Question

When the left ventricle contracts, the ------ valve closes and the ------- valve is pushed open.

1) bicuspid; pulmonary

2) tricuspid; pulmonary

3) Right AV; aortic

4) Left AV; aortic

5) aortic; pulmonary

Answer 1

The ventricles contracts in 2 phases

1. Isovolumetric contraction- this is the point at which aortic ventricular valve closes(heard sound 1 appears) and ventricles are a closed chamber. the pressure inside the ventricle increases
2. ventricular systole proper. because of increased pressure inside the ventricle from contracting like a closed chamber the semilunar valves open. (aortic and pulmonary)

so the answer is 4.

when the left ventricle contracts the left atrio ventricular valve closes and pushes open the aortic valve.