kapillárium

Kapillárium is a term used in biology and medicine to refer to the smallest blood vessels in the body. These microscopic vessels form a network that connects arterioles (small arteries) to venules (small veins). The primary function of capillaries is to facilitate the exchange of oxygen, nutrients, and waste products between the blood and the surrounding tissues. Their thin walls, typically composed of a single layer of endothelial cells, allow for efficient diffusion.

The capillary network is extensive, ensuring that every cell in the body is within close proximity to a blood supply. This vast network plays a crucial role in maintaining homeostasis by regulating blood flow and pressure, as well as transporting essential substances necessary for cellular function. The diameter of capillaries is usually just wide enough for red blood cells to pass through in single file, further optimizing the surface area for exchange.

Different types of capillaries exist, including continuous, fenestrated, and sinusoidal, each adapted to the specific needs of the tissues they serve. Continuous capillaries are the most common and are found in muscles, lungs, and the central nervous system. Fenestrated capillaries, with pores in their walls, are characteristic of organs involved in rapid filtration or absorption, such as the kidneys and intestines. Sinusoidal capillaries, with larger gaps between endothelial cells, are found in organs like the liver and spleen, allowing for the passage of larger molecules and even cells. The health and function of the capillary system are vital for overall circulatory health.