Venule: Difference between revisions

Revision as of 19:59, 8 February 2025

Venule

A venule is a small blood vessel in the microcirculation that allows blood to return from the capillaries to the larger veins. Venules are an essential component of the circulatory system, playing a critical role in the return of deoxygenated blood to the heart.

Structure

Venules are formed when capillaries come together. They are typically 7 to 50 micrometers in diameter. The walls of venules are composed of three layers: the inner endothelium, a middle layer of smooth muscle, and an outer layer of connective tissue. The structure of venules is similar to that of veins, but they are smaller and have thinner walls.

Function

Venules serve as conduits for blood returning to the heart. They collect blood from the capillary beds and transport it to the veins. Venules also play a role in the immune system, as they are sites where white blood cells can exit the bloodstream to reach tissues.

Clinical significance

Venules can be involved in various medical conditions. For example, inflammation can cause venules to become more permeable, leading to edema. In some diseases, such as vasculitis, venules can become inflamed and damaged.

Related pages

References

Guyton, Arthur C.; Hall, John E. (2006). Textbook of Medical Physiology. Elsevier Saunders. ISBN 978-0-7216-0240-0.
"Venule." Encyclopædia Britannica. Encyclopædia Britannica Online.

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-'''Venule'''
+== Venule ==
-A '''venule''' is a very small [[blood vessel]] in the [[microcirculation]] that allows [[blood]] to return from the [[capillary]] beds to the larger [[blood vessels]] called [[vein]]s. Venules range from 7 to 50μm in diameter. Veins contain approximately 70% of total blood volume, 25% of which is contained in the venules.
+[[File:Capillaries.jpg|thumb|right|Diagram showing venules and capillaries]]
-==Structure==
+A '''venule''' is a small blood vessel in the [[microcirculation]] that allows blood to return from the [[capillaries]] to the larger [[veins]]. Venules are an essential component of the [[circulatory system]], playing a critical role in the return of deoxygenated blood to the heart.
-Venules are the smallest branches of the [[venous system]]. They receive blood from the [[capillaries]] and deliver it to the larger blood vessels, the [[vein]]s. The primary function of the venules, similar to the veins, is to return blood to the heart.
+== Structure ==
+Venules are formed when capillaries come together. They are typically 7 to 50 micrometers in diameter. The walls of venules are composed of three layers: the inner [[endothelium]], a middle layer of [[smooth muscle]], and an outer layer of connective tissue. The structure of venules is similar to that of veins, but they are smaller and have thinner walls.
-==Function==
+== Function ==
+Venules serve as conduits for blood returning to the heart. They collect blood from the capillary beds and transport it to the veins. Venules also play a role in the [[immune system]], as they are sites where [[white blood cells]] can exit the bloodstream to reach tissues.
-Venules are responsible for draining oxygen-depleted blood from the capillary beds and returning it to the larger veins, which will eventually return the blood to the heart. They also play a key role in the immune system: the walls of the venules are specialized to allow [[white blood cells]] (leukocytes) to pass through them, in a process known as [[leukocyte extravasation]].
+== Clinical significance ==
+Venules can be involved in various medical conditions. For example, inflammation can cause venules to become more permeable, leading to [[edema]]. In some diseases, such as [[vasculitis]], venules can become inflamed and damaged.
-==Clinical significance==
+== Related pages ==
+* [[Vein]]
-Inflammation of the venules, a condition known as [[venulitis]], can be caused by several conditions including [[autoimmune disorders]], [[infections]], and [[allergies]]. It can result in redness, swelling, and pain in the affected area.
-==See also==
 * [[Capillary]]
-* [[Vein]]
+* [[Artery]]
-* [[Blood vessel]]
 * [[Microcirculation]]
-==References==
+== References ==
+* Guyton, Arthur C.; Hall, John E. (2006). ''Textbook of Medical Physiology''. Elsevier Saunders. ISBN 978-0-7216-0240-0.
+* "Venule." Encyclopædia Britannica. Encyclopædia Britannica Online.
-<references />
+{{Circulatory system}}
-[[Category:Blood vessels]]
 [[Category:Cardiovascular system]]
-[[Category:Anatomy]]
-{{stub}}