The Cardiac Cycle

Question 1

Transition from rest to exercise:

Answer 1

Diastole is shortened during exercise

Question 2

Diastole

Answer 2

Relaxation Period> Filling; ⅔ of the time at rest

Question 3

Systole

Answer 3

Contraction Phase> Ejection; ⅓ of the time at rest

Question 4

Phase 1

Answer 4

Ventricular Filling, AV valves open; Occurs during mid to late diastole; Atrial contraction pushes additional blood through

Question 5

Phase 2

Answer 5

Systole has two periods

Isovolumetric Contraction, AV Valves and Semilunar Valves Closed; Ventricular Ejection: Semilunar Valves Open

Question 6

Phases 3

Answer 6

Isovolumetric Relaxation

Both AV Valves and Semilunar Valves Closed

Question 7

What causes a heart attack?

Answer 7

Coronary Artery is blocked and myocardial walls are damaged; Causes inadequate oxygen and nutrients delivery and built up acidity by proton generation in myocardial wall; Cannot create electrical impulses for coordinated contraction

Question 8

What protects against heart attack?

Answer 8

Exercise training; Increases number of antioxidant enzymes that are available in the heart tissue and heat shock proteins; regularly trains the heart to tolerate reperfusion