Circulation

Question 1

what is the site of variable blood flow resistance ? can the capillaries constrict ?

Answer 1

arterioles

No

Question 2

how is the inner lining of all blood vessels called ? which vessels have smooth muscle, elastic tissue ?

Answer 2

endothelium

muscle : artery, arteriole, veins
elastic : artery, vein

Question 3

explain the “wind boiler” function of the aorta

Answer 3

systole : half of blood goes to the arterioles, other half enlarges the aorta (systolic pressure)

diastole : elastic property of aorta pushes the remaining blood to the arterioles (diastolic pressure)

Question 4

what is pulse pressure ?

Answer 4

systolic pressure - diastolic pressure (= strength of pressure wave)

This can be felt on the artery radialis

Question 5

4 things the mean arterial pressure depends on, endurance athletes ?

Answer 5

1) blood volume

2) cardiac output : heart rate and stroke volume

3) resistance : diamater of arterioles

4) distribution of blood between arteries and veins

athletes : higher blood volume (stroke volume) but lower resting heart beat -> same cardiac output

Question 6

why is the blood velocity in capillaries so low ?

Answer 6

it depends on the total cross-sectional area -> big area = smaller velocity