Unit 5 Anatomy and physiology Functions of the component of the human cell.( http://www.slideshare.net/kristenaoconnor/cell-organelles)
Cell membrane: the cell membrane also known as plasma membrane is the biological membrane that separates the interior cell from the outside environment. It provide support and protection for the cell. It serves as the entrance and exit of the cell.
Cytoplasm: cytoplasm is a jelly like material that fill the cell. It contains food and water for the cell. It holds the organelle in place. It is mainly composed of water, salt and proteins.
Nucleus : it contains the majority of genetic materials as DNA molecules along with variety of protein to form chromosomes. which makes humans who and what they are.
Endoplasmic reticulum: the endoplasmic reticulum serves many functions, it folds protein molecules in sacs cisternae, it transports synthesized proteins in the vesicles to the Golgi apparatus.
Golgi apparatus: it is made up of membrane bound sacs .The function of the Golgi apparatus is to process and bundle macromolecules like protein and lipids as they synthesize in the cell. It modifies sorts and package proteins to be secreted.
Mitochondria: it is of the referred to as the powerhouse . It breaks down food and release energy to the cell.
Lysosomes: they organelle that contain the digestive enzymes. It cleans up the cell’s waste product.
Centriole: the main function of the centriole is to help the division in cells. It also helps in the formation of the spindle fibre s that separate the chromosomes during cell division. Chromatin: the main function of the chromatin is to efficiently package DNA into small volume to fit into the nucleus of the cell and protect the DNA structure and sequence. Chromatin also allows for mitosis and meiosis prevent chromosome breakage and control s gene expression and DNA replication.
Ribosome: it can be found floating in the cytoplasm or attached to the endoplasmic reticulum. It repairs damage and direct chemical processes.
Vacuole: it is storage bubbles found in the cell. They are found in both plant and animal cells. It surrounded by a membrane and It holds materials and waste products.

P2 The main tissues of the body
Tissues are a group of similar cells performing a specific functions.(Atkinson 2015) There are basically four types of tissues in the human body namely, Epithelia, connective, muscular and nervous tissues. Each of these tissues has it’s functions.
Epithelia tissue covers the whole body surface and form the lining for the internal cavities. It is made up cells closely parked and arranged in one or more layers. Epithelia tissue can be divided into two groups depending on the number of layers it compose of. The two types epithelia tissues are, simple epithelium and stratified epithelium Simple Epithelia:
Simple epithelia
This has one thick layer and can be divided according to the functions of the cells as follows
Cuboidal epithelium: these are called cuboidal because it has shape of cuboids and are found in glands ducts and kidney tubules lining. They also play roles in the production of egg cells in female ovary and sperm cells in males.
Columnar epithelium: these are shaped like columns and found in one or more layers. They form the lining of the stomach and intestines. Some are also involved with sensory organs such as tongue (taste buds) ears and nose.
Squamous epithelium: these are thin and flat in appearance and are responsible for the lining of mouth cavity, heart, lungs and blood vessels. They also make the outer layer of the skin.
Compound or Stratified Epithelia
These Epithelia are made up of several layers of cells and this is in order to withstand wear and tear of the body lining. Compound Epithelia can be keratinised or non keratinised. found Keratinised Stratified Epithelium: these are dry and contain a high resistant protein called keratin. These are be in mammal skins, hair and nails and it serves as protection to the body.
Non Keratinised Stratified Epithelium: these are wet and does not contain keratin. They can be found in the lining of the mouth cavity, oesophagus and during eyes lubrication.
. Epithelia tissue is the first to differentiate the embryo. It is found in the duct and the glands. Epithelia line between most organs such as the stomach and the intestines, the kidney and pancreas. It also lines the oesophagus. The image below shows the structure of epithelia tissues. The functions of epithelia tissue are as follows.
Protection: epithelia tissue protects the underlining tissues from mechanical injure, harmful injure. It invade bacteria and excessive loss water.
Sensation: sensory stimuli penetrate specialise epithelia tissues containing sensory nerves ending is found in the skin, eyes ,ears, nose and the tongue
Secretion: epithelia in the glands is specialised to secrete specific chemical substances such as the enzymes, hormones and lubrication fluids.
Excretion :epithelia tissue in the kidney excrete waste product from the body and reabsorb needed materials from the from the urine. Sweat is also excreted from the body by epithelia cell in the sweat glands.
Absorption: epithelia cells in the small intestine absorb nutrients from digestion of food.
Diffusion: simple epithelium promotes the diffusion of gases , liquid and nutrients.as they form lining , they are ideal for the diffusion of gases. Example wall, capillaries and the lunge.
Cleaning : ciliated epithelium assist in the removing dust particles and foreign bodies which have entered the air passage.
Connective tissues: they are most widely distributed inbody and lie under the the epethelial tissues. They connec different part of the internal structure. The main functions of the connective tissues are: the cartilage bind and support other tissues in the body. Connective tissues allow the passage for nerves and blood vessels through other tissues. Connective tissues also tansport nutients and metabolic byproducts btween the bloodstream and the othe tissues. Cnnective tissues are made up of proteins like collagen , elastin and intercellular fluids. Connective tissue basdically binds together all types of tissues. IT also reponsible foer secretion of intercellular ground sustances known as the matix. The matix maybe liquid such as blood.
(ttps://www.google.co.uk/search?q=microscopic+images+of+nervous+tissue&es_sm=9)

The nervous tissue:( ttps://www.google.co.uk/search?q=microscopic+images+of+nervous+tissue&es_sm=9) The nervous tissue is responsible for sensing stimuli and transmitting signals to and from different part of the parts of an organism. The basic unit of the nervous system is the neurons. The nervous tissue brings about a response to the stimulus as in the brain, spinal cord and epithelia nerve. The stimuli are integrated to provide co-ordinated response in various organs. The sensory neuron helps nerve impulse from the sense organs to the central nervous system.
The muscular tissue Muscular tissue are divided into three main groups according to their structure. These are smooth muscles, skeletal muscles and cardiac muscles tissues. The functions of the muscular tissues are as follows
The muscular tissue allow movement in the body and it’s parts. The function of the muscular tissue muscular depends on the location of the tissue. muscular tissue stabilizes joints. It adds stability to joints that have poor reinforcement and articulates surface that do not fit well, such as in the shoulder and the knee joints. It also helps to maintain posture and contracts adjustments almost to continuously to the body in stationary position such as sitting or standing. The cardiac tissue tissues enhance the contraction of the atria and the ventricles of the heart . It causes the rhythmical beating of the heart, circulating the and its content throughout the body as a sequence. The smooth muscular tissue controls slow involuntary movements such as the contraction of the muscle tissue in the wall of the stomach and the intestines.