Cardiac cycle

Question 1

What happens during a refractory period? when does it occur?

Answer 1

the membrane is less responsive to another action potential; during an action potential

Question 2

In skeletal muscle cells, action potentials result in what?

Answer 2

release of calcium ions

Question 3

what kind of action potentials do skeletal muscle fibers and cardiac muscles have?

Answer 3

skeletal = fast cardiac = long

Question 4

one contraction and one relaxation of the heart

Answer 4

heartbeat

Question 5

term for contraction

Answer 5

systole

Question 6

term for relaxation

Answer 6

diastole

Question 7

At resting heart rate, what lasts longer? systole or diastole?

Answer 7

diastole

Question 8

valves between the ventricles and adjacent arteries

Answer 8

semilunar valves

Question 9

what drives blood flow?

Answer 9

systole and diastole - altering blood pressure to create pressure gradients

Question 10

what opens and closes the heart valves?

Answer 10

pressure differences

Question 11

when do the AV valves open and close?

Answer 11

open when press is higher in atria than ventricles; close when press is lower in atria than ventricles

Question 12

when do the semilunar valves open and close?

Answer 12

open when press is higher in the ventricles than the atria; close when pressure is higher in arteries than ventricles

Question 13

events that occur within the heart during one heartbeat

Answer 13

cardiac cycle

Question 14

what are the 4 phases of the cardiac cycle?

Answer 14

1. ventricular filling
2. isovolumetric contraction
3. ventricular ejection
4. isovolumetric relaxation

Question 15

when does ventricular systole occur during the cardiac cycle?

Answer 15

phases 2 and 3

Question 16

when does ventricular diastole occur during the cardiac cycle?

Answer 16

phases 1 and 4

Question 17

when does atrial systole occur during the cardiac cycle? when are they in diastole?

Answer 17

at the end of phase 1 (very short); in diastole the rest of the cycle