2 CVS - The Heart as a Pump

Question 1

What is systole?

Answer 1

Contraction and ejection of blood from ventricles

Question 2

What is diastole?

Answer 2

Relaxation of filling of ventricles

Question 3

What is the stroke volume?

Answer 3

The amount of blood pumped per beat. 70ml per beat

Question 4

An action potential causes a rise in intracellular ….?

Answer 4

Calcium

Question 5

What heart valve is on the right?

Answer 5

Tricuspid

Question 6

What heart valve is on the left?

Answer 6

Mitral

Question 7

What controls the opening and closing of valves?

Answer 7

The differential blood pressure on either side of it

Question 8

When atrial pressure is higher than ventricle pressure, what will happen?

Answer 8

the mitral and tricuspid valves will open?

Question 9

What do the cusps of the mitral and tricuspid valves attach to?

Answer 9

Attach to papillary muscles via chordae tendineae

Question 10

What are the seven phases of the cardiac cycle?

Answer 10

1 Atrial Contraction
2 Isovolumetric Contraction 
3 Rapid ejection
4 Reduced ejection 
5 Isovolumetric relaxation
6 Rapid filling
7 Reduced filling

Question 11

What phases are involved in systole?

Answer 11

2-4

Question 12

What effect does heart rate on systole and diastole?

Answer 12

Systole remains constant from beat to beat, the length of diastole varies with heart rate

Question 13

How long is systole?

Answer 13

0.35 seconds

Question 14

What is the A wave?

Answer 14

the rise in atrial pressure due to atrial systole

Question 15

How is the majority of ventricle filling achieved?

Answer 15

Passive diffusion

Question 16

What does the P wave on an ECG signify?

Answer 16

Onset of atrial depolarisation?

Question 17

What is on the X and Y axis of a wiggers diagram?

Answer 17

X axis is used to plot the time

Y axis is used to plot Aortic, Atrial and Ventricular pressure and ventricular volume and an ECG

Question 18

When does the mitral valve close?

Answer 18

As the intraventricular pressure exceeds the atrial pressure

Question 19

What happens to the ventricular volume during isovolumetric contraction?

Answer 19

No change in volume as all the valves are closed

Question 20

What happens to the ventricular pressure during isovolumetric contraction?

Answer 20

there is a rapid rise in ventricular pressure as it contracts

Question 21

What is responsible for the first hear sound? S1

Answer 21

Closure of the mitral and tricuspid valves, results in the first heart sound

Question 22

When does ventricular ejection begin?

Answer 22

When the intraventricular pressure exceeds the pressure within the aorta?

Question 23

What noise is the opening of the aortic valve responsible for?

Answer 23

None, ya dummy

Question 24

What is the X descent

Answer 24

During rapid ejection, the Atrial pressure is initially decreased as the atrial base is pulled downwards as the ventricle contracts. This is called the “X descent”

Question 25

What leads to a reduced rate of ejection?

Answer 25

Repolarization of the ventricles

Question 26

What is the V wave?

Answer 26

Atrial pressure gradually rises due to the continuous venous return. V wave = Venous return

Question 27

What is the dicrotic notch?

Answer 27

The graph of aortic pressure throughout the cardiac cycle displays a small dip which coincides with the aortic valve closure.

Question 28

What causes the aortic valve to close?

Answer 28

When the intra-ventricular pressure falls below the aortic pressure, there is a brief back-flow of blood which causes the aortic valve to close

Question 29

Closure of the aortic and pulmonary valves results in which heart sound?

Answer 29

S2

Question 30

What is the Y descent?

Answer 30

Fall in atrial pressure, that occurs after the opening of the mitral valve

Question 31

Sometimes there is a third heart sound, S3, what is the cause of this?

Answer 31

Ventricular filling

Question 32

At rest how full are the ventricles?

Answer 32

90%

Question 33

By the end of what phase can you calculate the EDV?

Answer 33

Atrial Contraction

Question 34

What are the two main causes of abnormal valve function?

Answer 34

Stenosis and regurgitation

Question 35

In simple terms what happens in valve stenosis?

Answer 35

The valve does't open enough leading to obstruction to blood flow when the valve is open

Question 36

What is regurgitation?

Answer 36

The valve doesn't open all the way, leading to back leakage when the the valve should be closed

Question 37

What are the causes of aortic valve stenosis?

Answer 37

Degenerative, congenital, chronic rheumatic fever

Question 38

What are the complications of aortic valve stenosis?

Answer 38

LV hypertrophy, syncope, angina, Microangipathic haemolytic anaemia

Question 39

What is microangiopathic haemolytic anaemia?

Answer 39

Loss of red blood cells through destruction, shear stress

Question 40

What happens to systolic and diastolic pressure in aortic valve regurgitation?

Answer 40

Systolic pressure increases, diastolic pressure decreases

Question 41

What is the main cause of mitral valve stenosis?

Answer 41

Rheumatic fever