kapillaarvõrgus

Kapillaarvõrgus refers to the network of capillaries, the smallest blood vessels in the circulatory system. These vessels form a dense network throughout the body's tissues, connecting arterioles and venules. The primary function of the capillary network is to facilitate the exchange of vital substances between the blood and the surrounding cells. This exchange includes oxygen, nutrients, hormones, and waste products such as carbon dioxide.

The structure of capillaries is ideally suited for this exchange. Their walls are extremely thin, typically consisting of a single layer of endothelial cells, and they have a very small diameter, often just wide enough for red blood cells to pass through in single file. This thinness and narrowness minimize the diffusion distance for substances, allowing for efficient transfer.

The capillary network is extensive, ensuring that virtually every cell in the body is in close proximity to a capillary. This ubiquitous presence is crucial for maintaining cellular function and overall tissue health. Blood flow through the capillary network is regulated by precapillary sphincters, which can constrict or relax to control the amount of blood entering specific capillary beds. This regulation allows the body to direct blood flow to areas where it is most needed, such as during exercise or in response to injury. The continuous process of exchange within the kapillaarvõrgus is fundamental to life.