Vasa vasorum

Vasa vasorum

Micrograph showing cystic medial degeneration. The tunica adventitia (yellow at bottom of image) with vaso vasorum is also seen. Movat's stain.
Details
Identifiers
Latin Vasa vasorum
Code TH H3.09.02.0.06001
TA A12.0.00.028
FMA 77433

Anatomical terminology

The vasa vasorum (Latin, "the vessels of the vessels") is a network of small blood vessels that supply the walls of large blood vessels, such as elastic arteries (aorta) and large veins (vena cava).

Structure

Studies conducted with 3-dimensional microcomputed tomography (3D Micro-CT) on porcine and human arteries from different vascular beds have shown that there are three different types of vasa vasorum:

Depending on the type of vasa vasorum, it penetrates the vessel wall starting at the intimal layer (vasa vasorum interna) or the adventitial layer (vasa vasorum externa). Due to higher radial and circumferential pressures within the vessel wall layers closer to the main lumen of the artery, vasa vasorum externa cannot perfuse these regions of the vessel wall (occlusive pressure).

The structure of the vasa vasorum varies with the size, function and location of the vessels. Cells need to be within a few cell-widths of a capillary to stay alive. In the largest vessels, the vasa vasorum penetrates the outer (tunica adventitia) layer and middle (tunica media) layer almost to the inner (tunica intima) layer. In smaller vessels it penetrates only the outer layer. In the smallest vessels, the vessels' own circulation nourishes the walls directly and they have no vasa vasorum at all.

Vasa vasorum are more frequent in veins than arteries.[2] Some authorities hypothesize that the vasa vasorum would be more abundant in large veins, as partial oxygen pressure and osmotic pressure is lower in veins. This would lead to more vasa vasorum needed to supply the vessels sufficiently. The converse argument is that generally artery walls are thicker and more muscular than veins as the blood passing through is of a higher pressure. This means that it would take longer for any oxygen to diffuse through to the cells in the tunica adventitia and the tunica media, causing them to need a more extensive vasa vasorum.

Function

The vasa vasorum are found in large vein and arteries such as the aorta and its branches. These small vessels serve to provide blood supply and nourishment for tunica adventitia and outer parts of tunica media of large vessels.[3]

Clinical significance

References

  1. Gössl, M; Rosol, M; Malyar, NM; Fitzpatrick, LA; Beighley, PE; Zamir, M; Ritman, EL (Jun 2003). "Functional anatomy and hemodynamic characteristics of vasa vasorum in the walls of porcine coronary arteries.". The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology 272 (2): 526–37. doi:10.1002/ar.a.10060. PMID 12740947.
  2. Carneiro, Luiz Carlos Junqueira, José (2005). Basic histology text & atlas (11th ed.). New York, N.Y., [etc.]: McGraw-Hill. ISBN 978-0-07-144091-2.
  3. 1 2 Loscalzo, editor, Joseph (2010). Harrison's cardiovascular medicine. New York: McGraw-Hill Medical. pp. 2, 33. ISBN 978-0-07-170291-1.
  4. Wolinsky, H; Glagov, S (1969). "Comparison of abdominal and thoracic aortic medial structure in mammals". Circ Res 25: 677–686. doi:10.1161/01.res.25.6.677.
  5. Zervas, NT; Liszczak, TM; Mayberg, MR; Black, PM (Apr 1982). "Cerebrospinal fluid may nourish cerebral vessels through pathways in the adventitia that may be analogous to systemic vasa vasorum.". Journal of Neurosurgery 56 (4): 475–81. doi:10.3171/jns.1982.56.4.0475. PMID 7062119.
  6. Ritman, E; Lerman, A (2007). "The dynamic vasa vasorum". Cardiovascular Research 75 (4): 649–658. doi:10.1016/j.cardiores.2007.06.020. ISSN 0008-6363.
  7. Moore, Keith L.; Dalley, Arthur F.; Agur, Anne M.R. (2010). Clinically oriented anatomy (6th ed., [International ed.]. ed.). Philadelphia [etc.]: Lippincott Williams & Wilkins, Wolters Kluwer. p. 50. ISBN 978-1-60547-652-0.
  8. Isenberg, David A.; Renton, Peter, eds. (2003). Imaging in rheumatology (1st publ. ed.). Oxford [u.a.]: Oxford University Press. p. 304. ISBN 978-0-19-263263-0.
  9. Weyand, CM; Goronzy, JJ (Aug 31, 2000). "Pathogenic principles in giant cell arteritis.". International journal of cardiology. 75 Suppl 1: S9–S15; discussion S17–9. doi:10.1016/s0167-5273(00)00198-4. PMID 10980331.

External links

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