Cardiac Cycle

Question 1

Atrial Systole

Answer 1

contraction of right & left atria pushes blood into ventricle

Question 2

Atrial Dystole

Answer 2

period between atrial contractions when the atria are repolarizing

Question 3

Ventricular Systole

Answer 3

contraction of right & left ventricles pushing blood into the pulmonary arteries and aorta

Question 4

Ventricular Diastole

Answer 4

period between ventricular contraction when ventricles are repolarizing

Question 5

Preload

Answer 5

tension in ventricular wall at end of diastole- reflects venous filling pressure that fills left ventricle during diastole

Question 6

Afterload

Answer 6

forces that impede flow of blood out of heart, primarily pressure in peripheral vasculature, compliance of aorta, mass/viscosity of blood

Question 7

Stroke Volume (SV)

Answer 7

volume of blood ejected by each contraction of left ventricle
Normal= 60-80mL (depends on age/sex/activity level)

Question 8

Cardiac Output (CO)

Answer 8

amount of blood pumped from left/right ventricle per minute
CO= SVxHR
Normal Adult Male @ rest= 4.5-5.0L/min (Normal Adult Female is slightly less)
Can increase up to 25mL/min w/ exercise

Question 9

Venous Return

Answer 9

amount of blood that returns to right atrium each minute- similar in volume to CO
Venous Return MUST = CO when averaged over time due to closed loop system