Anatomy And Physiology For Health And Social Care.
P2 – Outline The Structure Of The Main Tissues Of The Body
Tissues
A tissue is a large collection of cells that carry out a specific function together. Organisms are made up of groups of different tissues. There are four main types of tissues, these are: Epithelial tissue, Muscle tissue, Connective tissue and Nervous tissue. These four tissue types each have their own specific function vital the human body. Because of this, each type of tissue contain cells with specific organelles appropriate to the tissues function.
Simple Compound Epithelia
The main function of the compound epithelia is to protect deeper structures and multiple layers of cells which obstruct the passage of materials.
The tongue and oesophagus are lined by stratified epithelia consisting of layers of squamous, cuboidal or columnar cells which eventually become flattened by pressure from below as they reach the surface.
The skin has an outer layer of Epithelium which is similar in structure to the stratified epithelium but with extra layer of flattened dead cells on the outside. This is known as Epidermis.
Epithelial Tissues.
Epithelia are the linings of internal and external surfaces in the human body. This includes ducts (tubes or channels) carrying secretions from glands. They may be composed of several layers of cells, called compound epithelia, or just a single layer known as simple epithelia.
The lowest/bottom layer of cells is attached to a basement membrane for connection and support. Secreted by part of the basement membrane are the epithelial cells.
There are nerve supplies to the epithelia but they are supplied by oxygen and nutrients from deeper tissues by diffusion.
Squamous Epithelium.
The simple equilibrium also includes squamous, cuboidal and the columnar epithelia. Squamous epithelial cells are very flat, with each nucleus forming a lump in the centre. The cells are very flat and fit...