kapillárakerfið

The kapillárakerfið, or capillary system, refers to the network of tiny blood vessels in the circulatory system. These vessels are the smallest in the body, with diameters typically ranging from 5 to 10 micrometers, just wide enough for red blood cells to pass through in single file. The primary function of the kapillárakerfið is to facilitate the exchange of vital substances between the blood and the body's tissues.

Through the thin walls of the capillaries, oxygen and nutrients are delivered to the cells, while carbon dioxide and metabolic waste products are picked up to be transported away. This crucial process, known as diffusion, is highly efficient due to the large surface area provided by the extensive network of capillaries throughout the body and their extremely thin walls. Capillaries connect arterioles, which carry blood away from the heart, to venules, which carry blood back towards the heart.

The kapillárakerfið plays a critical role in maintaining homeostasis, ensuring that all cells receive what they need to function and that waste is efficiently removed. The regulation of blood flow through the capillaries is precisely controlled by precapillary sphincters, which can constrict or relax to adjust the amount of blood reaching specific tissues based on their metabolic demands. This intricate system is fundamental to the health and survival of all multicellular organisms.