Venule
| Venule | |
|---|---|
 Types of blood vessels, including a venule, vein, and capillaries | |
| Details | |
| Identifiers | |
| Latin | venula |
| MeSH | D014699 |
| TA98 | A12.0.00.037 |
| TA2 | 3903 |
| TH | H3.09.02.0.03002 |
| FMA | 63130 |
| Anatomical terminology | |
A venule is a very small
venous system via increasingly larger veins. Post-capillary venules are the smallest of the veins with a diameter of between 10 and 30 micrometres (μm). When the post-capillary venules increase in diameter to 50μm they can incorporate smooth muscle and are known as muscular venules.[1] Veins contain approximately 70% of total blood volume, while about 25% is contained in the venules.[2]
Many venules unite to form a vein.
Structure
 | This section needs more primary sources. (April 2018) |  |
Post-capillary venules have a single layer of endothelium surrounded by a
arterioles
. They are porous so that fluid and blood cells can move easily from the bloodstream through their walls.
Short portal venules between the posterior pituitary and the anterior pituitary lobes provide an avenue for rapid hormonal exchange via the blood.[3] Specifically within and between the pituitary lobes is anatomical evidence for confluent interlobe venules providing blood from the anterior to the neural lobe that would facilitate moment-to-moment sharing of information between lobes of the pituitary gland.[3]
In contrast to regular venules,
simple cuboidal cells. Lymphocytes
exit the blood stream and enter the lymph nodes via these specialized venules when an infection is detected. Compared with arterioles, the venules are larger with much weaker muscular coat. They are the smallest united common branch in the human body.
See also
References
- ^ ISBN 9780702052309.)
{{cite book}}: CS1 maint: location missing publisher (link - ISBN 9780781792806.
- ^ S2CID 23657199.
External links
| National | |
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| Other | |
