Regulation of Cardiac Activity and Circulation

Question 1

What happens to the arterial pressure as compliance decreases?

Answer 1

The systolic pressure will increase and the diastolic pressure will decrease.

The pulse pressure will widen as a result.

Question 2

What happens to the arterial pressure as the peripheral resistance increases?

Answer 2

The systolic and diastolic pressure will both increase but the diastolic pressure will increase much more.

Question 3

What happens to the arterial pressure as compliance increases?

Answer 3

The systolic pressure will decrease and the diastolic pressure will increase.

The pulse pressure will narrow as a result.

Question 4

What happens to the arterial pressure as peripheral resistance decreases?

Answer 4

The systolic and diastolic pressure will both decrease, but the diastolic pressure will decrease more.

Question 5

How does an increase in the cardiac output affect the mean arterial pressure?

Answer 5

It will increase it

Question 6

How does an increase in the heart rate affect the mean arterial pressure?

Answer 6

It will increase the cardiac output, which will increase the mean arterial pressure.

Question 7

How does an increase in venous return affect mean arterial pressure?

Answer 7

It will increase the cardiac output and it will increase the mean arterial pressure.

Question 8

How does a decrease in the blood volume affect the mean arterial pressure?

Answer 8

It will lower the venous return and lower the mean arterial pressure.

Question 9

How does anemia affect the mean arterial pressure?

Answer 9

It will lower the hematocrit, which will decrease blood viscosity and it will decrease the resistance which will decrease the mean arterial pressure.

Question 10

How does increased metabolic activity affect the mean arterial pressure?

Answer 10

Metabolites will cause dilation of the vessels and the resistance will decrease as a result, and the mean arterial pressure will be decreased.

Question 11

How will angiotensin affect the mean arterial pressure?

Answer 11

It will cause vasoconstriction, which will increase the resistance and increase the pressure.

Question 12

What is the mean right atrial pressure?

Answer 12

2 mmHg

Question 13

What is the right ventricular systolic pressure?

Answer 13

25 mmHg

Question 14

What is the right ventricular diastolic pressure?

Answer 14

2 mmHg

Question 15

What is the mean left atrial pressure?

Answer 15

6 mmHg

Question 16

What is the left ventricular systolic pressure?

Answer 16

120 mmHg

Question 17

What is the left ventricular diastolic pressure?

Answer 17

6 mmHg

Question 18

What is the pulmonary artery pressure?

Answer 18

25/10 mmHg

Question 19

What is the pulmonary wedge pressure?

Answer 19

6 mmHg

Question 20

What is the mean brachial artery pressure?

Answer 20

95 mmHg

Question 21

What is the mean central venous pressure?

Answer 21

5 mmHg

Question 22

Is the intrathoracic or extra thoracic venous pressure greater?

Answer 22

Extrathoracic

Question 23

Why is the extra thoracic venous pressure greater than the intrathoracic pressure?

Answer 23

The blood is coming off of the arteries which have a higher pressure than the CVP which is in the intrathoracic cavity.

Question 24

What effect does aortic stenosis have on aortic arterial pressure?

Answer 24

The aortic arterial can actually decrease due to the stenosis creating a larger pressure gradient.

Normal is 120/80 -> 110/75

Question 25

What effect does aortic stenosis have on left ventricular pressure?

Answer 25

The after load would have a massive increase and it would go up to 220/10 from the normal 115/5

Question 26

What effect does aortic stenosis have on pulmonary artery pressure?

Answer 26

It would only have a slight increase from 25/10 to 30/18

Question 27

What effect does aortic stenosis have on the central venous pressure?

Answer 27

Largely unchanged

Question 28

What effect does aortic stenosis have on heart rate?

Answer 28

It would increase the heart rate slightly going from a normal 72 to 84 due to the increased after load reduction the cardiac output. Baroreceptor reflex.

Question 29

What effect does aortic valve stenosis have on the left atrial pressure?

Answer 29

It is mostly unchanged going from 6 to 12.

Question 30

What effect does mitral valve stenosis have on arterial pressure?

Answer 30

It will decrease the arterial pressure from normal to 84/52 due to causing problems with preload.

Question 31

What effect does mitral valve stenosis have on left ventricular pressure?

Answer 31

LV pressure would decrease, especially systolic pressure, going to 87/5 because of the preload decreasing.

Question 32

What effect does mitral valve stenosis have on pulmonary artery pressure?

Answer 32

It would increase it drastically due to the mitral valve stenosis causing a back up into the artery and possibly resulting in pulmonary edema. Pressure would go to 40/30

Question 33

What effect does mitral valve stenosis have on central venous pressure?

Answer 33

It would be largely unchanged

Question 34

What effect does mitral valve stenosis have on heart rate?

Answer 34

Heart rate would increase in order to compensate for decreased preload.

Question 35

What effect does mitral valve stenosis have on left atrial pressure?

Answer 35

It would increase it due to the backup because of the mitral valve stenosis. It would go from being around 6 to 30.

Question 36

What effect does a decrease in venous return have on arterial pressure?

Answer 36

Arterial pressure would decrease slightly but it is well tolerated. Goes to 90/50

Question 37

What effect does a decrease in venous return have on pulmonary arterial pressure?

Answer 37

Goes to 16/8. Small change

Question 38

What effect does a decrease in venous return have on central venous pressure?

Answer 38

It would decrease significantly, falling to -2 as the veins are collapsing due to the negative pressure.

Question 39

What effect does a decrease in venous return have on heart rate?

Answer 39

Heart rate would increase in order to attempt to increase cardiac output back up to normal levels

Question 40

What effect does an increase in systemic vascular resistance have on arterial pressure?

Answer 40

It will increase both the systolic and diastolic pressure, but will increase diastolic more.

Question 41

What effect does an increase in systemic vascular resistance have on pulmonary arterial pressure?

Answer 41

It remains largely unchanged

Question 42

What effect does an increase in systemic vascular resistance have on CVP?

Answer 42

Remains unchanged

Question 43

What effect does an increase in systemic vascular resistance have on heart rate?

Answer 43

Heart rate will decrease to 45 in response to the increased pressures.

Question 44

What effect does sinus tachycardia have on the arterial and pulmonary pressures and the heart rate?

Answer 44

Heart rate increases to 120 Pulmonary Arterial Pressure has slight increase to 28/18 Arterial pressure decreases due to increased HR to 110/64

Question 45

What effect does ventricular tachycardia have on the arterial and pulmonary pressures and the heart rate?

Answer 45

HR increases to 151 PAP increases to 24/20 Arterial Pressure decreases to 82/60 due to increased HR

Question 46

What effect does ventricular fibrillation have on the arterial and pulmonary pressures and the heart rate?

Answer 46

HR 0 PAP 18/18 Arterial Pressure 19/19 - this is the mean circulatory pressure CVP 18 - increases as blood pools in the central venous pool

Question 47

What effect does atrial fibrillation have on the arterial and pulmonary pressures and the heart rate?

Answer 47

HR 120 - HR is determined by AV node refractory period PAP - unchanged at 25/15 Arterial Pressure is slightly decreased at 100/60 due to increased HR