Myocardial blood flow to the left ventricle increases during (T/F )
a. Eary systole
b. Myocardial hypoxia
c. Adenosine infusions
d.Stimulation of sympathetic nerves to the heart
e.Arterial hypertension
Answer
a. F
b.T
c.T
d.T
e.T
Discussion
a. Coronary vessels are compresed by the contracting myocardium
b. A fall in Po2 has a potent effect on coronary vessels
c. Adenosine released from hypoxic myocardium is also a potent vasodilator
d. Sympathetic stimulation increse the rate force of contraction:, the resulting increse in the rate of production of vasodilatror metabolites dilates coronary vessels
e.Myocardial work and metabolisam are incresed in hypertension
Labels: CVS, CVS MCQ, Physiology MCQ