Kapillærvæg

Kapillærvæg refers to the wall of a capillary, which is the smallest type of blood vessel in the circulatory system. These walls are extremely thin, typically only one cell thick. This single layer of cells is known as the endothelium.

The thinness of the kapillærvæg is crucial for its function. It allows for efficient exchange of substances between the blood and the surrounding tissues. Oxygen, nutrients, and hormones can easily diffuse out of the capillaries into the body's cells, while waste products like carbon dioxide and metabolic byproducts can diffuse from the cells into the blood to be transported away.

The endothelial cells that make up the kapillærvæg are specialized for this transport function. They are supported by a basement membrane, a thin layer of extracellular matrix. In some capillaries, there are also pericytes, cells that wrap around the capillary and contribute to its structure and regulation.

The structure of the kapillærvæg can vary slightly depending on the location in the body and the specific needs of the tissue. For example, in organs like the kidneys and liver, where filtration and absorption are key functions, capillaries may have pores or fenestrations in their walls to facilitate faster transport. However, the fundamental characteristic of being a single layer of endothelial cells remains consistent, highlighting the importance of this structure for the vital process of material exchange throughout the body.