Discuss the structure of the three fundamental types of capi

Discuss the structure of the three fundamental types of capillary endothelium, mention their different functional roles and give an example of where a representative of each may be found.

Solution

Endothelial capllaries main function is to keep blood separate from the rest body tissues, organs and cavities. They found in arteries, veins and lymphatic vessels. Endothelium is single cell thick layer, it is selectively permeable for chemicals and molecules as an when needed. They helps in formation of blood vessels, regulating blood pressure, production of nitric oxide (NO), blood coagulation and cause inflammation when infected. They help in exchange of molecules and water regulation in the body.

There are three types of endothelial capillaries-

1. Continuous: They are present underneath or around the capillaries, pericytes are associated with them. These capilaries are source of fibroblast

2. Fenestrated: These capillaries are for extensive molecular exchange, these are found in small intestine, endocrine glands and kedney.

3. Discontinuous: These are found in liver. They are formed between the endothelial cells of sinusoids and hepatic cells. These produces large clefts between the two layers of cells that allowes protein or even the blood cells to pass through