Blood vessel

As a blood vessel (Latin anatomically sanguineum the vas ) or a vein is called in the human or animal body, a tubular structure, a vessel in which the blood is transported. All blood vessels taken together with the heart as a pump organ form the bloodstream.

Intact blood vessels are a condition for the transport of blood to the periphery of the body and the undisturbed flow of blood back to the heart.

Classification

Blood vessels are divided into:

Functionally vasa publica and privata Vasa be distinguished.

Anatomical structure

The wall of a larger blood vessel basically consists of three different layers:

Capillaries consist only of endothelium, are turned on in the pericytes.

Intima

The intima is the innermost layer of the vessel wall of the arteries, veins and lymphatics. It consists of a single layer of aligned along the longitudinal axis of the vessel endothelial cells, which are the gas, liquid and material exchange between the blood and surrounding tissue. It consists of a basement membrane, a layer of the subendothelial connective tissue, and often an internal elastic membrane, which separates the intima from the media.

Media

Media is, depending on the vessel type, in a more or less pronounced muscle layer, which is bounded on both sides of a fiber plate of elastic connective tissue. We distinguish the arteries near the heart of the elastic type (see Windkessel function) and the more distal arteries of the muscular type. Above her is the membrana elastica externa, which separates it from the adventitia.

Adventitia

The adventitia is the surrounding loose connective tissue for anchoring and embedding of the blood vessel in his environment. For larger vessels, it contains vasa vasorum, that fine blood vessels supplying the vascular wall. For smaller blood vessels that supply from the lumen of the vessel is itself