Sinusoids
Sinusoids are small blood vessels found in the liver, bone marrow, spleen, and lymph nodes. They are a type of capillary similar to venules, but have a larger diameter and are more permeable, allowing larger molecules and even cells to pass through. Sinusoids are lined with endothelial cells, which have gaps between them, and are surrounded by pericytes.
Structure[edit | edit source]
Sinusoids are unique in structure compared to other blood vessels. They are larger in diameter and have a discontinuous endothelium, meaning there are gaps between the endothelial cells. These gaps, or fenestrations, allow for the exchange of larger molecules and even cells between the blood and the surrounding tissue. The endothelial cells are also unique in that they lack a basement membrane, a thin layer of extracellular matrix that underlies the endothelium in most other blood vessels.
The walls of sinusoids are supported by pericytes, a type of cell that wraps around the endothelial cells. Pericytes are involved in many functions, including regulation of blood flow, immune response, and tissue repair.
Function[edit | edit source]
The primary function of sinusoids is to facilitate the exchange of materials between the blood and the surrounding tissue. This is particularly important in the liver, where sinusoids allow for the exchange of nutrients, waste products, and metabolites between the blood and the liver cells.
In the bone marrow, sinusoids allow for the migration of mature blood cells from the marrow into the bloodstream. In the spleen, they facilitate the removal of old and damaged red blood cells from the circulation.
Clinical significance[edit | edit source]
Due to their unique structure and function, sinusoids are involved in several diseases. In liver disease, such as cirrhosis, the sinusoids can become damaged, leading to impaired liver function. In certain types of cancer, tumor cells can invade the sinusoids, facilitating their spread to other parts of the body.
See also[edit | edit source]
References[edit | edit source]
| Sinusoids Resources | |
|---|---|
|
 |
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
|
WikiMD's Wellness Encyclopedia |
| Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD
