Vasa vasorum

Vasa vasorum (Latin for "vessels of the vessels") are small blood vessels that supply the walls of large blood vessels, such as elastic arteries (aorta) and large veins (vena cava). They provide nutrients and oxygen to the outer part of the vessel wall, which is too thick to be nourished by diffusion from the blood in the vessel lumen.

Structure

The vasa vasorum are found in the adventitia and outer part of the media of large arteries and veins. They are more prominent in veins than in arteries, as the walls of veins are generally thicker relative to their lumen size. The vasa vasorum can be classified into three types:

• Vasa vasorum interna: These originate from the main vessel lumen and penetrate the vessel wall.
• Vasa vasorum externa: These arise from branches of adjacent arteries and veins and supply the outer layers of the vessel wall.
• Vasa vasorum venosa: These drain the blood from the vessel wall into the main vessel lumen or into adjacent veins.

Function

The primary function of the vasa vasorum is to supply blood to the outer layers of large blood vessels. This is crucial for maintaining the health and function of the vessel wall, as the inner layers receive nutrients directly from the blood flowing through the vessel lumen. The vasa vasorum also play a role in thermoregulation and in the response to injury or inflammation of the vessel wall.

Clinical significance

The vasa vasorum are involved in various pathological conditions. In atherosclerosis, the proliferation of vasa vasorum can contribute to plaque growth and instability. In conditions such as Takayasu's arteritis and Giant cell arteritis, inflammation of the vasa vasorum can lead to vessel wall damage and stenosis.

Related pages

• Atherosclerosis
• Arteritis
• Blood vessel

Gallery

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  Micrograph showing cystic medial degeneration, a condition that can affect the vasa vasorum.

References

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  Cystic medial degeneration - movat - intermediate magnification