MICROANATOMY

BLOOD CARDIOVASCULAR SYSTEM LYMPHOID ORGANS

CARDIOVASCULAR SYSTEM

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What prevents blood from flowing back into the atria when the ventricles contract?
A
semilunar valves
B
sinoatrial node
C
atrioventricular node
D
tricuspid and bicuspid valves
Explanation: 

Detailed explanation-1: -The valves prevent the backward flow of blood. Valves are actually flaps (leaflets) that act as one-way inlets for blood coming into a ventricle and one-way outlets for blood leaving a ventricle. Normal valves have 3 flaps (leaflets), except the mitral valve. It only has 2 flaps.

Detailed explanation-2: -Tricuspid valve: Allows blood to pass from the right atrium to the right ventricle; prevents blood from flowing back into the right atrium as the heart pumps (systole).

Detailed explanation-3: -The tricuspid valve prevents backflow from the right ventricle into the right atrium. The bicuspid valve prevents backflow from the left ventricle into the left atrium. The semilunar valves prevent backflow into the ventricles from the aorta and pulmonary arteries.

Detailed explanation-4: -Tricuspid valve: This valve has three leaflets. They allow blood to flow from the right atrium to the right ventricle. They also prevent blood from flowing backward from the right ventricle to the right atrium.

There is 1 question to complete.