Please explain stratified transitional and simple squamous.
These are types of epithelial tissues which cover body structures and line body cavities. Epithelial tissues are avascular because of their anatomy.
Stratified transitional epithelium consists of many sheets or layers of cells which function as a protective barrier. The tissue is capable of stretching, it is very elastic in nature. The urinary bladder contains these types of tissues hence it can stretch and hold a vast amount of urine.
Simple squamous epithelium unlike stratified is a single layer of cells, this enables the cells to be an excellent way for the body to diffuse gases between structures. These types of tissues are found in the alveoli of the pulmonary membrane where respiratory gases are exchanged between the blood of the venous and arterial systems.
Stratified transitional epithelium has several layers of cells and allows for great flexibility and stretching --as found in the bladder.
Simple squamous epithelium is only a single layer thick and the cells are flattened plates which is smooth and low friction. This tissue allows for easy diffusion of liquids or gases --as in the lungs and bloodvessels.