Cardiac Cycle & Sounds

Question 1

Systole

Answer 1

The contraction of the heart. It can be divided into atrial systole (the atria are contracting) and ventricular systole (the ventricles are contracting)

Question 2

Diastole

Answer 2

The relaxation of the heart. It’s common to refer to ventricular diastole, but the atria do relax too

Question 3

Blood pressure is therefore shown as two numbers- the systolic pressure (the pressure ___________________) and the diastolic pressure (the pressure __________________). It is always written as _________________/_________________

Answer 3

During contraction
At the end of diastole
Systolic
Diastolic

Question 4

Three phases of ventricular systole

Answer 4

1. Isovolumic/isovolumetric contraction
2. Ventricular contraction
3. Ventricular ejection

Question 5

Both _______ and __________ can generate spontaneous action potentials

Answer 5

SA node

AV node

Question 6

Under normal conditions, the ___________ is fastest and serves as the normal pacemaker for the heart

Answer 6

SA node

Question 7

When the SA node fires, the action potential is spread through the atria (_________________)

Answer 7

Gap junctions

Question 8

The _____________ receives the depolarization from the SA node via an ___________________________________

Answer 8

AV node

Internodal pathway

Question 9

The AV node is ________ to conduct the action potential to the _____________, so there is a very brief “pause”

Answer 9

Slow

Ventricle

Question 10

The ventricles are then __________________

Answer 10

Depolarize

Question 11

The ventricles will ___________________, but the _____________ to depolarize are the _____________ to repolarize

Answer 11

Repolarize
Last
First

Question 12

Since the atria depolarize first, they contract first-this ________________ the pressure in the atria

Answer 12

Increases

Question 13

Atrial pressure increases
AV valves are _____________, aortic and pulmonary valves are _____________
Ventricular pressure is _______________ than atrial pressure slightly

Answer 13

Open
Closed
Lower

Question 14

QRS complex on ECG
AV valves are ______________, aortic and pulmonary valves are _________________
Ventricular pressure is __________________________-no ejection at this point
___________________________ in atrial pressure

Answer 14

Open
Closed
Rising rapidly
Little increase

Question 15

ST segment on ECG
AV valves are ______________, aortic and pulmonary valves are ____________
Ventricular __________________
Ventricular pressure continues to _________ and ______________ is taking place
_____________ heart sound

Answer 15

Closed
Open
Ejection
Rise
Ejection
First

Question 16

The _____________ heart sound (“lub”) is associated with closure of the ______________ valves

Answer 16

First

AV

Question 17

What actually causes the heart sound during ventricular systole?

Answer 17

The sound is the result of blood in the atria hitting the closed valves as it tries to enter the ventricle. That impact creates a vibration in the cardiac tissue that can be heard

Question 18

The pressure in the ventricle must ________________ the pressure in the pulmonary artery and aorta before the valves leaving the ventricles will __________

Answer 18

Exceed

Open

Question 19

Normal aortic pressure

Answer 19

120/70

Question 20

Normal pulmonary artery pressure

Answer 20

25/15

Question 21

The ventricular pressure must exceed the ____________ pressure on each side to open the valve

Answer 21

Diastolic

Question 22

T wave on ECG
AV valves are ______________, aortic and pulmonary valves are ___________
Ventricular pressure begins to _______________, blood is still ejected until the aortic valve closes
Ventricular ___________________

Answer 22

Closed
Open
Decrease
Repolarization

Question 23

Diastole starts at heart sound _________
AV valves ______________, aortic and pulmonary valves are _______________
Ventricular pressure ________________ rapidly __________________________ atrial pressure, atrial pressure is gradually ________________ until AV valves _________

Answer 23

Two
Closed
Closed
Decreases
Falling below
Increasing
Open

Question 24

Period where blood doesn’t enter or exit the ventricles

Answer 24

Isovolumetric relaxation

Question 25

What produces the second heart sound?

Answer 25

When the blood in the aorta/pulmonary artery backflows and "bounces" off the closed valves

Question 26

When the atrial pressure _______________ the ventricular pressure, the AV valves will open, and blood will move from the _________ to the ______________

Answer 26

Exceeds Atria Ventricles

Question 27

Rapid Ventricular Filling AV valves ________________, pulmonary & aortic valves are ________________ Blood _____________________________

Answer 27

Open Closed Enters ventricle

Question 28

Venous pressure The ___________ wave is the pressure wave created by the atrial contraction Since there is no valve between the atria and great veins, the pressure is reflected backwards

Answer 28

A

Question 29

Venous pressure The ________ wave is the pressure wave created by the period of isovolumetric contraction in the ventricles-there is bulging of the wall back into the atria

Answer 29

C

Question 30

Venous pressure | The ________ wave is the pressure wave created as blood returns back to the heart but can't enter the ventricle

Answer 30

V

Question 31

Heart sound due to closure of the AV valves (which signifies the onset of isovolumic contraction immediately after the QRS complex)

Answer 31

First heart sound

Question 32

Arises from closure of the aortic and pulmonic valves at the end of ejection. It occurs near the end of the T wave and signifies the start of isovolumic relaxation

Answer 32

Second heart sound

Question 33

Occurs at the onset of rapid ventricular filling and is due to vibration of the ventricular wall

Answer 33

Third heart sound

Question 34

Occurs during atrial contraction and is due to vibration of the AV valve leaflets by blood flowing into the ventricle

Answer 34

Fourth heart sound

Question 35

What are the two causes of murmurs?

Answer 35

Blood moving in a direction it should not be moving | Blood having a hard time moving in the direction it should be moving in

Question 36

What are the two causes of systolic murmur?

Answer 36

Blood is moving in a direction it should not be moving-in this case, back into the atria, caused by regurgitation (mitral regurgitation) Blood is having a hard time moving in the direction it should be moving it-in this case the blood can not get into the aorta/pulmonary artery due to stenosis

Question 37

What are the two causes of diastolic murmur?

Answer 37

Blood is moving in a direction it should not be moving-in this case, back into the aorta or pulmonary artery, caused by regurgitation (aortic regurgitation) Blood is having a hard time moving in the direction it should be moving it-in this case the blood can not get into the ventricle due to stenosis