Cardiac Cycle and Sounds

Question 1

why does atrial pressure increase during ventricular systole?

Answer 1

blood continues to return to the heart but cannot move into the ventricles

Question 2

what is the diastolic pressure in the ventricles?

Answer 2

close to 0

Question 3

what is the ventricular volume at the beginning of the atrial contraction?

Answer 3

around 100-120 mL

Question 4

when does the aortic pressure decrease?

Answer 4

it is decreasing through atrial contraction and even into ventricular contraction

Question 5

what happens when the ventricular pressure in the ventricles exceed the atrial pressure?

Answer 5

the AV valves close

Question 6

what is the period known as isovolumetric contraction?

Answer 6

the ventricular volume remains constant while the ventricular pressure increases dramatically

Question 7

what dictates what pressure the ventricle must exceed before the aortic valve opens?

Answer 7

the diastolic pressure

Question 8

when do the aortic and pulmonary valves close?

Answer 8

when the pressure in the ventricles drop below the arterial pressure

Question 9

at the point of divergence between the aortic pressure and the ventricular pressure, what happened?

Answer 9

closure of the aortic valve and pulmonary valve

Question 10

the closing of the aortic valve produces what in the aortic pressure wave?

Answer 10

the dicrotic notch

Question 11

what is isovolumetric relaxation?

Answer 11

no blood enters or leaves the ventricle while it is relaxing because both the AV and aortic valves are closed- all the valves are closed, blood can’t get in

Question 12

what happens when the atrial pressure exceeds the ventricular pressure?

Answer 12

the AV valves will open

Question 13

why does the aortic pressure continue to drop during atrial systole and ventricular diastole?

Answer 13

the blood is leaving the aorta and flowing into the smaller vessels in the periphery

Question 14

what is the rate of the peripheral run-off determined by?

Answer 14

the resistance to blood flow

Question 15

What is the a wave created by?

Answer 15

atrial contraction

Question 16

why is the jugular pressure clinically important?

Answer 16

bc if blood starts to back up due to the heart’s inability to pump blood- the jugular pressure will be affected very early

Question 17

what is the c wave created by?

Answer 17

isovolumetric contraction of the ventricles- the AV valves that are closed bulge back into the atria

Question 18

what is the v wave created by?

Answer 18

blood returning back to the atria

Question 19

what is the first heart sound (S1) associated with?

Answer 19

closure of the AV valves- blood in the atria hitting the closed valves as it tries to enter the ventricle

Question 20

what is the second heart sound (S2) associated with?

Answer 20

closing of the aortic and pulmonary valves- blood in the aorta/pulmonary artery back flows and bounces off the closed valves

Question 21

what is the third heart sound (S3) associated with?

Answer 21

blood rushing into the ventricle during the rapid filling phase

Question 22

when is the fourth heart sound heard?

Answer 22

during atrial contraction - before the first heart sound

Question 23

what is the fourth heart sound the result of?

Answer 23

the last little bit of blood squeezing into the ventricle

Question 24

when is a murmur heard (2 reasons)?

Answer 24

blood is moving in a direction it shouldn’t be moving or blood is having a hard time moving in the direction it should be moving in

Question 25

what is blood moving in a direction it shouldn’t associated with?

Answer 25

an incompetent valve (aka regurgitation)

Question 26

what is blood having a hard time moving in the direction it should be moving associated with?

Answer 26

a valve is open but not fully–> open valve stenosis

Question 27

when might you hear a systolic murmur when blood is moving in a direction it shouldn’t be moving?

Answer 27

when blood moves back into the atria caused by regurgitation

Question 28

when might you hear a systolic murmur when blood is having a hard time moving in the direction it should be moving in?

Answer 28

blood can’t get into the aorta/pulmonary artery due to stenosis

Question 29

when might you hear a diastolic murmur when blood is moving in a direction it shouldn’t?

Answer 29

when blood is moving back from the aorta into the ventricle

Question 30

when might you hear a diastolic murmur when blood is having a hard time moving in the direction it should be moving?

Answer 30

when blood can’t get into the ventricle due to stenosis