A vessel (for the word origin see under container ; synonym Latin -anatomical vas , in clinical use combinations with angio- from ancient Greek αγγεῖον , "vessel") is a tubular line section for the body fluids blood and lymph in humans and animals. The inner diameter of the vessels is also called the caliber . A distinction is made according to the type of liquid transported:
- Blood vessels ( arteries , veins , capillaries )
- Lymph vessels ( lymph capillaries, collectors, lymph collecting trunks )
Regardless of the type of liquid being transported, the wall structure of larger vessels shows a typical three-layer structure :
Capillaries have only one intima with a basement membrane .
In the case of smaller blood vessels, the supply of the vessel walls takes place via the liquid in the lumen through diffusion ; larger vessels have their own small supply vessels ( vasa vasorum ) , which are located in the adventitia of the vessel to be supplied. The pretension of the vascular wall is controlled by vegetative, predominantly sympathetic nerve fibers .
The inflammation of a blood vessel is called vasculitis ( arteritis in arteries, phlebitis in veins) and can lead to the destruction of the vessel wall (vascular necrosis ) and spread to the surrounding area.