Epithelial Tissue
3 types of epithelial cells are: 1. Squamous 2. Ciliated 3. Goblet cells
Squamous Epithelial Cells
Squamous epithelial cells are generally round and flat with a small, centrally located nucleus. These cells line any surface that come in contact with the external environment and function as mediators of filtration and diffusion.
Ciliated Epithelial Cells
Ciliated epithelial cells have 200-300 small, hair like protrusions known as ‘cilia’ that can do one of two things at a time; they can help cells move along the tissue, or can help debris and waste to move along the surface of cells. Ciliated cells are most often found in the body’s air passages, this includes the lungs, trachea and nose.
Goblet Cells
Goblet cells are column shaped cells that are found mostly in the respiratory and intestinal tracts. Goblet cells secrete the main component of mucus (mucins). Goblet cells are a source of mucus in tears and secrete various types of mucins onto the optical surface, especially in the conjunctiva which is located in the upper eye lid.
On the interior surface of the intestine, goblet cells help to form a thick layer of mucus that protects and lubricates the organ.
Blood
Blood runs through the veins, arteries, and capillaries (known as whole blood – contains all blood cells)
Blood has many different functions, including: * transporting oxygen and nutrients to the lungs and tissues * forming blood clots to prevent excess blood loss * carrying cells and antibodies that fight infection * bringing waste products to the kidneys and liver, which filter and clean the blood * regulating body temperature
There are 3 main components in blood, these are: 1. Red blood cells 2. White blood cells 3. Blood platelets
Red Blood Cells
Red blood cells are shaped like round discs with a small dip in the middle and are known for their bright red colour. Red blood cells are mainly responsible for the transportation of oxygen and are released from bone marrow after 7 days of maturation.
White Blood Cells
White blood cells are round balls that have small points around the surface. White blood cells protect the body from harmful bacteria and pathogens by engulfing and ingesting the foreign substances.
Blood Platelets
Platelets are small, colourless and disk-shaped that helps the blood clotting process (coagulation). They’re found around the site of an injury, sticking to the lining of the injured blood vessel. If a person has a very high number of blood platelets then this would cause unnecessary clotting which can lead to a stroke or heart attack.
Cartilage
Cartilage is a hard, thick connective tissue that is found at the ends of bones, this helps to form joints.
There are 3 different types of cartilage, these are Hyaline, Elastic, and Fibrocartilage. * Hyaline cartilage, also known as articular cartilage, is the most common cartilage throughout the body and if found in joints and on the edge of ribs, it is also responsible for the shape of the nose. It comprises large protein molecules (e.g. collagen) this forms the cartilage’s matrix. This is the prime material within this type of cartilage. * Elastic cartilage has a lot of the same materials as hyaline, however for this cartilage the main component is elastic fibres, this gives it more flexibility. This type of cartilage is what ears are made of and is also found in the epiglottis (the part of the body that prevents food and drink from going through to the lungs. * Fibrocartilage can be found in the knee joint and between the spinal vertebrae. It resists compression, limits relative movement and prevents bone-to-bone contact http://www.todayifoundout.com/index.php/2014/02/ears-nose-continue-grow-age/ Our ears and nose are made completely of cartilage, as a result of this they never stop growing since Cartilage is made up of protein strands called collagen, this forms a tough, mesh-like framework that is filled with substances that hold water as a sponge would. When weight is placed on cartilage the water is squeezed out, and then when weight is taken off the water returns.
Bone
Bone is a thick, hard solid and makes up our bodies. Bones have many functions, these include: * Metabolic functions where the bones help to store substances such as minerals (e.g. calcium) * Mechanical functions where bones join together to form the skeleton that protects our organs, for example the skull protects the brain and ribs protect the heart and lungs. Another mechanical function can be that bones play a part in hearing, the ossicles are 3 small bones in the middle hear that help with hearing sounds.
Bones give our bodies shape, support and protect the most important organ and systems in our bodies. Bones also help to produce both white and red blood cells in bone marrow. Although bones are lightweight, they are still strong and hard, which helps us to be able to move around without getting hurt or end up easily breaking a bone.
When we are born, we have a total of 270 bones in our bodies, but as we grow some of these bones fuse together for extra stability and protection, for example our skulls are, at first, 3 separate bones but they fuse together around the age of 2 to ensure extra protection for our brain. By the time all of our bones have fused together there are a total of 206 bones in our bodies.
Areolar Tissue
Areolar tissue is made up of loose connective tissue that consists of a meshwork of collagen, elastic tissue and reticular fibres. It binds skin to our muscles beneath. Areolar tissue is found in many places of the body, but it is found most specifically in the skin area.
Adipose Tissue
Adipose tissue is found mainly under the skin but also in the layers between the muscles, the intestines and around the heart and more. The fat stored in adipose tissue come from dietary fats or is produced in the body, it also stores energy in the form of fat, although it also cushions and insulates the body. Some animals (mammals) have 2 different types of adipose, white adipose tissue and brown adipose tissue.
Striated Muscle
Striated muscle, also known as the skeletal muscle, is made of dense, fibrous tissues that is attached mainly to the bones and skin. Striated muscle’s primary function is to allow the body to move. It does this through repeated contraction and relaxation. Other than movement, muscle is also responsible for maintaining posture, stabilizing joints and producing body heat through muscle function.
Sensory & Motor Neurones
Sensory and motor neurones look similar to each other, however they have separate functions and are found in different places.
Sensory neurones are found within the nervous system and are responsible for altering external stimuli from the organisms environment into internal electrical impulses to communicate with the brain.
Motor neurons are found in the spinal cord, they synapse with muscle fibres to facilitate muscle contraction and with muscle spindles to adapt proprioceptive sensitivity.