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 cardio 3  



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Author8 Posts
  #1

In which type of blood vessel is the mean linear velocity of a red blood cell the lowest?
A. Aorta and large arteries
B. Arterioles
C. Capillaries
D. Small arteries
E. Vena cavae and large veins
F. Venules and small veins




  #2

E- VENA CAVA AND LARGE VEINS.IT IS LAMINAR/TURBULENT FOLW PHENOMENON. PLEASE CORRECT ME IF I AM WRONG


  #3

"AORTA & LARGE ARTERIES


  #4

i think its capillaries


  #5

i agree w/capillaries also


  #6

yeah capillaries because velocity is inversely proportionate to cross sectional area and capillaries have the largest total cross sectional area.


  #7

The correct answer is C.

The same volume of blood flows through each of the different types of blood vessels each minute.

Because the capillaries have the largest cross-sectional area CSA (averaging 2500-5000 cm2), and because the VELOCITY of blood flow is inversely related to cross-sectional area, it is clear that the mean linear velocity of a red blood cell is lowest in the capillaries.

Under resting conditions, the mean linear velocity of a red blood cell in the capillaries is 0.3-0.6 mm/sec, whereas, the velocity in the aorta (choice A) is about 200 mm/sec. This low velocity of red blood cells in the capillary network allows plenty of time for oxygen to diffuse to the tissues.

The velocity of blood flow is ranked from highest to lowest as follows:

Aorta (choice A) >
Vena Cavae (choice E) >
large veins (choice E) >
small arteries (choice D) >
arterioles (choice B) >
small veins (choice F) >
venules (choice F) >
capillaries.

This ranking assumes the vena cavae have a larger cross-sectional area than the aorta; however, when the vena cavae are partially collapsed (which occurs often) they have a lower cross-sectional area and a higher velocity of blood flow compared to the aorta.


  #8

and If I tell you between the Venae cavae and the the first segment of arterioles, who has the greatest velocity???
By the way arteries have more velocity than Venae Cavae (I Know you wrote small arteries)





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