Cardiac Cycle

Question 1

WD Phase A

Atrial Systole

Answer 1

• atria contract
• final phase of ventricular filling
• associated with 4th heart sound
• atrial pressure is reflected back to veins causing venous pressure “a” wave

Question 2

WD Phase B

Isovolumetric Ventricular Contraction

Answer 2

• ventricles contract
• ventricular pressure increases
• AV valves close
• produces 1st heart sound
• increased pressure causes bulge of AV valve into aorta, causing atrial “c” wave

Question 3

First Heart Sound

Answer 3

• closing of mitral and tricuspid (AV) valves
• ventricular contraction causes theses to close
• prevents blood from backing into atria
• onset of ventricular systole

Question 4

WD Phase C

Rapid Ventricular Ejection

Answer 4

• ventricles contract
• pressure increases and reaches max
• aortic valve opens
• blood ejected into arteries
• aortic pressure increases and reaches max

Question 5

WD Phase D

Reduced Ventricular Ejection

Answer 5

• ventricles eject blood into aorta at slower rate
• ventricles do not empty completely
• aortic pressure begins to fall

Question 6

End-Diastolic Volume

Answer 6

ventricular volume after filling

Question 7

Afterload

Answer 7

pressure against which the heart pumps blood into the circulation

Question 8

End-Systolic Volume

Answer 8

the amount of blood remaining in the ventricle at the end of systole

Question 9

Ejection Fraction

Answer 9

the proportion of EDV that is ejected

SV/EDV

Question 10

WD Phase E

Isovolumetric Relaxation

Answer 10

• ventricles relaxed
• ventricular pressure decreases
• aortic valves closed
• second heart sound
• volume is constant (ESV)
• atrial pressure increases due to venous return (“v” wave)

Question 11

Second Heart Sound

Answer 11

• semilunar valves closing
• pressure from ventricle and aorta
• when pressure of aorta is greater, the valves are pushed closed
• onset of ventricular diastole

Question 12

WD Phase F

Rapid Ventricular Filling

Answer 12

• ventricles relaxed
• AV valves open
• ventricle fills with blood
• volume increases
• ventricular pressure low
• may produce third heart sound

Question 13

WD Phase G

Rapid Ventricular Filling

Answer 13

• ventricles relaxed

- final phase of ventricular filling

Question 14

Lub-whistle-dup

Answer 14

• stenotic semilunar valve

- systolic timing

Question 15

Lub-dup-whistle

Answer 15

• stenotic AV valve

- diastolic timing

Question 16

Lub-swish-dup

Answer 16

• insufficient AV valve

- systolic timing

Question 17

Lub-dup-swish

Answer 17

• insufficient semilunar valve

- diastolic timing

Question 18

Stenotic Valve

Answer 18

• stiff, narrow valve that does not open completely
• blood must be force through at high velocity
• produces whistling sound

Question 19

Insufficient Valve

Answer 19

• valve cannot close completely
• blood flows backwards and collides with the blood moving forward
• produces swishing sound