Exam 2 – Cardio Ch 21

Question 1

What can happen to muscle blood flow during exercise?

Answer 1

Can increase 20 fold during exercise

Question 2

What makes up a large portion of body mass? What does this have a great effect on?

Answer 2

Muscle

Cardiac output

Question 3

What is the resting blood flow?

Answer 3

to 4 ml/min/100 gm muscle

Question 4

What can happen to the resting blood flow during exercise?

Answer 4

It can increase 15-25X

Question 5

What happens to capillary density during exercise?

Answer 5

It increases markedly

Question 6

When does most blood flow occur during exercise?

Answer 6

Between contractions

Question 7

Look at the changes in capillary density during exercise

Answer 7

Look at the changes in capillary density during exercise

Question 8

Look at the exercise and muscle blood flow chart

Answer 8

Look at the exercise and muscle blood flow chart

Question 9

What happens to heart rate during exercise?

Answer 9

Increase, up to as much as 180 bpm

Question 10

What happens to stroke volume during exercise?

Answer 10

It slightly increases, then decreases

Question 11

What happens to cardiac output during exercise?

Answer 11

Increases, up to as much as 15 L/min

Question 12

Which increases more during exercise, systolic, mean, or diastolic arterial pressure

Answer 12

They all increase, but systolic increases the most.

Mean is second and then diastolic, which barely increases

Question 13

What happens to total peripheral resistance during exercise?

Answer 13

Decreases

Question 14

What happens to oxygen consumption during exercise?

Answer 14

Increases

Question 15

What happens to arteriovenous oxygen difference during exercise?

Answer 15

It increases

Question 16

What happens to blood flow to the heart during exercise?

Answer 16

Increases

Question 17

What happens to blood flow to the brain during exercise?

Answer 17

Stays the same

Question 18

What happens to blood flow to the active skeletal muscle during exercise?

Answer 18

Increases

Question 19

What happens to blood flow to the inactive skeletal muscle during exercise?

Answer 19

Decreases

Question 20

What happens to blood flow to the skin during exercise?

Answer 20

Goes down when you start to exercise, but will go back up once you get hot and it dilates

Question 21

What happens to blood flow to the kidney, liver, gastrointestinal tract, etc during exercise?

Answer 21

Decreases

Question 22

What does decreased oxygen during exercise affect?

Answer 22

Vascular smooth muscle directly, which causes vasodilation

Question 23

What are examples of vasodilators?

Answer 23

K+
Adenosine
Osmolality
Endothelium derived relaxing factor (nitric oxide)

Question 24

What happens during nervous regulation?

Answer 24

Sympathetic release of norepinephrine locally (mainly α)

Adrenals release epinephrine (β and α) and norepinephrine (α and a little β)

Question 25

Look at sympathetic regulation of the circulation

Answer 25

Look at sympathetic regulation of the circulation

Question 26

How much does mean arterial pressure increase during exercise?

Answer 26

20-80 mmHg

Question 27

What does increased blood pressure cause in muscle?

Answer 27

Increased flow

Question 28

What will mean arterial pressure do to blood vessels?

Answer 28

Stretch them causing vasodilation

Question 29

What are the hemodynamic and humoral changes in exercise?

Answer 29

``` Mass sympathetic discharge Decrease parasympathetic impulses HR increases Mean arterial pressure increases Heart strength increased Local vasodilation Global venoconstriction (net effect is increased venous return) Venous return and cardiac output increased ```

Question 30

What does exercise do to circulation?

Answer 30

Redistributes to essential vs non-essential depending on what your body is doing

Question 31

What is the rate of coronary flow?

Answer 31

225 ml/min

Question 32

What vessels are involved in coronary flow?

Answer 32

``` Epicardial Subendocardial (large plexus, least amount of pressure) ```

Question 33

What percentage of the blood comes back through the coronary sinus to the right atrium?

Answer 33

90-95%

Question 34

Look at epicardial and subendocardial vasculature

Answer 34

Look at epicardial and subendocardial vasculature

Question 35

Where are thebesian veins located?

Answer 35

Internally

Question 36

Where do thebesian veins go?

Answer 36

Into the heart

Question 37

How much blood goes through the thebesian veins?

Answer 37

10% or less

Question 38

Look at changes in coronary flow during the cardiac cycle

Answer 38

Look at changes in coronary flow during the cardiac cycle

Question 39

What are the controllers of coronary flow?

Answer 39

Myocardial O2 consumption (pump work) Adenosine – related to decrease O2 Nervous stimuli Others (K+, CO2, Kinins, Prostaglandins, Nitric oxide)

Question 40

Where do nervous stimuli mostly go to?

Answer 40

Sympathetic

Question 41

Where are the nervous stimuli?

Answer 41

Mainly affects epicardial flow (α) Little effect of parasympathetics β sympathetic subendocardial flow

Question 42

What is energy supply for the heart?

Answer 42

``` Fat metabolism (70% fatty acids) Glycolysis (anaerobic) ```

Question 43

How does venous drainage from the heart occur?

Answer 43

Coronary sinus Anterior cardiac veins to right atrium Thebesian veins

Question 44

How does the coronary sinus flow?

Answer 44

Into the right atrium from the left ventricle

Question 45

Where is tissue mass the biggest? Why?

Answer 45

Around the left ventricle | Because of the amount of blood flow

Question 46

What happens as total peripheral resistance increases?

Answer 46

Venous return and cardiac output falls

Question 47

What happens as total peripheral resistance increases and less blood goes to the tissues?

Answer 47

More blood goes to reservoirs and venous return stays the same, which causes higher aortic pressure. Then, there is feedback to decrease sympathetic tone and increase parasympathetic. The slower heart rate and lower force of contraction causes cardiac output to fall

Question 48

What happens as total peripheral resistance decreases?

Answer 48

Venous return and cardiac output increases

Question 49

What happens as total peripheral resistance decreases and more blood goes to tissues?

Answer 49

Causes lower aortic pressure, which leads to less blood staying in the reservoirs and increased venous return because of feedback to increase sympathetic tone and decreases parasympathetic. This leads to higher venous return and higher heart rate and force of contractions, which increases cardiac output