Heart and Stomache Essay

Submitted By africangal22
Words: 1712
Pages: 7

anatomy and physiology
TASK 2:
I will produce a written assignment which shows an understanding of the four main tissue types and the role play also the functioning of the two organs (stomach and heart).
EPITHELIAL TISSUE:
Epithelial tissues are tissues that cover or line the whole body surfaces, they are made up of cells closely packed and organised in one or more layers. Epithelial tissues are focused in the covering or lining of inner and outer body surfaces; despite of the types of epithelial tissues they are generally separated starting at the underlying tissue by a thin sheet of connective tissue.
Epithelial tissues can be separated into two groups depending on the number of layers of which it’s composed, if the epithelial tissue is only one cell thick it is known as simple epithelium, if it is two or more cells thick for instance the skin then it is known as the stratified epithelium.
Simple epithelium tissues can be branched according to the shape and function of its cells for example: * Squamous (pavement) epithelium: have the form of thin, flat plates; the shape of the nucleus typically corresponds to the cell form helping to recognize the type of epithelium. Squamous cells tend to have horizontal flattened, elliptical nuclei for the reason that of the thin flattened form of the cell, forming the lining of cavities for instance the mouth, blood vessels, heart, lungs and making up the outer layers of the skin.

* Simple cuboidal epithelium: they are generally square or cuboidal in shape; each cell has a spherical nucleus in the centre and is found in glands also the lining of kidney tubules additionally in the ducts of the glands. They compose the germinal epithelium which generates the egg cells in the female ovary plus the sperm cells in the male testes.

* Simple Columnar Epithelium: they happen in one or more layers, the cells are stretched out also column-shaped. The nuclei are extended which are generally situated near the base of the cells; simple columnar epithelium forms the lining of the stomach and intestines, some which are focused for sensory response such as in the nose, ears and the taste buds of the tongue. Goblet cells (unicellular glands) are institute between the columnar epithelial cells of the duodenum; they conceal mucus or slime, a lubricating substance which keeps the surface smooth.

* Stratified Epithelium: where body linings have to hold up wear and tear, the epithelia are made up of numerous layers of cells which are known as compound or stratified epithelium. The top cells are flat and crusty and it may or may not be keratinised (contains a tough, resistant protein called keratin). The bodily skin is an example of dry, keratinised, stratified epithelium, lining of the mouth cavity is an example of an unkeratinisied, stratified epithelium.

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Functions of Epithelial Tissue
The functions of epithelial tissues are: 1. Protection of skin also underlying tissue from reflex injury, dangerous chemicals, invading bacteria and from extreme loss of water. 2. Sensation focused on epithelial tissue containing sensory nerve endings found in the skin, eyes, ears, and nose also the tongue. 3. Secretion in glands focused to hide particular chemical substances like enzymes, hormones and glands lubricating fluids. 4. Absorption of the cells lining the small intestine to take in nutrients from the digestion of food. 5. Excretion in the kidney which discharges waste products from the body and re takes essential materials from the urine. Sweat is also discharged from the body by epithelial cells in the sweat glands. 6. Diffusion of simple epithelium promoting the transmission of gases, liquids also nutrients for the reason that they form such a thin lining and are ultimate for the flow of gases (walls of capillaries and lungs). 7. Cleaning of the ciliated epithelium assists in removing dust particles and unfamiliar bodies which have entered…