Cardiac Muscle

Question 1

Atrioventricular valves prevent back flow from _________ to _________ during ________

Answer 1

ventricles; atria; systole

Question 2

Atrioventricular valves include:

Answer 2

Tricuspid and Bicuspid/mitral

Question 3

Closure of the AV valves = the ______ heart sound

Answer 3

1st

Question 4

Semilunar valves prevent backflow from _________ to ________ during _________

Answer 4

arteries; ventricles; diastole

Question 5

Closure of the semilunar valves = the _______ heart sound

Answer 5

2nd

Question 6

Heart sounds are the sound of turbulent blood flow through the valves right _________ they close

Answer 6

BEFORE

Question 7

Stenosis means the valves are _______

Answer 7

narrow/rigid

Question 8

Regurgitation means the valves do not _______ correctly

Answer 8

close

Question 9

Action potentials in contractile cardiac muscle last ______ longer than skeletal muscle’s AP

Answer 9

15x

Question 10

Action potential phases:
- 4:
- 0:
- 1:
- 2:
- 3:

Answer 10

• 4: at rest
• 0: rapid depolarization - upstroke
• 1: repolarization (brief)
• 2: plateau due to balance between Ca2+ & K+ currents
• 3: repolarization

Question 11

Na is important for _______ ________

Answer 11

rapid depolarization

Question 12

Ca functions to _______ length of AP and helps with contraction of the heart

Answer 12

prolong

Question 13

K is important for _________

Answer 13

repolarization

Question 14

In an _________ ________ ________, it is impossible to fire another AP

Answer 14

absolute refractory period (ARP)

Question 15

A(n) _________ ________ _________ is unable to have a functionally effective AP

Answer 15

Effective refractory period

Question 16

Effective refractory period (ERP) lasts the length of _______ and then a tiny bit more

Answer 16

absolute refractory period (ARP)

Question 17

An effective refractory period (ERP) can fire AP in an indiv. cell but CANT ___________ ____ ______ ____

Answer 17

ripple to next one

Question 18

The long absolute refractory period (ARP) of cardiac myocytes is vital physiologically because it allows the heart to fill with blood and prevents ________ _________ of cardiac contraction

Answer 18

temporal summation

Question 19

Relative refractory period (RRP) can get an AP only with a large enough __________

Answer 19

depolarization

Question 20

Supranormal period (SNP) is from end of ______ to end of ______

Answer 20

relative refractory period (RRP); AP

Question 21

Period when:
- Easier to fire an AP than rest

• All VG Na channels are back at rest and Vm is depolarized, so don’t need much of a stimulus

Answer 21

Supranormal Period (SNP)

Question 22

If you fire an AP during RRP or SNP, contraction will be incredibly ________ and not much blood will be ejected.

Answer 22

weak

Question 23

There is a relationship between the length of APs in cardiac contractile & skeletal m. cells, and the length of __________

Answer 23

contraction/relaxation

Question 24

Refractory period of cardiac muscle lasts almost the entire legnth of the cardiac muscle twitch. This allows time for _______ _______

Answer 24

cardiac filling