Veins and Arteries Vs. Capillaries

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Edher
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Veins and Arteries Vs. Capillaries

Post by Edher » Sun Nov 13, 2005 10:59 pm

Saludos,

I have a small curious doubt. How porous are veins and arteries?

In other words, do veins and arteries exchange a lot of chemicals before their arrival to capillary beds, or does the exchange all take place in the capillaries?

Thank You,
Edher

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MrMistery
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Post by MrMistery » Mon Nov 14, 2005 7:28 pm

the wall of capillaries is unistratified, so the vast majority of exchanges take place here.
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Post by Leesa » Tue Nov 15, 2005 8:20 am

Capillaries are semipermeable which means things pass through them, therefore all nutrients and gas exchange takes place in the capillaries, before transfering it to the cells.

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Post by sdekivit » Tue Nov 15, 2005 9:46 am

MrMistery wrote:the wall of capillaries is unistratified, so the vast majority of exchanges take place here.


and there are also cappilairies that are fenestrated --> increased permeability for example in the kidneys.

SciNtist

Veins vs. Arteries

Post by SciNtist » Wed Nov 23, 2005 4:59 pm

Are vein walls more muscular than arteries'?

Jerry

Post by Jerry » Wed Nov 23, 2005 5:04 pm

Do veins have valves on the inside to prevent backflow?

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MrMistery
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Post by MrMistery » Wed Nov 23, 2005 6:20 pm

@jerry
Yes
@SciNtist
Arteries have more muscle fibres than veins...
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Dr.Stein
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Post by Dr.Stein » Fri Nov 25, 2005 7:26 am

Then my question: why arteries are muscular whereas veins are not so? ;)
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Poison
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Post by Poison » Fri Nov 25, 2005 4:57 pm

blood comes to arteries with high pressure, so they are muscular to avoid the pressure affect negatively.
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Post by MrMistery » Fri Nov 25, 2005 9:30 pm

Ozge is right. Arteries are accumulators of pressure, so they need muscle fibers. Veins are accumulators of volume so they need to be able to expand.

By the way, Dr.Stein, was this a test or sth like that? :)
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Dr.Stein
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Post by Dr.Stein » Sat Nov 26, 2005 7:58 am

This was a little quiz like the one that I regularly give to my students in the end of my class or before my next class to provide their comprehension of things they already got from my previous lecture ;)
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Post by Bio-Hazard » Tue Dec 06, 2005 7:25 pm

What causes veins to form into strong arteries when used for a tripple bypass?

Also, when training the cardiovascular system, would the veins become more muscular over time?

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