Define capillaries and write functions of capillaries.
1 Answer
The capillaries are microscopic, extremely narrow and thin walled blood vessels which connect arterioles to venules. Capillaries help in exchange of various materials like oxygen, food, carbondioxide, between the blood and body cells.
Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins). The primary function of capillaries is the exchange of materials between the blood and tissue cells.There are three types of capillary:
- continuous.
- fenestrated.
- discontinuous.
The exchange of oxygen, nutrients, and waste between your blood and tissues also happens in your capillaries. This happens through two processes:
- Passive diffusion. This is the movement of a substance from an area of higher concentration to an area of lower concentration.
- Pinocytosis. This refers to the process through which your body’s cells actively take in small molecules, such as fats and proteins.