Vascular Shunt Mechanism

Question 1

What is vascular shunt

Answer 1

Blood is redistributed towards active skeletal muscle during exercise and away from inactive organs. As body heat builds up some blood flow is shifted to the skin to help maintain temperature levels.

Question 2

At rest what % of blood is directed to the organs and muscles ?

Answer 2

80 % - organs
20 % - muscles

Question 3

Vascular Shunt Mechanism -
organs - rest (cm3)- %blood flow - max effort - %blood flow

Answer 3

Muscles - 1000-20-26000-88
Skin - 500-10-750-2.5
Kidney - 1000-20-375-1.25
Brain - 750-15-750-2.5

Question 4

What does the vascular shunt mechanism use ?

Answer 4

Used a network of blood vessels to control where the blood in the body goes

Question 5

What are arterioles ?

Answer 5

Smaller arteries

Question 6

Where does gaseous exchange occur ?

Answer 6

Arterioles (smaller arteries) leads to capillary beds, which is where gaseous exchange occurs

Question 7

Blood flow to the capillary beds is controlled by what ?

Answer 7

Precapillary sphincters

Question 8

What are precapillary sphincters ?

Answer 8

Little muscle rings at the end of arterioles and these either : vasodilate or vasoconstrict

Question 9

What is vasodilation

Answer 9

Widening of the lumen which allows blood flow

Question 10

What is vasoconstriction?

Answer 10

Narrowing of the lumen which prevents / restricts blood flow

Question 11

What blood vessels are primarily responsible for the vascular shunt mechanism

Answer 11

Arterioles