ANS and Cardiovascular system W3

Question 1

What is cholinergic?

Answer 1

Acetylcholine

Question 2

What is adrenergic?

Answer 2

Norepinephrine

Question 3

What causes the initial increase of heart rate at the onset of exercise?

Answer 3

Initial increase due to parasympathetic withdrawal

Question 4

What causes the later increase of heart rate at the onset of exercise?

Answer 4

Due to SNS outflow

Question 5

What is end-diastolic volume (EDV)?

Answer 5

Volume of blood in the ventricles at the end of diastole (“preload”)

Question 6

What is average aortic blood pressure?

Answer 6

Pressure the heart must pump against to eject blood (“afterload”)
Mean arterial pressure

Question 7

What regulates stroke volume?

Answer 7

End-diastolic volume
Average aortic blood pressure
Strength of the ventricular (contractility)

Question 8

What is the strength of the ventricular (contractility) enhanced by?

Answer 8

Circulating epinephrine and norepinephrine
Direct sympathetic stimulation of heart

Question 9

What is end-diastolic volume dependent on?

Answer 9

Venous return

Question 10

How is venous return increased?

Answer 10

Vasoconstriction
Skeletal muscle pump
Respiratory pump

Question 10

What is frank starling mechanism?

Answer 10

Greater EDV results in a more forceful contraction

(due to stretch of ventricles)

Question 11

How is vasoconstriction increased?

Answer 11

Via SNS

Question 12

How is skeletal muscle pump increased?

Answer 12

Rhythmic skeletal muscle contractions force blood in the extremities toward the heart

One-way valves in veins prevent backflow of blood

Question 13

How is respiratory pump increased?

Answer 13

Changes in thoracic pressure pull blood towards the heart

Question 14

What is cardiac output?

Answer 14

The amount of blood pumped by the heart each minute

Question 15

What is formula for cardiac output?

Answer 15

Q= HR x SV

HR= Cardiac Rate
SV= Stroke Volume

Question 16

What is systolic pressure?

Answer 16

Pressure generated during ventricular contraction

Question 17

What is diastolic pressure?

Answer 17

Pressure in the arteries during cardiac relaxation

Question 18

What is pulse pressure?

Answer 18

Difference between systolic and diastolic

Question 19

What is mean arterial pressure (MAP)?

Answer 19

Average pressure in the arteries

Question 20

What are determinants of Mean Arterial Pressure?

Answer 20

Cardiac Output
Total Vascular resistance

Question 21

What is total vascular resistance?

Answer 21

Sum of resistance to blood flow

Question 22

What is the formula for MAP?

Answer 22

MAP= Cardiac Output x Total Vascular Resistance

Question 23

What is short-term regulation for arterial blood pressure?

Answer 23

Sympathetic nervous system
Baroreceptor in aorta and carotid arteries

Question 24

How does blood pressure influence SNS activity?

Answer 24

Increase in BP= Decreased SNS activity Decrease in BP= Increased SNS activity

Question 25

What is long-term regulation for arterial blood pressure?

Answer 25

Kidneys (via control of blood volume)

Question 26

What mechanisms increase blood flow delivery to exercising skeletal muscle?

Answer 26

Increased cardiac output Redistribution of blood flow from inactive organs to the working skeletal muscle

Question 27

What is cardiac output increase during exercise directly proportional to?

Answer 27

The metabolic rate required to perform the exercise

Question 28

What are circulatory responses to exercise dependent on?

Answer 28

Type, Intensity, Duration of Exercise Environmental Conditions Emotional influence pre-exercise and during submaximal exercise

Question 29

What are the circulatory responses to exercise?

Answer 29

Changes in heart rate Changes in blood pressure

Question 30

What happens at the onset of exercise?

Answer 30

Rapid increase in heart rate, SV, Cardiac output Plateau in submaximal exercise (below lactate threshold)

Question 31

What happens during exercise to recovery stage?

Answer 31

Decrease in HR, SV and Cardiac Output toward resting levels Depends on duration/intensity of exercise and training state of subject

Question 32

What happens to heat rate and cardiac output during incremental exercise?

Answer 32

Increases linearly with increasing work rate Reaches plateau at 100% VO2 max

Question 33

What happens to blood pressure during incremental exercise?

Answer 33

Mean arterial pressure increases linearly - Systolic BP increases - Diastolic BP remains fairly constant

Question 34

What happens to cardiac output during prolonged exercise at a constant work rate?

Answer 34

It is maintained Gradual decrease in stroke volume= due to dehydration and reduced plasma volume

Question 35

What happens to heart rate during prolonged exercise?

Answer 35

Gradual increase in heart rate during prolonged exercise (cardiovascular drift)