoid, temporals and ethmoid—a protective vault surrounding the brain. Fourteen bones form the Face, the bones supporting the face.
The hyoid bone, supporting the tongue, is usually not considered as part of the skull either, as it does not articulate with any other bones. The skull is a protector of the brain.

The bones of the Cranium:
The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions: a vertical portion, the squama frontalis, corresponding with the region of the forehead. An orbital or horizontal portion, the pars orbitalis, which enters into the formation of the roofs of the orbital and nasal cavities. The anterior most bone of the human skull. Forms the anterior wall and floor of the cranial cavity, also forms the roof of the eye orbits.
Supracranial ridge – Found on male skulls and usually absent on female skulls.
The supraorbital ridge, or brow ridge, refer to a bony ridge located above the eye sockets of all primates. In Homo sapiens sapiens (modern humans) the eyebrows are located on their lower margin.
The supraorbital foramen is a bony elongated path located above the orbit (eye socket) and under the forehead. The supraorbital foramen lies directly under the eyebrow.
The glabella is the space between the eyebrows and above the nose. It is slightly elevated, and joins the two superciliary ridges.

The parietal bones are bones in the human skull and form, by their union, the sides and roof of the cranium. Each bone is irregularly quadrilateral in form, and has two surfaces, four borders, and four angles.
The external surface of the parietal bone is convex, smooth, and marked near the center by an eminence, the parietal eminence (parietal tuber), which indicates the point where ossification commenced. When measured from point to point it is the widest part of the skull.

The parietal bones are joined at the coronal suture lines.
The parietal bones join the frontal bone at the sagital suture.

The occipital bone, a saucer-shaped membrane bone situated at the back and lower part of the cranium, is trapezoid in shape and curved on itself. It is pierced by a large oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal. The occipital bones forms the posterior wall and floor of the cranium * The curved, expanded plate behind the foramen magnum is named the squama occipitalis. * The thick, somewhat quadrilateral piece in front of the foramen is called the basilar part of occipital bone. * On either side of the foramen are the lateral parts of occipital bone.
The occipital condyles are undersurface facets of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra.
The condyles are oval or kidney-shaped in shape, and their anterior extremities, directed forward and medial ward, are closer together than their posterior, and encroach on the basilar portion of the bone; the posterior extremities extend back to the level of the middle of the foramen magnum.
The articular surfaces of the condyles are convex from before backward and from side to side, and look downward and lateralward.
To their margins are attached the capsules of the atlantoöccipital articulations, and on the medial side of each is a rough impression or tubercle for the alar ligament.
At the base of either condyle the bone is tunnelled by a short canal, the hypoglossal canal.
Condyle - a rounded part at the end of a bone that forms a moving joint with a cup-shaped cavity in another bone. The ball part of a ball-and-socket joint such as the hip or shoulder joint is a condyle.

The temporal bones are situated at the sides and base of the skull. The temporal bone supports that part of the face known as the temple.
Thin flat and scale like 2 regions squamous portion (very thin and flat part and the Petrus portion – temporal processes zymora one of two bones in the check.
The ear canal (external auditory meatus, external acoustic meatus), is a tube running from the outer ear to the middle ear. The human ear canal extends from the pinna to the eardrum and is about 26 mm in length and 7 mm in diameter.
Zygomatic process is a protrusion from the rest of the skull, like the bumper of a car. Most of it belongs to the zygomatic bone, and could therefore be called the zygomatic process of the zygomatic bone. However, there are other bones contributing to it too, namely the frontal bone, maxilla and temporal bone, which therefore form: * Zygomatic process of frontal bone * Zygomatic process of maxilla * Zygomatic process of temporal bone
The term zygomatic derives from the Latin zyosislymore meaning malar bone or cheekbone. The zygomatic process is occasionally referred to as the zygoma, but this term usually refers to the zygomatic bone or occasionally the zygomatic arch. mandibular fossa - a deep concavity in the temporal bone at the root of the zygomatic arch that receives the condyle of the mandible

The temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. There are two TMJs, one on either side, working in unison. The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium (skull), and the lower jaw bone called the mandible. The unique feature of the TMJs is the articular disc. The disc is composed of fibrocartilagenous tissue (like the firm and flexible elastic cartilage of the ear) which is positioned between the two bones that form the joint. The TMJs are one of the only synovial joints in the human body with an articular disc, another being the sternoclavicular joint. The disc divides each joint into two. The lower joint compartment formed by the mandible and the articular disc is involved in rotational movement (opening and closing movements). The upper joint compartment formed by the articular disk and the temporal bone is involved in translational movements (sliding the lower jaw forward or side to side). The part of the mandible which mates to the under-surface of the disc is the condyle and the part of the temporal bone which mates to the upper surface of the disk is the glenoid (or mandibular) fossa.
The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process. Its size and form vary somewhat; it is larger in the male than in the female.

The styloid process is a slender pointed piece of bone just below the ear. It projects down and forward from the inferior surface of the temporal bone, and serves as an anchor point for several muscles associated with the tongue and larynx.
Its proximal part (tympanohyal) is ensheathed by the vaginal process of the tympanic portion.
Its distal part (stylohyal) gives attachment to the following: stylohyoid ligament, stylomandibular ligament, styloglossus muscle (innervated by the hypoglossal nerve), stylohyoid muscle (innervated by the facial nerve), stylopharyngeus muscle (innervated by the glossopharyngeal nerve), The stylohyoid ligament extends from the apex of the process to the lesser cornu of the hyoid bone, and in some instances is partially, in others completely, ossified.

The sphenoid bone is situated at the base of the skull in front of the temporal and basilar part of the occipital. It somewhat resembles a bat with its wings extended, and is divided into a median portion or body, two great and two small wings extending outward from the sides of the body, and two pterygoid processes which project from it below. Body (corpus sphenoidale).—The body, more or less cubical in shape, is hollowed out in its interior to form two large cavities, the sphenoidal air sinuses, which are separated from each other by a septum. Surfaces.—The superior surface of the body presents in front a prominent spine, the ethmoidal spine, for articulation with the cribriform plate of the ethmoid; behind this is a smooth surface slightly raised in the middle line, and grooved on either side for the olfactory lobes of the brain. This surface is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove and still more posteriorly, a deep depression, the sella turcica, the deepest part of which lodges the hypophysis cerebri and is known as the fossa hypophyseos. The anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the middle clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellæ, ending at its superior angles in two tubercles, the posterior clinoid processes, the size and form of which vary considerably in different individuals. The posterior clinoid processes deepen the sella turcica, and give attachment to the tentorium cerebelli. On either side of the dorsum sellæ is a notch for the passage of the abducent nerve, and below the notch a sharp process, the petrosal process, which articulates with the apex of the petrous portion of the temporal bone, and forms the medial boundary of the foramen lacerum.Behind the dorsum sellæ is a shallow depression, the clivus, which slopes obliquely backward, and is continuous with the groove on the basilar portion of the occipital bone; it supports the upper part of the pons. the sphenoidal conchæ leaving in the articulated skull a round opening at the upper part of each sinus by which it communicates with the upper and back part of the nasal cavity and occasionally with the posterior ethmoidal air cells. The lateral margin of the anterior surface is serrated, and articulates with the lamina papyracea of the ethmoid, completing the posterior ethmoidal cells; the lower margin articulates with the orbital process of the palatine bone, and the upper with the orbital plate of the frontal bone. The inferior surface presents, in the middle line, a triangular spine, the sphenoidal rostrum, which is continuous with the sphenoidal crest on the anterior surface, and is received in a deep fissure between the alæ of the vomer. On either side of the rostrum is a projecting lamina, the vaginal process, directed medialward from the base of the medial pterygoid plate, with which it will be described.
The Great Wings (alæ magnæ).—The great wings, or ali-sphenoids, are two strong processes of bone, which arise from the sides of the body, and are curved upward, lateralward, and backward; the posterior part of each projects as a triangular process which fits into the angle between the squama and the petrousportion of the temporal and presents at its apex a downwardly directed process, the spina angularis (sphenoidal spine)

The ethmoid is a bone in the skull that separates the nasal cavity from the brain. As such, it is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction. The ethmoid bone is one of the bones that makes up the orbit of the eye.

The ethmoid articulates with fifteen bones: four of the neurocranium—the frontal, and the sphenoid (at the sphenoidal body and at the sphenoidal conchae). eleven of the viscerocranium—, two Nasal bones, two maxillae, two lacrimals, two palatines, two inferior nasal conchae, and the vomer

The calvaria (or calva, or skullcap) is the upper part of the cranium and surrounds the cranial cavity containing the brain. It is formed by the following bones: frontal bone, parietal bones, temporal bones, occipital bone, sphenoid bone, ethmoid bone.
Facial bones: 14 bones of the face: mandible, maxilla (2), palatine bone (2), zygomatic bone (2), nasal bone (2), lacrimal bone (2), vomer bone, inferior nasal conchae (2).

The mandible or inferior maxillary bone forms the lower jaw and holds the lower teeth in place. It also refers to both the upper and lower sections of the beaks of birds; in this case the lower mandible corresponds to the mandible of humans while the "upper mandible" is functionally equivalent to the human maxilla but mainly consists of the premaxillary bones.

The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis.
The alveolar process of the maxilla holds the upper teeth, and is referred to as the maxillary arch. The maxilla attaches laterally to the Zygomatic bones (cheek bones).
The maxilla assists in forming the boundaries of three cavities: the roof of the mouth, the floor and lateral wall of the nasal antrum, the floor of the orbit, The maxilla also enters into the formation of two fossae: the infratemporal and pterygopalatine, and two fissures, the inferior orbital and pterygomaxillary.

Lacrimal bone (2)- The lacrimal bone, the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders.
The lateral or orbital surface is divided by a vertical ridge, the posterior lacrimal crest, into two parts.
In front of this crest is a longitudinal groove, the lacrimal sulcus (sulcus lacrimalis), the inner margin of which unites with the frontal process of the maxilla, and the lacrimal fossa is thus completed. The upper part of this fossa lodges the lacrimal sac, the lower part, the nasolacrimal duct.
The portion behind the crest is smooth, and forms part of the medial wall of the orbit.
The crest, with a part of the orbital surface immediately behind it, gives origin to the lacrimal part of the Orbicularis oculi and ends below in a small, hook-like projection, the lacrimal hamulus, which articulates with the lacrimal tubercle of the maxilla, and completes the upper orifice of the nasolacrimal canal; the hamulus sometimes exists as a separate piece, and is then called the lesser lacrimal bone.
The zygomatic bone (cheekbone, malar bone) is a paired bone of the human skull. It articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. The zygomatic is homologous to the jugal bone of other tetrapods. It is situated at the upper and lateral part of the face and forms the prominence of the cheek, part of the lateral wall and floor of the orbit, and parts of the temporal and infratemporal fossae. It presents a malar and a temporal surface; four processes, the frontosphenoidal, orbital, maxillary, and temporal; and four borders.
The malar surface is convex and perforated near its center by a small aperture, the zygomaticofacial foramen, for the passage of the zygomaticofacial nerve and vessels; below this foramen is a slight elevation, which gives origin to the Zygomaticus.
The temporal surface, directed posteriorly and medially, is concave, presenting medially a rough, triangular area, for articulation with the maxilla (articular surface), and laterally a smooth, concave surface, the upper part of which forms the anterior boundary of the temporal fossa, the lower a part of the infratemporal fossa. Near the center of this surface is the zygomaticotemporal foramen for the transmission of the zygomaticotemporal nerve.
The palatine bone is a bone in many species of the animal kingdom, commonly termed the palatum (Latin palatum; unrelated to palatium 'palace', from which other senses of palatine derive).
It is situated at the back part of the nasal cavity between the maxilla and the pterygoid process of the sphenoid.
It contributes to the walls of three cavities: the floor and lateral wall of the nasal cavity, the roof of the mouth, and the floor of the orbit; it enters into the formation of two fossæ, the pterygopalatine and pterygoid fossæ; and one fissure, the inferior orbital fissure.
The palatine bone somewhat resembles the letter L, and consists of a Horizontal plate of palatine bone and a Perpendicular plate of palatine bone and three outstanding processes—viz., the Pyramidal process of palatine bone, which is directed backward and lateralward from the junction of the two parts, and the Orbital process of palatine bone and Sphenoidal process of palatine bone, which surmount the vertical part, and are separated by a deep notch, the sphenopalatine notch.
The human palatine articulates with six bones: the sphenoid, ethmoid, maxilla, inferior nasal concha, vomer and opposite palatine.

The vomer is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones.
The vomer is situated in the median plane, but its anterior portion is frequently bent to one or other side.
It is thin, somewhat quadrilateral in shape, and forms the hinder and lower part of the nasal septum; it has two surfaces and four borders.
The surfaces are marked by small furrows for blood vessels, and on each is the nasopalatine groove, which runs obliquely downward and forward, and lodges the nasopalatine nerve and vessels.
Borders -The superior border, the thickest, presents a deep furrow, bounded on either side by a horizontal projecting ala of bone; the furrow receives the rostrum of the sphenoid, while the margins of the alæ articulate with the vaginal processes of the medial pterygoid plates of the sphenoid behind, and with the sphenoidal processes of the palatine bones in front. The inferior border articulates with the crest formed by the maxillæ and palatine bones. The anterior border is the longest and slopes downward and forward. Its upper half is fused with the perpendicular plate of the ethmoid; its lower half is grooved for the inferior margin of the septal cartilage of the nose. The posterior border is free, concave, and separates the choanae. It is thick and bifid above, thin below.
Articulations - The vomer articulates with six bones: * two of the cranium, the sphenoid and ethmoid. * four of the face, the two maxillae; and the two palatine bones.
It also articulates with the septal cartilage of the nose.

The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose. Each has two surfaces and four borders. The outer surface is concavoconvex from above downward, convex from side to side; it is covered by the Procerus and Compressor naris, and perforated about its center by a foramen, for the transmission of a small vein. The inner surface is concave from side to side, and is traversed from above downward, by a groove for the passage of a branch of the nasociliary nerve.
The nasal articulates with four bones: two of the cranium, the frontal and ethmoid, and two of the face, the opposite nasal and the maxilla.
The inferior nasal concha (Inferior Turbinated Bone) is one of the turbinates in the nose. It extends horizontally along the lateral wall of the nasal cavity [Fig. 1] and consists of a lamina of spongy bone, curled upon itself like a scroll. Each inferior nasal concha is considered a facial pair of bones since they arise from the maxillae bones and projects horizontally into the nasal cavity. They are also termed 'inferior nasal turbinates' because they function similar to that of a turbine. As the air passes through the turbinates, the air is churned against these mucosa-lined bones in order to receive warmth, moisture and cleansing. Superior to inferior nasal concha are the middle nasal concha and superior nasal concha which arise from the cranial portion of the skull. Hence, these two are considered as a part of the cranial bones.
It has two surfaces, two borders, and two extremities.
The medial surface is convex, perforated by numerous apertures, and traversed by longitudinal grooves for the lodgement of vessels.
The lateral surface is concave, and forms part of the inferior meatus.
Its upper border is thin, irregular, and connected to various bones along the lateral wall of the nasal cavity.
It may be divided into three portions: of these, the anterior articulates with the conchal crest of the maxilla; the posterior with the conchal crest of the palatine; the middle portion presents three well-marked processes, which vary much in their size and form.
Of these, the anterior or lacrimal process is small and pointed and is situated at the junction of the anterior fourth with the posterior three-fourths of the bone: it articulates, by its apex, with the descending process of the lacrimal bone, and, by its margins, with the groove on the back of the frontal process of the maxilla, and thus assists in forming the canal for the nasolacrimal duct.
Behind this process a broad, thin plate, the ethmoidal process, ascends to join the uncinate process of the ethmoid; from its lower border a thin lamina, the maxillary process, curves downward and lateralward; it articulates with the maxilla and forms a part of the medial wall of the maxillary sinus.
The inferior border is free, thick, and cellular in structure, more especially in the middle of the bone.
The alveolar process is the thickened ridge of bone that contains the tooth sockets on bones that bear teeth. It is also referred to as the alveolar bone. In humans, the tooth-bearing bones are the maxilla and the mandible. The mineral content of alveolar bone is mostly hydroxyapatite, which is also found in enamel as the main inorganic substance.
On the maxilla, the alveolar process is a ridge on the inferior surface, and on the mandible it is a ridge on the superior surface. It makes up the thickest part of the maxilla.
The hyoid bone (lingual bone) is a horseshoe shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.
It is the only bone in the human skeleton not articulated to any other bone. It is held in place by thyroid ligaments. The hyoid bone provides attachment to the muscles of the floor of the mouth and the tongue above, the larynx below, and the epiglottis and pharynx behind.
The following muscles are attached to the hyoid: (Superior):Middle pharyngeal constrictor muscle, Hyoglossus muscle, Digastric muscle, Stylohyoid muscle, Geniohyoid muscle, Mylohyoid muscle, Genioglossus.
(Inferior): Thyrohyoid muscle, Omohyoid muscle, Sternohyoid muscle

The ossicles (also called auditory ossicles) are the three smallest bones in the human body. They are contained within the middle ear space and serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss. The term "ossicles" literally means "tiny bones" and commonly refers to the auditory ossicles, though the term may refer to any small bone throughout the body. The ossicles are, in order from the eardrum to the inner ear, the malleus, incus, and stapes. Terms that, in Latin, are translated as the hammer, the anvil, and the stirrup. * The malleus articulates with the incus and is attached to the tympanic membrane (eardrum), from which vibrational energy is passed. * The incus is connected to both the other bones. * The stapes articulates with the incus and is attached to the membrane of the fenestra ovalis, the elliptical or oval window or opening between the middle ear and the vestibule of the inner ear.
Function
As sound waves vibrate the tympanic membrane (eardrum), it in turn moves the nearest ossicle, the malleus, to which it is attached. The malleus then transmits the vibrations, via the incus, to the stapes, and so ultimately to the membrane of the fenestra ovalis, the opening to the vestibule of the inner ear.
The ossicles give the eardrum mechanical advantage via lever action and a reduction in the area of force distribution; the resulting vibrations would be much smaller if the sound waves were transmitted directly from the outer ear to the oval window. However, the extent of the movements of the ossicles is controlled (and constricted) by certain muscles attached to them (the tensor tympani and the stapedius). It is believed that these muscles can contract to dampen the vibration of the ossicles, in order to protect the inner ear from excessively loud noise (theory 1) and that they give better frequency resolution at higher frequencies by reducing the transmission of low frequencies (theory 2) (see acoustic reflex). These muscles are more highly developed in bats and serve to block outgoing cries of the bats during echolocation (SONAR).
Occasionally the joints between the ossicles become rigid. One condition, otosclerosis, results in the fusing of the stapes to the oval window. This reduces hearing and may be treated surgically.
Vertebral Column
In human anatomy, the vertebral column (backbone or spine) is a column usually consisting of 24 vertebrae,[1] the sacrum, intervertebral discs, and the coccyx situated in the dorsal aspect of the torso, separated by spinal discs. It houses the spinal cord in its spinal canal.
Individual vertebrae named according to region and position, from superior to inferior * Cervical – 7 vertebrae (C1-C7) * C1 is known as "atlas" and supports the head, C2 is known as "axis" * Possesses bifid spinous processes, which is absent in C1 and C7 * Small-bodied * Thoracic – 12 vertebrae (T1-T12) * Distinguished by the presence of costal facets for the articulation of the heads of ribs * Body is intermediate in size between the cervical and lumbar vertebrae * Lumbar – 5 vertebrae (L1-L5) * Has a large body * Does not have costal facets nor transverse process foramina * Sacral – 5 (fused) vertebrae (S1-S5) * Coccygeal – 4 (3-5) (fused) vertebrae (Tailbone)
A vertebra (plural: vertebrae) is an individual bone in the flexible column that defines vertebrate animals, e.g. humans. The vertebral column encases and protects the spinal cord, which runs from the base of the cranium down the dorsal side of the animal until reaching the pelvis. From there, vertebra continue into the tail.
There are normally thirty-three (33) vertebrae in humans, including the five that are fused to form the sacrum (the others are separated by intervertebral discs) and the four coccygeal bones which form the tailbone. The upper three regions comprise the remaining 24, and are grouped under the names cervical (7 vertebrae), thoracic (12 vertebrae) and lumbar (5 vertebrae), according to the regions they occupy. This number is sometimes increased by an additional vertebra in one region, or it may be diminished in one region, the deficiency often being supplied by an additional vertebra in another. The number of cervical vertebrae is, however, very rarely increased or diminished.
With the exception of the first and second cervical, the true or movable vertebrae (the upper three regions) present certain common characteristics which are best studied by examining one from the middle of the thoracic region.
General structure
A typical vertebra consists of two essential parts: an anterior (front) segment, which is the vertebral body; and a posterior part – the vertebral (neural) arch – which encloses the vertebral foramen. The vertebral arch is formed by a pair of pedicles and a pair of laminae, and supports seven processes, four articular, two transverse, and one spinous, the latter also being known as the neural spine.
When the vertebrae are articulated with each other, the bodies form a strong pillar for the support of the head and trunk, and the vertebral foramina constitute a canal for the protection of the medulla spinalis (spinal cord). In between every pair of vertebrae are two apertures, the intervertebral foramina, one on either side, for the transmission of the spinal nerves and vessels. Two transverse process and one spinous process are posterior to (behind) the vertebral body. The spinous process comes out the back, one transverse process comes out the left, and one on the right. The spinous processes of the cervical and lumbar regions can be felt through the skin. Superior and inferior articular facets on each vertebra act to restrict the range of movement possible. These facets are joined by a thin portion of the neural arch called the pars interarticularis.
Special cervical vertebrae (C1, C2, and C7) * C1 or atlas: The Atlas is the topmost vertebra, and – along with C2 – forms the joint connecting the skull and spine. Its chief peculiarity is that it has no body, and this is due to the fact that the body of the atlas has fused with that of the next vertebra. * C2 or axis: It forms the pivot upon which C1 rotates. The most distinctive characteristic of this bone is the strong odontoid process (dens) which rises perpendicularly from the upper surface of the body. The body is deeper in front than behind, and prolonged downward anteriorly so as to overlap the upper and front part of the third vertebra. * C7 or vertebra prominens: The most distinctive characteristic of this vertebra is the existence of a long and prominent spinous process, hence the name vertebra prominens. In some subjects, the seventh cervical vertebra is associated with an abnormal pair of ribs, known as cervical ribs. These ribs are usually small, but may occasionally compress blood vessels (such as the subclavian artery) or nerves in the brachial plexus, causing unpleasant symptoms.
General characteristics (C3-C6)
These are the general characteristics of the third through sixth cervical vertebrae. (The first, second, and seventh vertebrae are extraordinary, and detailed later.) * The body of these four vertebrae is small, and broader from side to side than from front to back. * The anterior and posterior surfaces are flattened and of equal depth; the former is placed on a lower level than the latter, and its inferior border is prolonged downward, so as to overlap the upper and forepart of the vertebra below. * The upper surface is concave transversely, and presents a projecting lip on either side; * the lower surface is concave from front to back, convex from side to side, and presents laterally shallow concavities which receive the corresponding projecting lips of the underlying vertebra. * The pedicles are directed laterally and backward, and are attached to the body midway between its upper and lower borders, so that the superior vertebral notch is as deep as the inferior, but it is, at the same time, narrower. * The laminae are narrow, and thinner above than below; the vertebral foramen is large, and of a triangular form. * The spinous process is short and bifid, the two divisions being often of unequal size. * The superior and inferior articular processes of neighboring vertebrae often fuse on either or both sides to form an articular pillar, a column of bone which projects laterally from the junction of the pedicle and lamina. * The articular facets are flat and of an oval form: * the superior face backward, upward, and slightly medially. * the inferior face forward, downward, and slightly laterally. * The transverse processes are each pierced by the foramen transversarium, which, in the upper six vertebrae, gives passage to the vertebral artery and vein, as well as a plexus of sympathetic nerves. Each process consists of an anterior and a posterior part. These two parts are joined, outside the foramen, by a bar of bone which exhibits a deep sulcus on its upper surface for the passage of the corresponding spinal nerve. * The anterior portion is the homologue of the rib in the thoracic region, and is therefore named the costal process or costal element. It arises from the side of the body, is directed laterally in front of the foramen, and ends in a tubercle, the anterior tubercle. * The posterior part, the true transverse process, springs from the vertebral arch behind the foramen, and is directed forward and laterally; it ends in a flattened vertical tubercle, the posterior tubercle.
The 12 thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. They are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper vertebrae being much smaller than those in the lower part of the region. They are distinguished by the presence of facets on the sides of the bodies for articulation with the heads of the ribs, and facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercles of the ribs.
These are the general characteristics of the second through eighth thoracic vertebrae. The first and ninth through twelfth vertebrae contain certain peculiarities, and are detailed below.
The bodies in the middle of the thoracic region are heart-shaped, and as broad in the antero-posterior as in the transverse direction. At the ends of the thoracic region they resemble respectively those of the cervical and lumbar vertebrae. They are slightly thicker behind than in front, flat above and below, convex from side to side in front, deeply concave behind, and slightly constricted laterally and in front. They present, on either side, two costal demi-facets, one above, near the root of the pedicle, the other below, in front of the inferior vertebral notch; these are covered with cartilage in the fresh state, and, when the vertebrae are articulated with one another, form, with the intervening intervertebral fibrocartilages, oval surfaces for the reception of the heads of the ribs.
The pedicles are directed backward and slightly upward, and the inferior vertebral notches are of large size, and deeper than in any other region of the vertebral column.
The laminae are broad, thick, and imbricated — that is to say, they overlap those of subjacent vertebrae like tiles on a roof.
The vertebral foramen is small, and of a circular form.
The spinous process is long, triangular on coronal section, directed obliquely downward, and ends in a tuberculated extremity. These processes overlap from the fifth to the eighth, but are less oblique in direction above and below.
The superior articular processes are thin plates of bone projecting upward from the junctions of the pedicles and laminae; their articular facets are practically flat, and are directed backward and a little lateralward and upward.
The inferior articular processes are fused to a considerable extent with the laminae, and project but slightly beyond their lower borders; their facets are directed forward and a little medialward and downward.
The transverse processes arise from the arch behind the superior articular processes and pedicles; they are thick, strong, and of considerable length, directed obliquely backward and lateralward, and each ends in a clubbed extremity, on the front of which is a small, concave surface, for articulation with the tubercle of a rib. *
In vertebrate anatomy, ribs (Latin costae) are the long curved bones which form the ribcage. In most vertebrates, ribs surround the chest (Greek:θώραξ, Latin thorax) they enable lungs to expand by expanding the chest, they also protect the lungs, heart, and other internal organs of the thorax.
Humans have 24 ribs (12 pairs). The first seven sets of ribs, known as "true ribs", are directly attached to the sternum through the costal cartilage. The following five sets are known as "false ribs", three of these sharing a common cartilaginous connection to the sternum, while the last two (eleventh and twelfth ribs) are termed floating ribs (costae fluitantes) or vertebral ribs. They are attached to the vertebrae only, and not to the sternum or cartilage coming off of the sternum. Some people are missing one of the two pairs of floating ribs, while others have a third pair. Rib removal is the surgical excision of ribs for therapeutic or cosmetic reasons.
The ribcage is separated from the lower abdomen by the thoracic diaphragm which controls breathing. When the diaphragm contracts, the ribcage and thoracic cavity are expanded, reducing intra-thoracic pressure and drawing air into the lungs.

The sternum is a long flat bone (or, in some models, set of three bones) shaped like a capital 'T' located in the center of the thorax (chest). It connects to the rib bones via cartilage, forming the anterior section of the rib cage with them, and thus helps to protect the lungs, heart and major blood vessels from physical trauma.
The sternum is an elongated, flattened bone, forming the middle portion of the anterior wall of the thorax. Its upper end supports the clavicles (Collar bones), and its margins articulate with the cartilages of the first seven pairs of ribs. Its top is also connected to the Sternocleidomastoid muscle. It consists of three parts, from above downward: * Manubrium * Body of sternum (gladiolus) * Xiphoid process
In its natural position, the inclination of the bone is oblique from above, downward and forward. It is slightly convex in front and concave behind; broad above, becoming narrowed at the point where the manubrium joins the body, after which it again widens a little to below the middle of the body, and then narrows to its lower extremity. Its average length in the adult is about 17 cm, and is rather longer in the male than in the female.
In early life its body is divided in three segments, called sternebrœ (singular: sternebra).
Articulations
The sternum articulates on either side with the clavicle and upper seven costal cartilages.

APPENDICULAR SKELETON
The appendicular skeleton is composed of 126 bones in the human body. The word appendicular is the adjective of the noun appendage which itself means a part that is joined to something larger. Functionally it is involved in locomotion (Lower limbs) of the axial skeleton and manipulation of objects in the environment (Upper limbs).
The appendicular skeleton is divided into six major regions:
1) Pectoral Girdles (4 bones) - Left and right Clavicle (2) and Scapula (2).
2) Arm and Forearm (6 bones) - Left and right Humerus (2) (Arm), Ulna (2) and Radius (2) (Fore Arm).
3) Hands (58 bones) - Left and right Carpal (16) (wrist), Metacarpal (10), Proximal phalanges (10), Middle phalanges (8), distal phalanges (10), and sesamoid (4).
4) Pelvis (2 bones) - Left and right os coxae (2) (ilium).
5) Thigh and leg (8 bones) - Femur (2) (thigh), Tibia (2), and Fibia (2) (leg).
6) Feet (48) - Tarsals (14) (ankle), Metatarsals (10), Proximal phalanges (10), middle phalanges (8), distal phalanges (10), and sesamoid (4).
The appendicular skeleton of 126 bones and the axial skeleton of 80 bones together form the complete skeleton of 206 bones in the human body.

Scapula - In anatomy, the scapula or shoulder blade, is the bone that connects the humerus (arm bone) with the clavicle (collar bone).
The scapula forms the posterior (back) located part of the shoulder girdle. In humans, it is a flat bone, roughly triangular in shape, placed on a posterolateral aspect of the thoracic cage.
On the lateral angle of the scapula is a shallow pyriform, articular surface, the glenoid cavity (or glenoid fossa of scapula from Greek: gléne, "socket"), which is directed lateralward and forward and articulates with the head of the humerus; it is broader below than above and its vertical diameter is the longest.
The cavity surface is covered with cartilage in the fresh state; and its margins, slightly raised, give attachment to a fibrocartilaginous structure, the glenoid labrum, which deepens the cavity.
Clavicle or collar bone is classified as a flat bone that makes up part of the shoulder girdle (pectoral girdle). It receives its name from the Latin clavicula ("little key") because the bone rotates along its axis like a key when the shoulder is abducted. This movement is palpable. In some people, particularly females who may have less fat in this region, the location of the bone is clearly visible as it creates a bulge in the skin. The clavicle is a doubly curved short bone that connects the arm (upper limb) to the body (trunk), located directly above the first rib. It acts as a strut to keep the scapula in position so the arm can hang freely. Medially, it articulates with the manubrium of the sternum (breast-bone) at the sternoclavicular joint. At its lateral end it articulates with the acromion of the scapula (shoulder blade) at the acromioclavicular joint. It has a rounded medial end and a flattened lateral end. the pelvis (plural pelves or pelvises) is the part of the trunk inferioposterior (below-behind) to the abdomen in the transition area between the trunk and the lower limbs.[1] The term is used to denote several structures: * the pelvic girdle or bony pelvis, the irregular ring-shaped bony structure connecting the spine to the femurs, * the pelvic cavity, the space enclosed by the pelvic girdle, subdivided into * the greater or false pelvis (inferior part of the abdominal cavity) and * the lesser or true pelvis which provides the skeletal framework for the perineum and the pelvic cavity (which are separated by the pelvic diaphragm), * the pelvic region.
"Pelvis" is the Latin word for a "basin" and the pelvis thus got its name from its shape. It is also known as hip girdle or coxa girdle.
In the adult human, it is formed in the posterior dorsal (back) by the sacrum and the coccyx, the caudal part of the axial skeleton, and laterally and posterior pair of hip bones, part of the appendicular skeleton or lower extremity. Until puberty, however, each hip bone consists of three separate bones yet to be fused — the ilium, ischium, and the pubis. The pelvis is thus composed of four parts and can consist up to ten bones or more
The pelvic girdle consists of the two hip bones. The hip bones are connected to each other anteriorly at the pubic symphysis, and posterior to the sacrum at the sacroiliac joints to form the pelvic ring. The ring is very stable and allows very little mobility, a prerequisite for transmitting loads from the trunk to the lower limbs.

Muscles

Mucles of the Head and Neck –

Occipito – Frontalis -AKA Epicranial Frontalis / Epicranial Occipitalis
Epicranial Frontalis O= Frontal bone
I= Anterior edge of the galea aponeurotica
A= Movement of the scalp.

Epicranial Occipitalis - The occipitalis is a small quadrilateral sheet.
Origin.—(i) occipital bone, and (2) a ridge upon the mastoid process.
Insertion.—The posterior border of the epicranial aponeurosis, of the occipital bone.
Action.—The occipitalis draws back the epicranial aponeurosis, and with it the scalp, which is intimately attached to its outer surface. Acting from behind, the frontalis raises the eyebrow. | |

Auricular Muscles – These muscle are less developed in most humans as they have become usless over evolution. Anterior, Superior, and posterior – Used in movement of the ear.

Muscles of facial expression – [cranial]

Corrigator Muscle (Corrugator supercilii)
O= Frontal bone
I= Frontal Bone
Action= draws the eyebrow downward and medialward, producing the vertical wrinkles of the forehead. It is the “frowning” muscle, and may be regarded as the principal muscle in the expression of suffering. It also contracts in order to prevent high sun glare, pulling the eyebrows toward the bridge of the nose, making a roof over the area above the middle corner of the eye and typical forehead furrows. Procerus Muscle:
O= Frontal bone
I= Frontal Bone
A= it helps to pull that part of the skin between the eyebrows downwards, which assists in flaring the nostrils. It can also contribute to an expression of anger. It is supplied by the buccal branch of CN VII and can produce transverse wrinkles.

orbicularis oculi:
O= Frontal, zygoma, and maxillia
I= Skin of the eye lid
A= Orbicularis oculi is a sphincter muscle around the eye and acts, in general, to narrow the eye opening and close the orbit of the eye. This muscle has important functions in protecting and moistening the eye as well as in expressive displays. These muscles constrict skin around the eye, reduce the eye opening, and close the eye. It has three parts, an outer or orbital part, an inner or palpebral part in the eyelids, and a small lacrimal part near the tear duct.

levator palpebrae superioris (or levator muscle of upper eyelid)
O=
I=
A= the muscle in the orbit that elevates the superior (upper) eyelid.

Depressor palpebrae Inferioris -
O=
I=
A= lower the eyelid

MUCLES OF FACIAL EXPRESSION [Mouth]

Orbicularis Oris– orbicularis oris muscle is the sphincter muscle around the mouth. It is also one of the muscles used in the playing of all brass instruments and some woodwind instruments. This muscle closes the mouth and puckers the lips when it contracts.
Origin: Maxilla and mandible
Insertion: Skin around the lips
Action: It is sometimes known as the kissing muscle because it is used to pucker the lips.

Levator Labii Superioris –
Origin Medial infra-orbital margin
Insertion Skin and muscle of the upper lip (labii superioris)
Actions Elevates the upper lip

Depressor labii inferioris muscle
Origin oblique line of the mandible, between the symphysis and the mental foramen Insertion integument of the lower lip, Orbicularis oris fibers, its fellow of the opposite side Actions depress the lower lip.

Zygomatic major
Origin anterior of zygomatic
Insertion modiolus of mouth Actions draws angle of mouth upward and laterally
The Zygomatic major is a muscle of the human body. It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly. Like all muscles of facial expression, the zygomatic major is innervated by the facial nerve (Cranial Nerve VII). The Zygomaticus extends from each zygomatic arch (cheekbone) to the corners of the mouth. It raises the corners of the mouth when a person smiles.
Zygomaticus minor muscle
Origin zygomatic bone Insertion skin of the upper lip
Actions elevates upper lip

zygomaticus minor is a muscle of facial expression. It originates from M. orbicularis oculi on the lateral face of the zygomatic bone and then inserts on the upper lip. It raises the corners of the mouth and is thus used in smiling.

Levator anguli oris Origin maxilla
Insertion modiolus
Actions smile (elevates angle of mouth) levator anguli oris (caninus) is a facial muscle of the mouth arising from the canine fossa, immediately below the infraorbital foramen. Its fibers are inserted into the angle of the mouth, intermingling with those of the Zygomaticus, Triangularis, and Orbicularis oris.

Buccinator muscle (Trumpeters Muscle) Origin from the alveolar processes of the maxillary bone and mandible, pterygomandibular raphe
Insertion in the fibres of the orbicularis oris Actions The buccinator compresses the cheeks against the teeth and is used in acts such as blowing. It is an assistant muscle of mastication (chewing).

Its action is to pull back the angle of the mouth and to flatten the cheek a rea, which aids in holding the cheek to the teeth during chewing. It arises from the outer surfaces of the alveolar processes of the maxilla and mandible, corresponding to the three molar teeth; and behind, from the anterior border of the pterygomandibular raphé which separates it from the Constrictor pharyngis superior. The fibers converge toward the angle of the mouth, where the central fibers intersect each other, those from below being continuous with the upper segment of the Orbicularis oris, and those from above with the lower segment; the upper and lower fibers are continued forward into the corresponding lip without decussation.
Risorius
Origin parotid fascia
Insertion modiolus Actions draw back angle of mouth
The risorius arises in the fascia over the parotid gland and, passing horizontally forward, superficial to the platysma, inserts onto the skin at the angle of the mouth. It is a narrow bundle of fibers, broadest at its origin, but varies much in its size and form. The risorius retracts the angle of the mouth to produce a smile, albeit an insincere-looking one that does not involve the skin around the eyes. Compare with a real smile, which raises the lips with the action of zygomaticus major and zygomaticus minor muscles and causes "crow's feet" around the eyes using the orbicularis oculi muscles.
Depressor anguli oris muscle
Origin tubercle of mandible
Insertion modiolus of mouth Actions depresses angle of mouth
At its origin it is continuous with the Platysma, and at its insertion with the Orbicularis oris and Risorius; some of its fibers are directly continuous with those of the Caninus, and others are occasionally found crossing from the muscle of one side to that of the other; these latter fibers constitute the Transversus menti.

Depressor Labbi inferiorius
Origin oblique line of the mandible, between the symphysis and the mental foramen
Insertion integument of the lower lip, Orbicularis oris fibers, its fellow of the opposite Actions depress the lower lip
The depressor labii inferioris (or quadratus labii inferioris) is a facial muscle that helps lower the bottom lip. This muscle arises from the oblique line of the mandible, and inserts on the skin of the lower lip, blending in with the orbicularis oris muscle. At its origin, depressor labii is continuous with the fibers of the platysma muscle. Much yellow fat is intermingled with the fibers of this muscle. The depressor labii inferioris is innervated by the facial nerve. This muscle helps to depress the lower lip. Mentalis
Origin anterior mandible
Insertion chin Actions elevates and wrinkles skin of chin, protrudes lower lip.
The Mentalis is situated at the tip of the chin. It raises and pushes up the lower lip, causing wrinkling of the chin, as in doubt or displeasure. Sometimes referred to as the "pouting muscle."
Its fibers arise from the incisive fossa of the mandible, then course vertically downward to insert in the skin of the chin.
Muscles of mastication

Platysma
Origin inferior clavicle and fascia of chest
Insertion mandible Actions Draws the corners of the mouth inferiorly and widens it (as in expressions of sadness and fright). Also draws the skin of the neck superiorly when teeth are clenched
Antagonist Masseter, Temporalis
The platysma is a superficial muscle that overlaps the sternocleidomastoid. It is a broad sheet arising from the fascia covering the upper parts of the pectoralis major and deltoid; its fibers cross the clavicle, and proceed obliquely upward and medially along the side of the neck. The anterior fibers interlace, below and behind the symphysis menti, with the fibers of the muscle of the opposite side; the posterior fibers cross the mandible, some being inserted into the bone below the oblique line, others into the skin and subcutaneous tissue of the lower part of the face. Many of these fibers blend with the muscles about the angle and lower part of the mouth. Sometimes fibers can be traced to the zygomaticus, or to the margin of the orbicularis oculi. Beneath the platysma, the external jugular vein descends from the angle of the mandible to the clavicle.
Digastric muscle
Origin anterior belly - digastric fossa (mandible); posterior belly - mastoid process of temporal bone Insertion Intermediate tendon (hyoid bone)
Actions Opens the jaw when the masseter and the temporalis are relaxed.
The digastric muscle (also digastricus) (named digastric as it has two bellies) is a small muscle located under the jaw. It lies below the body of the mandible, and extends, in a curved form, from the mastoid process to the symphysis menti. It belongs to the suprahyoid muscles group. A broad aponeurotic layer is given off from the tendon of the digastricus on either side, to be attached to the body and greater cornu of the hyoid bone; this is termed the suprahyoid aponeurosis.
Elevator Muscles of the Mandible
Medial pterygoid muscle
Origin deep head: medial side of lateral pterygoid plate behind the upper teeth superficial head: pyramidal process of palatine bone and maxillary tuberosity
Insertion medial angle of the mandible Actions elevates mandible, closes jaw, helps lateral pterygoids in moving the jaw from side to side
The medial pterygoid (or internal pterygoid muscle), is a thick, quadrilateral muscle of mastication. It consists of two heads. * The bulk of the muscle arises as a deep head from just above the medial surface of the lateral pterygoid plate. * The smaller, superficial head originates from the maxillary tuberosity and the pyramidal process of the palatine bone.
Its fibers pass downward, lateral, and posterior, and are inserted, by a strong tendinous lamina, into the lower and back part of the medial surface of the ramus and angle of the mandible, as high as the mandibular foramen. The insertion joins the masseter muscle to form a common tendinous sling which allows the medial pterygoid and masseter to be powerful elevators of the jaw.the insertion is on the anterior surface of the condyle.
Lateral pterygoid muscle
Origin Great wing of sphenoid and pterygoid plate
Insertion Condyle of mandible
Actions depresses mandible, Protrude mandible, side to side movement of mandible
The upper/superior head originates on the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, and the lower/inferior head on the lateral surface of the lateral pterygoid plate.
Inferior head inserts onto the pterygoid fovea under the condylar process of the mandible; upper/superior head inserts onto the articular disc and fibrous capsule of the TMJ.
Neck Muscles

Trapezius
Origin external occipital protuberance, nuchal ligament, medial superior nuchal line, spinous processes of vertebrae C7-T12
Insertion lateral third of clavicle, acromion process, and spine of scapula
Actions rotation, retraction, elevation, and depression of scapula
The two trapezius muscles together resemble a trapezium (trapezoid in American English), or diamond-shaped quadrilateral. The word "spinotrapezius" refers to the human trapezius, although it is not commonly used in modern texts. In other mammals, it refers to a portion of the analogous muscle. Anatomy
The trapezius arises from the external occipital protuberance and the medial third of the superior nuchal line of the occipital bone (both in the back of the head), from the ligamentum nuchae, the spinous process of the seventh cervical (both in the back of the neck), and the spinous processes of all the thoracic vertebrae, and from the corresponding portion of the supraspinal ligament (both in the upper back).
From this origin: * the superior fibers proceed downward and laterally. They are inserted into the posterior border of the lateral third of the clavicle. * the inferior fibers proceed upward and lateralward. They converge near the scapula and end in an aponeurosis, which glides over the smooth triangular surface on the medial end of the spine, to be inserted into a tubercle at the apex of this smooth triangular surface. * the middle fibers proceed horizontally. They are inserted into the medial margin of the acromion, and into the superior lip of the posterior border of the spine of the scapula.
At its occipital origin, the trapezius is connected to the bone by a thin fibrous lamina, firmly adherent to the skin. The superficial and deep epimysia are continuous with an investing deep fascia that encircles the neck and also contains both sternocleidomastoid muscles.
At the middle, the muscle is connected to the spinous processes by a broad semi-elliptical aponeurosis, which reaches from the sixth cervical to the third thoracic vertebræ and forms, with that of the opposite muscle, a tendinous ellipse. The rest of the muscle arises by numerous short tendinous fibers.

Sternocleidomastoid muscle Origin manubrium sterni, medial portion of the clavicle Insertion mastoid process of the temporal bone,
Actions Acting alone, tilts head to its own side and rotates it so the face is turned towards the opposite side. sternocleidomastoid muscle, is a paired muscle in the superficial layers of the anterior portion of the neck. It acts to flex and rotate the head.
It also acts as an accessory muscle of inspiration, along with the scalene muscles of the neck.
The sternocleidomastoid passes obliquely across the side of the neck.
It is thick and narrow at its central part, but broader and thinner at either end. * The medial or sternal head is a rounded fasciculus, tendinous in front, fleshy behind, which arises from the upper part of the anterior surface of the manubrium sterni, and is directed superiorly, laterally, and posteriorly. * The lateral or clavicular head, composed of fleshy and aponeurotic fibers, arises from the superior border and anterior surface of the medial third of the clavicle; it is directed almost vertically upward.
The two heads are separated from one another at their origins by a triangular interval, but gradually blend, below the middle of the neck, into a thick, rounded muscle which is inserted, by a strong tendon, into the lateral surface of the mastoid process, from its apex to its superior border, and by a thin aponeurosis(layers of flat broad tendons) into the lateral half of the superior nuchal line of the occipital bone.

Teres major muscle
Origin posterior aspect of the inferior angle of the scapula
Insertion medial lip of the intertubercular sulcus of the humerus Actions Internal rotation (medial rotation) of the humerus
It arises from the oval area on the dorsal surface of the inferior angle of the scapula, and from the fibrous septa interposed between the muscle and the Teres minor and Infraspinatus. The fibers of teres major insert into the medial lip of the bicipital groove of the humerus.

Teres minor muscle
Origin lateral border of the scapula
Insertion inferior facet of greater tubercle of the humerus Actions laterally rotates and adducts the arm
The Teres minor is a narrow, elongated muscle of the rotator cuff. It arises from the dorsal surface of the axillary border of the scapula for the upper two-thirds of its extent, and from two aponeurotic laminæ, one of which separates it from the Infraspinatus, the other from the Teres major. Its fibers run obliquely upward and lateralward; the upper ones end in a tendon which is inserted into the lowest of the three impressions on the greater tubercle of the humerus; the lowest fibers are inserted directly into the humerus immediately below this impression.
Sartorius muscle
Origin superior to the anterior superior iliac spine
Insertion anteromedial surface of the upper tibia in the
Actions Flexion of knee, Flexion of leg
The Sartorius muscle is a long thin muscle that runs down the length of the thigh. It is the longest muscle in the human body. Its upper portion forms the lateral border of the femoral triangle. The sartorius muscle arises by tendinous fibres from the anterior superior iliac spine, running obliquely across the upper and anterior part of the thigh in an inferomedial direction. It descends as far as the medial side of the knee, passing behind the medial condyle of the femur to end in a tendon. This tendon curves anteriorly to join the tendons of the gracilis and semitendinous muscles which together form the pes anserinus, finally inserting into the proximal part of the tibia on the medial surface of its body.
Adductor Longus – Thigh Muscle
Origin pubic body just below the pubic crest Insertion middle third of linea aspera
Actions adduction of thigh, flexion
The adductor longus muscle is a muscle of the human body. It is a part of the adductor group of the thigh, that as the name suggests adducts the thigh.
It originates on the pubic body just below the pubic crest and inserts into the middle third of linea aspera.
The adductor longus muscle forms the medial wall of the femoral triangle.

TRIANGLES

Anterior Triangle of the Neck
Boundaries of the Anterior Cervical Triangle * Medially: anterior median line of the neck. * Anteriorly: inferior border of the mandible. * Laterally: anterior border of SCM. * Its apex is at the jugular notch. * Its base is formed by the inferior border of the mandible and a line drawn from the angle of the mandible to the mastoid process. * This triangular region is used for approaching many important structures in the neck (e.g., larynx, trachea, and thyroid gland). * Using the digastric and omohyoid muscles, it is common to divide the anterior triangle into smaller submandibular, submental, carotid, and muscular triangles to descriptive purposes.

Floor of the Anterior Cervical Triangle * The floor of the anterior triangle of the neck is formed mainly by the pharynx, larynx, and thyroid gland. * Deep to these structures is the prevertebral fascia covering the prevertebral muscles. Contents of the Anterior Cervical Triangle * This triangle contains the suprahyoid and infrahyoid muscles, arteries, veins, nerves, lymph nodes, and viscera (e.g., thyroid gland).

Posterior Triangle of the Neck

Boundaries of the Posterior Cervical Triangle Anteriorly: posterior border of the sternocleidomastoid muscle. * Posteriorly: anterior border of the trapezius muscle. * Inferiorly: middle 1/3 of the clavicle. * The clavicle forms the base of the posterior triangle. * The apex is formed where the borders of the sternocleidomastoid and the trapezius muscles meet on the superior nuchal line of the occipital bone. * The occipital artery passes through the apex of the posterior triangle before it ascends over the posterior aspect of the head. Roof of the Posterior Cervical Triangle * The posterior triangle is covered by deep fascia, which covers the space between the trapezius and the sternocleidomastoid. * Superficial to the deep fascia are the superficial fascia, platysma, superficial veins, cutaneous nerves, and skin. Floor of the Posterior Cervical Triangle
Click here for a diagram of the floor of the posterior cervical triangle. * The fascial and muscular floor of this triangle is formed (superior to inferior) by the splenius capitis, levator scapulae, scalenus medius, and scalenus anterior muscles. * These muscles are covered by the prevertebral layer of deep cervical fascia. This "fascial carpet" is a lateral prolongation of the prevertebral fascia.
Femoral triangle
The femoral triangle (of Scarpa) is an anatomical region of the upper inner human thigh.
It is bounded by: * (superiorly) the inguinal ligament * (medially) the medial border of adductor longus muscle * (laterally) the medial border of sartorius muscle
Its floor is formed (medial to lateral) by adductor longus, pectineus and iliopsoas. Its roof is formed by the fascia lata.

Right Side: Right femoral sheath laid open to show its three compartments

Left side: Drawing of the left femoral triangle - shows superior portion of the femoral vein

BLOOD

Blood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells.
In vertebrates, it is composed of blood cells suspended in a liquid called blood plasma. Plasma, which comprises 55% of blood fluid, is mostly water (90% by volume), and contains dissolved proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), platelets and blood cells themselves. The blood cells present in blood are mainly red blood cells (also called RBCs or erythrocytes) and white blood cells, including leukocytes and platelets. The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion.
Blood plasma is the yellow liquid component of blood, in which the blood cells in whole blood would normally be suspended. It makes up about 55% of the total blood volume. It is mostly water (90% by volume) and contains dissolved proteins, glucose, clotting factors, mineral ions, hormones and carbon dioxide (plasma being the main medium for excretory product transportation). Blood plasma is prepared by spinning a tube of fresh blood in a centrifuge until the blood cells fall to the bottom of the tube. The blood plasma is then poured or drawn off.[1] Blood plasma has a density of approximately 1025 kg/m3, or 1.025 kg/l.[2]
Blood serum is blood plasma without fibrinogen or the other clotting factors (i.e., whole blood minus both the cells and the clotting factors).
Blood proteins, also called serum proteins, are proteins found in blood plasma. Serum total protein in blood is 7g/dl, which in total makes 7% of total blood volume. They serve many different functions, including * circulatory transport molecules for lipids, hormones, vitamins and metals * enzymes, complement components, protease inhibitors, and kinin precursors * regulation of acellular activity and functioning and in the immune system.
Separating serum proteins by electrophoresis is a valuable diagnostic tool as well as a way to monitor clinical progress.
Medical terms related to blood often begin with hemo- or hemato- (also spelled haemo- and haemato-) from the Ancient Greek word αἷμα (haima) for "blood". In terms of anatomy and histology, blood is considered a specialized form of connective tissue, given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen.

Particles of formed elements

A. The megakaryocyte is a bone marrow cell responsible for the production of blood thrombocytes (platelets), which are necessary for normal blood clotting. Megakaryocytes normally account for 1 out of 10,000 bone marrow cells but can increase in number nearly 10-fold in certain diseases. B. Erythrocytes - Red blood cells (also referred to as are the most common type of blood cell and the vertebrate body's principal means of delivering oxygen to the body tissues via the blood. They take up oxygen in the lungs or gills and release it while squeezing through the body's capillaries. The cells are filled with hemoglobin, a biomolecule that can bind to oxygen. The blood's red color is due to the color of oxygen-rich hemoglobin. In humans, red blood cells develop in the bone marrow and live for about 120 days; they take the form of flexible biconcave disks that lack a cell nucleus and organelles and they cannot synthesize protein. Red blood cells are also known as RBCs, red blood corpuscles (an archaic term), haematids or erythrocytes (from Greek erythros for "red" and kytos for "hollow", with cyte translated as "cell" in modern usage). The capitalized term Red Blood Cells is the proper name in the US for erythrocytes in storage solution used in transfusion medicine. C. White blood cells (WBCs), or leukocytes (also spelled "leucocytes"), are cells of the immune system defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a hematopoietic stem cell. Leukocytes are found throughout the body, including the blood and lymphatic system. The number of leukocytes in the blood is often an indicator of disease. There are normally between 4×109 and 1.1×1010 white blood cells in a litre of blood, making up approximately 1% of blood in a healthy adult
There are several different types of white blood cells. They all have many things in common, but are all different. A major distinguishing feature of some leukocytes is the presence of granules; white blood cells are often characterized as granulocytes or agranulocytes:
Granulocytes (polymorphonuclear leukocytes): leukocytes characterised by the presence of differently staining granules in their cytoplasm when viewed under light microscopy. These granules are membrane-bound enzymes which primarily act in the digestion of endocytosed particles. There are three types of granulocytes: neutrophils, basophils, and eosinophils, which are named according to their staining properties.
Neutrophil- -Neutrophils defend against bacterial or fungal infection and other very small inflammatory processes that are usually first responders to microbial infection; their activity and death in large numbers forms pus. They are commonly referred to as polymorphonuclear (PMN) leukocytes, although technically PMN refers to all granulocytes. They have a multilobed nucleus which may appear like multiple nuclei, hence the name polymorphonuclear leukocyte. The cytoplasm may look transparent because of fine granules that are faintly pink. Neutrophils are very active in phagocytosing bacteria and are present in large amount in the pus of wounds. These cells are not able to renew their lysosomes used in digesting microbes and die after having phagocytosed a few pathogens.[citation needed]
Eosinophil - Eosinophils primarily deal with parasitic infections and an increase in them may indicate such. Eosinophils are also the predominant inflammatory cells in allergic reactions. The most important causes of eosinophilia include allergies such as asthma, hay fever, and hives; and also parasitic infections. Generally their nucleus is bi-lobed. The cytoplasm is full of granules which assume a characteristic pink-orange color with eosin stain.
Basophil - Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine causing inflammation. The nucleus is bi- or tri-lobed, but it is hard to see because of the number of coarse granules which hide it. They are characterized by their large blue granules.
Agranulocytes (mononuclear leucocytes): leukocytes characterized by the apparent absence of granules in their cytoplasm. Although the name implies a lack of granules these cells do contain non-specific azurophilic granules, which are lysosomes[4]. The cells include lymphocytes, monocytes, and macrophages.[
Monocyte - Monocytes share the "vacuum cleaner" (phagocytosis) function of neutrophils, but are much longer lived as they have an additional role: they present pieces of pathogens to T cells so that the pathogens may be recognized again and killed, or so that an antibody response may be mounted. Monocytes eventually leave the bloodstream to become tissue macrophages which remove dead cell debris as well as attacking microorganisms. Neither of these can be dealt with effectively by the neutrophils. Unlike neutrophils, monocytes are able to replace their lysosomal contents and are thought to have a much longer active life. They have the kidney shaped nucleus and are typically agranulated. They also possess abundant cytoplasm.
Once monocytes move from the bloodstream out into the body tissues, they undergo changes (differentiate) allowing phagocytosis and are then known as macrophages.
Lymphocyte - Lymphocytes are much more common in the lymphatic system. Lymphocytes are distinguished by having a deeply staining nucleus which may be eccentric in location, and a relatively small amount of cytoplasm. The blood has three types of lymphocytes: * B cells: B cells make antibodies that bind to pathogens to enable their destruction. (B cells not only make antibodies that bind to pathogens, but after an attack, some B cells will retain the ability to produce an antibody to serve as a 'memory' system.) * T cells: * CD4+ (helper) T cells co-ordinate the immune response and are important in the defense against intracellular bacteria. In acute HIV infection, these T cells are the main index to identify the individual's immune system activity. Research has shown [9] that CD8+ cells are also another index to identify human's immune activity. * CD8+ cytotoxic T cells are able to kill virus-infected and tumor cells. * Gamma delta T cells possess an alternative T cell receptor as opposed to CD4+ and CD8+ αβ T cells and share characteristics of helper T cells, cytotoxic T cells and natural killer cells. * Natural killer cells: Natural killer cells are able to kill cells of the body which are displaying a signal to kill them, as they have been infected by a virus or have become cancerous.
Interferons (IFNs) are natural cell-signaling proteins produced by the cells of the immune system of most vertebrates in response to challenges such as viruses, parasites and tumor cells. They belong to the large class of glycoproteins known as cytokines and are produced by a wide variety of cells in response to the presence of double-stranded RNA, a key indicator of viral infection. Interferons assist the immune response by inhibiting viral replication within host cells, activating natural killer cells and macrophages, increasing antigen presentation to T lymphocytes, and increasing the resistance of host cells to viral infection. There are 3 known classes of interferons; type I, type II and type III. All classes are very important in fighting viral infections. Their presence also accounts for some of the host symptoms to infections, such as sore muscles and fever.

The major histocompatibility complex (MHC) is a large genomic region or gene family found in most vertebrates. It is the most gene-dense region of the mammalian genome and plays an important role in the immune system and autoimmunity. The diversity of MHC is important in the immune diversity in the population. The proteins encoded by the MHC are expressed on the surface of cells in all jawed vertebrates, and display both self antigens (peptide fragments from the cell itself) and nonself antigens (e.g., fragments of invading microorganisms) to a type of white blood cell called a T cell that has the capacity to kill or co-ordinate the killing of pathogens and infected or malfunctioning cells.

There are two primary classes of major histocompatibility complex (MHC) molecules, MHC class I and MHC class II. MHC class I molecules are found on every nucleated cell of the body (and thus not on red blood cells). Their function is to display fragments of proteins from within the cell to T cells, so that healthy cells will be left alone and cells with foreign proteins will be attacked by the immune system. Because MHC class I molecules present peptides derived from cytosolic proteins, the pathway of MHC class I presentation is often called the cytosolic or endogenous pathway.

ABO
Blood Type | Per Cent of General Population | Can
DONATE
Red Cells To: | Can
RECEIVE
Red Cells From: | Chance of FindingA Compatible Donor | O+ | 38.5% | O+, A+, B+, AB+ | O+, O- | 1 out of 2 - 50% | O- | 6.5% | All Types
(universal donor) | O- | 1 out of 15 - 7% | A+ | 34.3% | A+, AB+ | A+, A-, O+, O- | 4 out of 5 - 80% | A- | 5.7% | A-, A+, AB-, AB+ | A-, O- | 1 out of 8 - 13% | B+ | 8.6% | B+, AB+ | B+, B-, O+, O- | 3 out of 5 - 60% | B- | 1.7% | B-, B+, AB-, AB+ | B-, O- | 1 out of 12 - 9% | AB+ | 4.3% | AB+ | All Types
(universal recipient) | 100% | AB- | 0.7% | AB-, AB+ | AB-, A-, B-, O- | 1 out of 7 - 14% | | | | | |

Rh Factor
Rh blood types were discovered in 1940 by Karl Landsteiner and Alexander Wiener. This was 40 years after Landsteiner had discovered the ABO blood groups. Over the last half century, we have learned far more about the processes responsible for Rh types. This blood group may be the most complex genetically of all blood type systems since it involves 45 different antigens on the surface of red cells that are controlled by 2 closely linked genes on chromosome 1.
The Rh system was named after rhesus monkeys, since they were initially used in the research to make the antiserum for typing blood samples. If the antiserum agglutinates your red cells, you are Rh+ If it doesn't, you are Rh-. Despite its actual genetic complexity, the inheritance of this trait usually can be predicted by a simple conceptual model in which there are two alleles, D and d. Individuals who are homozygous dominant (DD) or heterozygous (Dd) are Rh+. Those who are homozygous recessive (dd) are Rh- (i.e., they do not have the key Rh antigens).
Clinically, the Rh factor, like ABO factors, can lead to serious medical complications. The greatest problem with the Rh group is not so much incompatibilities following transfusions (though they can occur) as those between a mother and her developing fetus.
Mother-fetus incompatibility occurs when the mother is Rh- (dd) and the father is Rh+ (DD or Dd). Maternal antibodies can cross the placenta and destroy fetal red blood cells. The risk increases with each pregnancy. Europeans are the most likely to have this problem--13% of their newborn babies are at risk. Actually only about ½ of these babies (6% of all European births) have complications. With preventive treatment, this number can be cut down even further. Less than 1% of those treated have trouble. However, Rh blood type incompatibility is still the leading cause of potentially fatal blood related problems of the newborn. In the United States, 1 out of 1000 babies are born with this condition.
Rh type mother-fetus incompatibility occurs only when an Rh+ man fathers a child with an Rh- mother. Since an Rh+ father can have either a DD or Dd genotype, there are 2 mating combinations possible:

Only the Rh+ children (Dd) are likely to have medical complications. When both the mother and her fetus are Rh- (dd), the birth will be normal.
The first time an Rh- woman becomes pregnant, there usually are not incompatibility difficulties for her Rh+ fetus. However, the second and subsequent births are likely to have life-threatening problems. The risk increases with each birth. In order to understand why first born are normally safe and later | | | Human fetus in a mother's uterus
(the umbilical cord and placenta connect the fetus to its mother) | children are not, it is necessary to understand some of the placenta's functions. Nutrients and the mother's antibodies regularly transfer across the placental boundary into the fetus, but her red blood cells usually do not (except in the case of an accidental rupture). Normally, anti-Rh+ antibodies do not exist in the first-time mother unless she has previously come in contact with Rh+ blood. Therefore, her antibodies are not likely to agglutinate the red blood cells of her Rh+ fetus.
Placental ruptures do occur normally at birth so that some fetal blood gets into the mother's system, stimulating the development of antibodies to Rh+ blood antigens. As little as one drop of fetal blood stimulates the production of large amounts of antibodies. When the next pregnancy occurs, a transfer of antibodies from the mother's system once again takes place across the placental boundary into the fetus. The anti-Rh+ antibodies that she now produces react with the fetal blood, causing many of its red cells to burst or agglutinate. As a result, the newborn baby may have a life-threatening anemia because of a lack of oxygen in the blood. The baby also usually is jaundiced, fevered, quite swollen, and has an enlarged liver and spleen. This condition is called erythroblastosis fetalis The standard treatment in severe cases is immediate massive transfusions of Rh- blood into the baby with the simultaneous draining of the existing blood to flush out Rh+ antibodies from the mother. This is usually done immediately following birth, but it can be done to a fetus prior to birth. Later, the Rh- blood will be replaced naturally as the baby gradually produces its own Rh+ blood. Any residual anti-Rh+ antibodies from the mother will leave gradually as well because the baby does not produce them.
Erythroblastosis fetalis can be prevented for women at high risk (i.e., Rh- women with Rh+ mates or mates whose blood type is unknown) by administering a serum (Rho-GAM) containing anti-Rh+ antibodies into the mother around the 28th week of pregnancy and again within 72 hours after the delivery of an Rh+ baby. This must be done for the first and all subsequent pregnancies. The injected antibodies quickly agglutinate any fetal red cells as they enter the mother's blood, thereby preventing her from forming her own antibodies. The serum provides only a passive form of immunization and will shortly leave her blood stream. Therefore, she does not produce any long-lasting antibodies. This treatment can be 99% effective in preventing erythroblastosis fetalis. Rho-GAM is also routinely given to Rh- women after a miscarriage, an ectopic pregnancy, or an induced abortion. Without the use of Rho-GAM, an Rh- woman is likely to produce larger amounts of Rh+ antibodies every time she becomes pregnant with an Rh+ baby because she is liable to come in contact with more Rh+ blood. Therefore, the risk of life-threatening erythroblastosis fetalis increases with each subsequent pregnancy.
Anti-Rh+ antibodies may be produced in an individual with Rh- blood as a result of receiving a mismatched blood transfusion. When this occurs, there is likely to be production of the antibodies throughout life. Once again, Rho-GAM can prevent this from happening.
Mother-fetus incompatibility problems can result with the ABO system also. However, they are very rare--less than .1% of births are affected and usually the symptoms are not as severe. It most commonly occurs when the mother is type O and her fetus is A, B, or AB. The symptoms in newborn babies are usually jaundice, mild anemia, and elevated bilirubin levels. These problems in a baby are usually treated successfully without blood transfusions.
Blood Clotting Factors (Coagulation)
Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis (the cessation of blood loss from a damaged vessel), wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel. Disorders of coagulation can lead to an increased risk of bleeding (hemorrhage) or clotting (thrombosis).
Coagulation is highly conserved throughout biology; in all mammals, coagulation involves both a cellular (platelet) and a protein (coagulation factor) component. The system in humans has been the most extensively researched and, therefore, the best-understood.
Coagulation begins almost instantly after an injury to the blood vessel has damaged the endothelium (lining of the vessel), this releases phospholipid components called tissue thromboplastin that initiate a chain reaction. Platelets immediately form a plug at the site of injury; this is called primary hemostasis. Secondary hemostasis occurs simultaneously: Proteins in the blood plasma, called coagulation factors or clotting factors, respond in a complex cascade to form fibrin strands, which strengthen the platelet plug. coagulation factor - one of 13 factors in the blood, the interactions of which are responsible for the process of blood clotting. The factors, using standardized numeric nomenclature, are factor I, fibrinogen; factor II, prothrombin; factor III, tissue thromboplastin; factor IV, calcium ions; factors V and VI, proaccelerin or labile factor; factor VII, proconvertin or stable factor; factor VIII, antihemophilic globulin; factor IX, plasma thromboplastin component; factor X, Stuart-Power factor; factor XI, plasma thromboplastin antecedent; factor XII, Hageman factor or glass factor or contact factor; factor XIII, fibrin stabilizing factor or fibrinase or Laki-Lorand factor. See also blood clotting, coagulation, fibrinogen, hemophilia A, hemophilia B, hemophilia C, factor II through factor XIII.
What are rare clotting factor deficiencies?
If any of the clotting factors is missing or is not working properly, the chain reaction is blocked. When this happens, the blood clot does not form and the bleeding continues longer than it should.
Deficiencies of factor VIII and factor IX are known as hemophilia A and B, respectively. Rare clotting factor deficiencies are bleeding disorders in which one of the other clotting factors (i.e. factors I, II, V, VII, X, XI, or XIII) is missing or not working properly. Less is known about these disorders because they are diagnosed so rarely. In fact, many have only been discovered in the last 40 years.

Cardiovascular system PART 1 (missing)
Cardiovascular System Part 2
A drop of blood through the heart : Deoxygenated blood from the body enters the right atrium. It flows through the tricuspid valve into the right ventricle. Contraction of the ventricle then closes the tricuspid valve and forces open the pulmonary valve. Blood flows into the pulmonary artery. This branches immediately, carrying blood to the right and left lungs. Here the blood gives up carbon dioxide and takes on a fresh supply of oxygen. The capillary beds of the lungs are drained by venules that are the tributaries of the pulmonary veins. Four pulmonary veins, two draining each lung, carry oxygenated blood to the left atrium of the heart From the left atrium, Blood flows through the mitral valve into the left ventricle. Contraction of the ventricle closes the mitral valve and opens the aortic valve at the entrance to the aorta. The first branches from the aorta occur just beyond the aortic valve still within the heart. Two openings lead to the right and left coronary arteries, which supply blood to the heart itself.
The descending aorta is part of the aorta, the largest artery in the body. The descending aorta is the part of the aorta beginning at the aortic arch that runs down through the chest and abdomen. The descending aorta is divided into two portions, the thoracic and abdominal, in correspondence with the two great cavities of the trunk in which it is situated. Within the abdomen, the descending aorta branches into the two common iliac arteries which serve the legs.

The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of descending aorta(of the thorax).
Path
It begins at the level of the diaphragm, crossing it via the aortic hiatus, technically BEHIND the diaphragm, at the vertebral level of T12. It travels down the posterior wall of the abdomen in front of the vertebral column. It thus follows the curvature of the lumbar vertebrae, that is, convex anteriorly. The peak of this convexity is at the level of the third lumbar vertebra (L3).
It runs parallel to the inferior vena cava, which is located just to the right of the abdominal aorta, and becomes smaller in diameter as it gives off branches. This is thought to be due to the large size of its principal branches. At the 11th rib, the diameter is about 25 mm; above the origin of the renal arteries, 22 mm; below the renals, 20 mm; and at the bifurcation, 19 mm.
Branches

The celiac artery, also known as the celiac trunk, is the first major branch of the abdominal aorta. Branching from the aorta 'anterior to the upper part of L1' vertebra in humans, it is one of three anterior/ midline branches of the abdominal aorta (the others are the superior and inferior mesenteric arteries).
The common hepatic artery is a short blood vessel that supplies oxygenated blood to the liver, pylorus (a part of the stomach), duodenum (a part of the small intestine) and pancreas. left gastric artery arises from the celiac artery, and runs along the superior portion of the lesser curvature of the stomach. Branches also supply the lower esophagus. The left gastric artery anastomoses with the right gastric artery, which supplies the inferior portion.

right gastric artery (pyloric artery) arises from the common hepatic artery, above the pylorus, descends to the pyloric end of the stomach, and passes from right to left along its lesser curvature, supplying it with branches, and anastomosing with the left gastric artery.

Gastroepiploic artery is the name of two different arteries serving the stomach and greater omentum: * Left gastro-omental artery, a branch of the splenic artery * Right gastro-omental artery, a branch of the gastroduodenal artery
Splenic artery is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas.

the superior mesenteric artery (SMA) arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas.

renal arteries normally arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle with the aorta.
The renal arteries carry a large portion of total blood flow to the kidneys. Up to a third of total cardiac output can pass through the renal arteries to be filtered by the kidneys.
The arterial supply of the kidneys is variable and there may be one or more renal arteries supplying each kidney. It is located above the renal vein.
The term gonadal artery is a generic term for a paired artery, with one arising from the abdominal aorta for each gonad. Specifically, it can refer to: testicular artery (the male gonadal artery, also called the internal spermatic arteries in older texts) is a branch of the abdominal aorta that supplies blood to the testis. It is a paired artery, with one for each of the testes. It is the male equivalent of the ovarian artery. Because the testis is found in a different location than that of its female equivalent, it has a different course than the ovarian artery. ovarian artery is a blood vessel that supplies oxygenated blood to the ovary. It arises from the abdominal aorta below the renal artery, and does not pass out of the abdominal cavity. It can be found in the suspensory ligament of the ovary. the inferior mesenteric artery, often abbreviated as IMA, supplies the large intestine from the left colic (or splenic) flexure to the upper part of the rectum, which includes the descending colon, the sigmoid colon, and part of the rectum.
POSTERIOR BRANCHES
The inferior phrenic arteries are two small vessels, which supply the diaphragm but present much variety in their origin.
They may arise separately from the front of the aorta, immediately above the celiac artery, or by a common trunk, which may spring either from the aorta or from the celiac artery. Sometimes one is derived from the aorta, and the other from one of the renal arteries; they rarely arise as separate vessels from the aorta.
The lumbar arteries are in series with the intercostals.
They are usually four in number on either side, and arise from the back of the aorta, opposite the bodies of the upper four lumbar vertebræ.
A fifth pair, small in size, is occasionally present: they arise from the middle sacral artery.
They run lateral and backward on the bodies of the lumbar vertebræ, behind the sympathetic trunk, to the intervals between the adjacent transverse processes, and are then continued into the abdominal wall.
The arteries of the right side pass behind the inferior vena cava, and the upper two on each side run behind the corresponding crus of the diaphragm. common iliac arteries are two large arteries, about 4cm long in adults but more than a centimetre in diameter, that originate from the aortic bifurcation. The arteries run inferolaterally, along the medial border of the psoas muscles to the pelvic brim, where they bifurcate into the external iliac artery and internal iliac artery. The common iliac artery, and all of its branches, exist as paired structures (that is to say, there is one on the left side and one on the right).
The distribution of the common iliac artery is basically the pelvis and lower limb (as the femoral artery) on the corresponding side.
Both common iliac arteries are accompanied along their course by common iliac veins.

internal iliac artery (formerly known as the hypogastric artery) is the main artery of the pelvis. The internal iliac artery supplies the walls and viscera of the pelvis, the buttock, the reproductive organs, and the medial compartment of the thigh.
It is a short, thick vessel, smaller than the external iliac artery, and about 3 to 4 cm in length. internal pudendal artery is an artery that branches off the internal iliac artery, providing blood to the external genitalia. The internal pudendal artery is the terminal branch of the anterior trunk of the internal iliac artery. It is smaller in the female than in the male. It exits the pelvic cavity through the greater sciatic foramen to enter the gluteal region. It then curves around the sacrospinous ligament to enter the perineum through the lesser sciatic foramen. It travels through the pudendal canal with the internal pudendal veins and the pudendal nerve.
The external iliac artery is a large artery in the pelvic region that carries blood to the lower limb. The external iliac artery is a paired artery, meaning there is one on each side of the body: a right external iliac artery and left external iliac artery. The external iliac artery is accompanied by the external iliac vein, which is located posterior to the artery. femoral artery is a large artery in the muscles of the thigh. It is a continuation of external iliac artery where it enters the femoral triangle at the mid inguinal point behind the inguinal ligament. It leaves femoral triangle through apex beneath the sartorius muscle. It enters the popliteal fossa by passing through the 5th osseo-aponeurotic(adductor hiatus) opening of adductor magnus where it becomes the Popliteal artery. the popliteal artery is defined as the extension of the "superficial" femoral artery after passing through the adductor canal and adductor hiatus above the knee. The termination of the popliteal artery is its bifurcation into the anterior tibial artery and posterior tibial artery.
The popliteal artery, through numerous smaller branches, supplies blood to the knee joint and muscles in the thigh and calf. It is accompanied, along its length, by the popliteal vein. anterior tibial artery of the lower limb carries blood to the anterior compartment of the leg and dorsal surface of the foot, from the popliteal artery. It is accompanied by a deep vein, the anterior tibial vein, along its course. It crosses the anterior aspect of the ankle joint, at which point it becomes the dorsalis pedis artery. posterior tibial artery of the lower limb carries blood to the posterior compartment of the leg and plantar surface of the foot, from the popliteal artery. It is accompanied by a deep vein, the posterior tibial vein, along its course. fibular artery (also known as the peroneal artery) supplies blood to the lateral compartment of the leg and is typically a branch of posterior tibial artery. medial plantar artery (internal plantar artery), much smaller than the lateral, passes forward along the medial side of the foot. It is at first situated above the Abductor hallucis, and then between it and the Flexor digitorum brevis, both of which it supplies. At the base of the first metatarsal bone, where it is much diminished in size, it passes along the medial border of the first toe, anastomosing with the first dorsal metatarsal artery. lateral plantar artery (external plantar artery), much larger than the medial, passes obliquely lateralward and forward to the base of the fifth metatarsal bone. It then turns medialward to the interval between the bases of the first and second metatarsal bones, where it unites with the deep plantar branch of the dorsalis pedis artery, thus completing the plantar arch. As this artery passes lateralward, it is first placed between the calcaneus and Abductor hallucis, and then between the Flexor digitorum brevis and Quadratus plantæ as it runs forward to the base of the little toe it lies more superficially between the Flexor digitorum brevis and Abductor digiti quinti, covered by the plantar aponeurosis and integument. The remaining portion of the vessel is deeply situated; it extends from the base of the fifth metatarsal bone to the proximal part of the first interosseous space, and forms the plantar arch; it is convex forward, lies below the bases of the second, third, and fourth metatarsal bones and the corresponding Interossei, and upon the oblique part of the Adductor hallucis dorsalis pedis artery (dorsal artery of foot), is a blood vessel of the lower limb that carries oxygenated blood to the dorsal surface of the foot. It arises at the anterior aspect of the ankle joint and is a continuation of the anterior tibial artery. It terminates at the proximal part of the first intermetatarsal space, where it divides into two branches, the first dorsal metatarsal artery and the deep plantar artery.
VEINS (drainage)

posterior tibial vein of the lower limb carries blood from the posterior compartment and plantar surface of the foot to the popliteal vein which it forms when it joins with the anterior tibial vein. Like most deep veins, the posterior tibial vein is accompanied by an artery of the same name, the posterior tibial artery, along its course. the anterior tibial vein of the lower limb carries blood from the anterior compartment of the leg to the popliteal vein which is forms when it joins with the posterior tibial vein. Like most deep veins, the anterior tibial vein is accompanied by an artery of the same name, the anterior tibial artery, along its course. opliteal vein course runs alongside the popliteal artery but carries the blood from the knee joint and muscles in the thigh and calf back to the heart. Its origin is defined by the junction of the posterior tibial vein and anterior tibial vein. It drains the peroneal vein before reaching the knee joint and turns into the femoral vein when leaving the adductor canal (also known as Hunter's canal). The popliteal artery extends from the femoral artery behind the popliteal fossa which is the space behind the knee. great saphenous vein (GSV), also greater saphenous vein, is the large (subcutaneous) superficial vein of the leg and thigh. femoral artery is a large artery in the muscles of the thigh. It is a continuation of external iliac artery where it enters the femoral triangle at the mid inguinal point behind the inguinal ligament. It leaves femoral triangle through apex beneath the sartorius muscle. It enters the popliteal fossa by passing through the 5th osseo-aponeurotic(adductor hiatus) opening of adductor magnus where it becomes the Popliteal artery. internal iliac vein (hypogastric vein) begins near the upper part of the greater sciatic foramen, passes upward behind and slightly medial to the hypogastric artery and, at the brim of the pelvis, joins with the external iliac to form the common iliac vein. the common iliac veins are formed by the external iliac veins and internal iliac veins and together, in the abdomen at the level of the fifth lumbar vertebrae[1], form the inferior vena cava. They drain blood from the pelvis and lower limbs.
Both common iliac veins are accompanied along their course by common iliac arteries. inferior vena cava (or IVC) is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart.
It is posterior to the abdominal cavity and runs alongside of the vertebral column on its right side (i.e. it is a retroperitoneal structure). It enters the right atrium at the lower right, back side of the heart.
Inferior Phrenic Veins drain the diaphragm and follow the course of the inferior phrenic arteries the hepatic veins are the blood vessels that drain de-oxygenated blood from the liver and blood cleaned by the liver (from the stomach, pancreas, small intestine and colon) into the inferior vena cava.
They arise from the substance of the liver, more specifically the central vein of the liver lobule. None of the hepatic veins have valves.
Suprarenal veins are two in number: * the right ends in the inferior vena cava. * the left ends in the left renal or left inferior phrenic vein.
They receive blood from the adrenal glands and will sometimes form anastomoses with the inferior phrenic veins. renal veins are veins that drain the kidney. They connect the kidney to the inferior vena cava.
It is usually singular to each kidney, except in the condition "multiple renal veins".[1]
It also divides into 2 divisions upon entering the kidney: * the anterior branch which receives blood from the anterior portion of the kidney and, * the posterior branch which receives blood from the posterior portion.
Often, each renal vein will have a branch that receives blood from the ureter. gonadal vein refers to the blood vessel that carrying blood away from the gonad (testis, ovary) toward the heart. testicular vein (or spermatic vein), the male gonadal vein, carries deoxygenated blood from its corresponding testis to the inferior vena cava or one of its tributaries. It is the male equivalent of the ovarian vein, and is the venous counterpart of the testicular artery.
It is a paired vein, with one supplying each testis: * the right testicular vein generally joins the inferior vena cava; * the left testicular vein, unlike the right, often joins the left renal vein instead of the inferior vena cava.
The veins emerge from the back of the testis, and receive tributaries from the epididymis; they unite and form a convoluted plexus, called the pampiniform plexus, which constitutes the greater mass of the spermatic cord; the vessels composing this plexus are very numerous, and ascend along the cord, in front of the ductus deferens. Below the subcutaneous inguinal ring, they unite to form three or four veins, which pass along the inguinal canal, and, entering the abdomen through the abdominal inguinal ring, coalesce to form two veins, which ascend on the Psoas major, behind the peritoneum, lying one on either side of the internal spermatic artery. These unite to form a single vein, which opens, on the right side, into the inferior vena cava (at an acute angle), on the left side into the left renal vein (at a right angle). The spermatic veins are provided with valves. The left spermatic vein passes behind the iliac colon and is thus exposed to pressure from the contents of that part of the bowel. ovarian vein, the female gonadal vein, carries deoxygenated blood from its corresponding ovary to inferior vena cava or one of its tributaries. It is the female equivalent of the testicular vein, and is the venous counterpart of the ovarian artery. It can be found in the suspensory ligament of the ovary.
It a paired vein, with one supplying each ovary. * The right ovarian vein travels through the suspensatory ligament of the ovary and generally joins the inferior vena cava. * The left ovarian vein, unlike the right, often joins the left renal vein instead of the inferior vena cava. lumbar veins are veins running along the inside of the posterior abdominal wall. They are the lumbar equivalent of the posterior intercostal veins. ascending lumbar vein is a vein that runs up through the lumbar region on the side of the vertebral column. ascending lumbar vein is a paired structure (i.e. one each for the right and left sides of the body). It starts at the lateral sacral veins, and it runs superiorly, intersecting with the lumbar veins as it crosses them.
When the ascending lumbar vein crosses the subcostal vein, it becomes one of the following: * the azygos vein (in the case of the right ascending lumbar vein) * the hemiazygos vein (in the case of the left ascending lumbar vein) azygos vein is a vein running up the right side of the thoracic vertebral column. It can also provide an alternate path for blood to the superior vena cava. azygos vein transports deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava vein. The anatomy of this blood vessel can be quite variable. In some rare variations for example, it also drains thoracic veins, bronchial veins and even gonadal veins. The vein is so named because it has no symmetrically equivalent vein on the left side of the body.
It is formed by the union of the ascending lumbar veins with the right subcostal veins at the level of the 12th thoracic vertebra, ascending in the posterior mediastinum, and arching over the right main bronchus posteriorly at the root of the right lung to join the superior vena cava. This "arch of the azygos vein" (arcus venae azygou) is an important anatomic landmark. As a rare anatomical variation, the arch can be displaced laterally, thereby creating a pleural septum separating an azygos lobe from the upper lobe of the right lung.
A major tributary is the hemiazygos vein, a similar structure on the opposite side of the vertebral column. Other tributaries include the bronchial veins, pericardial veins, and posterior right intercostal veins. It communicates with the vertebral venous plexuses.
Azygos venous system
The azygos system of veins is considered to be the azygos vein, along with its left-sided counterparts, the hemiazygos vein and the accessory hemiazygos vein. Together, they form an anastomosis between the superior vena cava to the inferior vena cava.
It can be noted that the azygos system of veins exists because the superior vena cava and the inferior vena cava are not continuous. While the aorta travels downward (continuously) through the mediastinum, supplying blood to the intercostal spaces, the vena cava does not exist at the level of the heart. Thus, the azygos venous system makes up for this deficiency of the venae cavae. hemiazygos vein (vena azygos minor inferior) is a vein running superiorly in the lower thoracic region, just to the left side of the vertebral column.
The hemiazygos vein and the accessory hemiazygos vein, when taken together, essentially serve as the left-sided equivalent of the azygos vein. That is, the azygos vein serves to drain most of the posterior intercostal veins on the right side of the body, and the hemiazygos vein and the accessory hemiazygos vein drain most of the posterior intercostal veins on the left side of the body. Specifically, the hemiazygos vein mirrors the bottom part of the azygos vein.
The structure of the hemiazygos vein is often variable. It usually begins in the left ascending lumbar vein or renal vein, and passes upward through the left crus of the diaphragm to enter the thorax. It continues ascending on the left side of the vertebral column, and around the level of the ninth thoracic vertebra, it passes rightward across the column, behind the aorta, esophagus, and thoracic duct, to end in the azygos vein.
The hemiazygos may or may not be continuous superiorly with the accessory hemiazygos vein.
It receives the 9th, 10th, and 11th posterior intercostal veins and the subcostal vein of the left side, and some esophageal and mediastinal veins. the hepatic veins are the blood vessels that drain de-oxygenated blood from the liver and blood cleaned by the liver (from the stomach, pancreas, small intestine and colon) into the inferior vena cava.
They arise from the substance of the liver, more specifically the central vein of the liver lobule. None of the hepatic veins have valves.

the hepatic portal system is the system of veins comprised of the hepatic portal vein and its tributaries. It is also called the portal venous system, although it is not the only example of a portal venous system, and splanchnic veins, which is not synonymous with hepatic portal system and is imprecise (as it means visceral veins and not necessarily the veins of the abdominal viscera)
The portal venous system is responsible for directing blood from parts of the gastrointestinal tract to the liver. Substances absorbed in the small intestine travel first to the liver for processing before continuing to the heart. Not all of the gastrointestinal tract is part of this system. The system extends from about the lower portion of the esophagus to the upper part of the anal canal. It also includes venous drainage from the spleen and pancreas.
Many drugs that are absorbed through the GI tract are substantially metabolized by the liver before reaching general circulation. This is known as the first pass effect. As a consequence, certain drugs can only be taken via certain routes. For example, nitroglycerin cannot be swallowed because the liver would inactivate the medication, but it can be taken under the tongue or transdermal (through the skin) and thus is absorbed in a way that bypasses the portal venous system.
Blood flow to the liver is unique in that it receives both oxygenated and deoxygenated blood. As a result, the partial pressure of oxygen (pO2) and perfusion pressure of portal blood are lower than in other organs of the body. Blood passes from branches of the portal vein through cavities between "plates" of hepatocytes called sinusoids. Blood also flows from branches of the hepatic artery and mixes in the sinusoids to supply the hepatocytes with oxygen. This mixture percolates through the sinusoids and collects in a central vein which drains into the hepatic vein. The hepatic vein subsequently drains into the inferior vena cava.
ARTERIES OF THE ARM
Subclavian artery is a major artery of the upper thorax that mainly supplies blood to the head and arms. It is located below the clavicle, hence the name. There is a left subclavian and a right subclavian. * On the left side of the body, the subclavian comes directly off the arch of aorta. * On the right side of the body, the subclavian arises from the relatively short brachiocephalic artery (trunk) when it bifurcates into the subclavian and the right common carotid artery.
The usual branches of the subclavian on both sides of the body are the vertebral artery, the internal thoracic artery, the thyrocervical trunk, the costocervical trunk and the dorsal scapular artery. The subclavian becomes the axillary artery at the lateral border of the first rib.
Axillary artery is a large blood vessel that conveys oxygenated blood to the lateral aspect of the thorax, the axilla (armpit) and the upper limb. Its origin is at the lateral margin of the first rib, before which it is called the subclavian artery. After passing the lower margin of teres major it becomes the brachial artery
Brachial artery is the major blood vessel of the (upper) arm.
It is the continuation of the axillary artery beyond the lower margin of teres major muscle. It continues down the ventral surface of the arm until it reaches the cubital fossa at the elbow. It then divides into the radial and ulnar arteries which run down the forearm. In some individuals, the bifurcation occurs much earlier and the ulnar and radial arteries extend through the upper arm. radial artery is the main blood vessel, with oxygenated blood, of the lateral aspect of the forearm. The radial artery arises from the bifurcation of the brachial artery in the cubital fossa. It runs distally on the anterior part of the forearm. There, it serves as a landmark for the division between the anterior and posterior compartments of the forearm, with the posterior compartment beginning just lateral to the artery. The artery winds laterally around the wrist, passing through the anatomical snuff box and between the heads of the first dorsal interosseous muscle. It passes anteriorly between the heads of the adductor pollicis, and becomes the deep palmar arch, which joins with the deep branch of the ulnar artery.
Ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspect of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery. It is palpable on the anterior and medial aspect of the wrist. Along its course, it is accompanied by a similarly named vein or veins, the ulnar vein or ulnar veins. The ulnar artery, the larger of the two terminal branches of the brachial, begins a little below the bend of the elbow in the cubital fossa, and, passing obliquely downward, reaches the ulnar side of the forearm at a point about midway between the elbow and the wrist. It then runs along the ulnar border to the wrist, crosses the transverse carpal ligament on the radial side of the pisiform bone, and immediately beyond this bone divides into two branches, which enter into the formation of the superficial and deep volar arches
Ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspect of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery. It is palpable on the anterior and medial aspect of the wrist. deep palmar arch (deep volar arch) is an arterial network found in the palm. It is usually formed mainly from the terminal part of the radial artery, with the ulnar artery contributing via its deep palmar branch. This is in contrast to the superficial palmar arch, which is formed predominantly by the ulnar artery.
The deep palmar arch lies upon the bases of the metacarpal bones and on the interossei of the hand, being covered by the oblique head of the adductor pollicis muscle, the flexor tendons of the fingers, and the lumbricals of the hand.
Alongside of it, but running in the opposite direction—that is to say, toward the radial side of the hand—is the deep branch of the ulnar nerve. superficial palmar arch is formed predominantly by the ulnar artery, with a contribution from the superficial palmar branch of the radial artery. However, in some individuals the contribution from the radial artery might be absent, and instead anastomoses with either the princeps pollicis artery, the radialis indeces artery, or the median artery, the former two of which are branches from the radial artery.
VEINS OF THE ARM
Dorsal digital veins of the hand pass along the sides of the fingers and are joined to one another by oblique communicating branches. Those from the adjacent sides of the fingers unite to form three dorsal metacarpal veins.

Cephalic vein (or antecubital vein) is a superficial vein of the upper limb.
It communicates with the basilic vein via the median cubital vein at the elbow and is located in the superficial fascia along the anterolateral surface of the biceps brachii muscle. Superiorly the cephalic vein passes between the deltoid and pectoralis major muscles (deltopectoral groove) and through the deltopectoral triangle, where it empties into the axillary vein. It is often visible through the skin, and its location in the deltopectoral groove is fairly consistent, making this site a good candidate for cannulation. It is often referred to as the 'House-man's Friend' for this reason and is generally a good place for cannulaton when a large bore cannula needs to be sited.

Ulnar veins are venae comitantes for the ulnar artery. They mostly drain the medial aspect of the forearm. They arise in the hand and terminate when they join the radial veins to form the brachial veins.

radial veins are venae comitantes that accompany the radial artery through the back of the hand and the lateral aspect of the forearm. They join the ulnar veins to form the brachial veins.

axillary vein is a large blood vessel that conveys blood from the lateral aspect of the thorax, axilla (armpit) and upper limb toward the heart. There is one axillary vein on each side of the body. Its origin is at the lower margin of the teres major muscle and a continuation of the brachial vein. Its tributaries include the basilic vein and cephalic vein, which are both superficial veins. It terminates at the lateral margin of the first rib, at which it becomes the subclavian vein. basilic vein is a large superficial vein of the upper limb that helps drain parts of hand and forearm. It originates on the medial (ulnar) side of the dorsal venous network of the hand, and it travels up the base of the forearm and arm. Most of its course is superficial; it generally travels in the subcutaneous fat and other fasciae that lie superficial to the muscles of the upper extremity. Because of this, it is usually visible through the skin.Near the region anterior to the cubital fossa, in the bend of the elbow joint, the basilic vein usually connects with the other large superficial vein of the upper extremity, the cephalic vein, via the median cubital vein. The layout of superficial veins in the forearm is highly variable from person to person, and there are generally a variety of other unnamed superficial veins that the basilic vein communicates with. About halfway up the arm proper (the part between the shoulder and elbow), the basilic vein goes deep, travelling under the muscles. There, around the lower border of the teres major muscle, the anterior and posterior circumflex humeral veins feed into it, just before it joins the brachial veins to form the axillary vein. brachial veins are venae comitantes of the brachial artery in the arm proper. Because they are deep to muscle, they are considered deep veins. Their course is that of the brachial artery (in reverse): they begin where radial veins and ulnar veins join (corresponding to the bifurcation of the brachial artery). They end at the inferior border of the teres major muscle. At this point, the brachial veins join the basilic vein to form the axillary vein.
The brachial veins also have small tributaries that drain the muscles of the upper arm, such as biceps brachii muscle and triceps brachii muscle.
DRAINAGE OF THE HEAD

FETAL HEART foramen ovale (or ostium secundum of Born) allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus (which allows blood that still escapes to the right ventricle to bypass the pulmonary circulation). Another similar adaptation in the fetus is the ductus venosus. In most individuals, the foramen ovale (pronounced /fɒˈreɪmən oʊˈvɑːli/) closes at birth. It later forms the fossa ovalis.

ductus arteriosus (DA), also called the ductus Botalli, is a shunt connecting the pulmonary artery to the aortic arch. It allows most of the blood from the right ventricle to bypass the fetus' fluid-filled lungs, protecting the lungs from being overworked and allowing the left ventricle to strengthen. There are two other fetal shunts, the ductus venosus and the foramen ovale.