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 Fenestrated capillaries  

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Author16 Posts

Fenestration and frustration!

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Liver is the only organ with fenesterated capillary endothelium which facilitates enhanced exchange of material.




whats the diff between sinusoids and fenestration?
HY mentions that liver has sinusoids, while glomeruli contain fenestrated cap with diaphragms and endocrine organs ( say pancreas in this case) fenestrated cap without diaphragm. could someone explain this to me.


BTW liver is the right answer


medocuk wrote:
Liver is the only organ with fenesterated capillary endothelium which facilitates enhanced exchange of material.

This is not correct, numerous other organs contain fenestrated capillaries and the main function is to support substantial fluid transport. To name a few, intestinal villi, choroid plexus, ciliary processes of the eye...

Sinusoids is a closed circulation within an organ, disorganized in shape. in essense its a "bloody mess", a classic example is the splenic sinusoids.

Edited by Jackofknives on Sep 30, 2007 - 2:10 AM


Thanks JOK. Sorry about the misinformation.




i dont know,according to kaplan q bank, only liver sinusoids have fenestrated endothelium. but anyway, may be they are wrong.




"Fenestration and frustration!" lol!grin

Anyway, it's B.


AntiD - not sure why Kaplan says that. JOK is right - liver, endocrine and glomeruli all have fenestrated endothelium.nod


Just to add...fenestrated capillaries are found manily in kidney. smiling face


ans is b as liver has fenestrated epithelium


my answered is pancrease
Capillaries come in 3 types:

Continuous - Continuous capillaries have a sealed endothelium and only allow small molecules, like water and ions to diffuse. Continuous capillaries have tight junctions and can be further divided into two subtypes:
Those with numerous transport vesicles that are primarily found in skeletal muscles, lungs, gonads, and skin.
Those with few vesicles that are primarily found in the central nervous system. These capillaries are a constituent of the blood-brain-barrier.
Fenestrated - Fenestrated capillaries (derived from "fenestra," the Latin word for "window") have pores in the endothelial cells (60-80 nm in diameter) that are spanned by a diaphragm of radially oriented fibrils and allow small molecules [2][3] and limited amounts of protein to diffuse. In the renal glomerulus there are larger fenestrae which have no diaphragms (although there are pedicels (podocyte foot processes) that have slit pores with an analogous function to the diaphragm of the capillaries). Both types of fenestrated blood vessels have continuous basal lamina and are primarily located in the endocrine glands, intestines, pancreas, and glomeruli of kidney.
Sinusoidal - Sinusoidal or discontinuous capillaries are special fenestrated capillaries that have larger openings (30-40 ?m in diameter) in the endothelium to allow red and white blood cells (7.5?m - 25?m diameter) and various serum proteins to pass, a process that is aided by a discontinuous basal lamina. These capillaries lack pinocytotic vesicles and gaps may be present in cell junctions permitting leakage between endothelial cells. Sinusoid blood vessels are primarily located in the liver, spleen, bone marrow, lymph nodes, and adrenal gland.

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