capillary vs vein

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airsimon

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Is the slowest place for the movement of blood in the human capillary or in the vein? I answered capillary but on 2nd thought I'm not sure.
 
yea capillaries because of gas and nutrients exchange
 
Is the slowest place for the movement of blood in the human capillary or in the vein? I answered capillary but on 2nd thought I'm not sure.


The slowest place would be at the capillaries because, like the person above me said, it is the site of gas/ nutient exchange. If u want to think in terms of physics this is due to the smaller diameter which leads to more blood that is in contact with the walls (resistance) of the capillaries. This resistance thus slows down the bulk flow of the blood.


Hope this made sense.
 
If I'm not mistaken, capillary should be the fastest, since it is smaller in diameter, blood has more blood pressure in it.

The area of every individual capillary is indeed the smallest of all the blood vessels.

However, there are so many capillaries throughout the body that their total cross sectional area (that is all the cross sectional areas for each capillary added up) is very, very great.

Thus, blood moves slowest in the capillaries.
And this functions well for gas and nutrient exchange across capillary walls.
 
veins have the largest diameter and capillaries the smallest...therefore, capillaries have the slowest rate of blood flow since the diameter is inversely proportional to the resistance. (i.e big diameter=less resistance=more flow, and small diameter=more resistance=less flow)
 
veins have the largest diameter and capillaries the smallest...therefore, capillaries have the slowest rate of blood flow since the diameter is inversely proportional to the resistance. (i.e big diameter=less resistance=more flow, and small diameter=more resistance=less flow)

So blood flow is fastest through veins? I thought it was arteries...
 
airsimon, you are right. in increasing order, it goes: capillaries, veins, arteries. Veins must fight gravity to get back to the heart, (most of them, which is why they have valves, etc) arteries get the large ventricle push as well as taking advantage of gravity (except to the head neck region, etc)
 
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