571. “COO wave of the JVP occurs during:
A. Atrial contraction
B. Beginning of ventricular systole
C. End of ventricular systole
D. Isovolumic relaxation
E. None of the above

572. Which of the following statement is FALSE?
A. 70% of ventricular emptying occurs in the 1st 1/3 of the period of ejection
B. 30% of ventricular emptying occurs in the latter 2/3 of the period of ejection
C. Atrial contraction occurs at the last 1/3 of the ventricular diastole
D. Normal ejection fraction is about 50%
E. When the heart contracts strongly, end systolic volume may reduce to 10-20m!.

573. Which of the following statement is CORRECT?
A. Contraction of papillary muscle causes mitral & tricuspid valves to close.
B. Papillary muscles contract independently to the remainder of myocardium
C. Aortic & pulmonary valves are not attached to papillary muscle or chordae tendinae
D. All of the above
E. None of the above

574. Regarding cardiac output:
A. Baseline sympathetic outflow maintains cardiac output 30% higher than that of the denervated heart.
B. Strong vagal stimulation can reduce cardiac output by 50%.
C. Duration of systole shortens during increased sympathetic outflow
D. All the above are false
E. All the above are true

575. Bradycardia occurs with:
A. Hypercalcaemia
B. Hypematraemia
C. Hyperkalaemia
D. Hyperthermia
E. All of the above

576. Regarding prepotential:
A. Its low resting membrane potential is due to a moderate amount of sodium channels being open at rest.
B. It is initiated by opening of sodium channels
C. It’s slope is increased by increased vagal tone
D. It’s slope is reduced by increased sympathetic tone
E. All of the above are true

577. A V nodal delay is:
A. 0.03 seconds
B. 0.06 seconds
C. 0.09 seconds
D. 0.12 seconds
E. 0.15 seconds II.

578. The following part of the circulation holds the largest percentage of total blood volume
A. Heart
B. Pulmonary circulation
C. Arteries
D. Capillaries
E. Veins

579. The following part of the circulation has the largest cross sectional area:
A. aorta
B. arteries
C. capillaries
D. venules
E. veins

580. Regarding Blood flow in the capillary:
A. It is continuous
B. Viscosity decreases along the length of the capillary
C. Velocity is constant along the length of the capillary
D. It displays the Fahraeus-Lindquist effect.
E. All of the above