BSI 2 Lecture 18: Microcirculation

Question 1

What is the normal cardiac output at rest?

Answer 1

5 L/min

Question 2

Where does most of the cardiac output go in the body, at rest?

Answer 2

The splanchnic region (organs)

Question 3

Where does the least amount of cardiac output go during rest?

Answer 3

Coronary

Question 4

What is the normal cardiac output while exercising?

Answer 4

25 L/min

Question 5

Where does most of the cardiac output go, during exercise?

Answer 5

Skeletal muscle

Question 6

Why are changes in microcirculation needed?

Answer 6

Because active tissue can require up to a 20 times increase in blood flow, but cardiac output only increases about 6 times

Question 7

What is the difference between smooth muscle contraction and skeletal muscle contraction?

Answer 7

Smooth muscle contraction doesn’t require an action potential

Question 8

What plays the biggest role in local blood flow?

Answer 8

local chemical factors

Question 9

What factors are released from metabolically active tissues?

Answer 9

Carbon dioxide, hydrogen ions, potassium, and others

Question 10

When and what releases nitric oxide?

Answer 10

During high levels of stress from blood flow, endothelium will release nitric oxide to cause vasodilation

Question 11

What does endothelin cause?

Answer 11

vasoconstriction

Question 12

What do bradykinin, prostaglandins, and histamine cause?

Answer 12

arteriole dilation and capillary permeability

Question 13

How does the body respond to ischemia?

Answer 13

Angiogenesis: the increase or decrease in the number of blood vessels