Flow Of Blood

Question 1

What happens in the atrial systole

Answer 1

Muscles of atria contract
The tricuspid and bicuspid valves are forced open to allow blood to flow from atria into ventricles
In 0.1 seconds

Question 2

What happens in ventricular systole

Answer 2

Muscles if the ventricles contract
Both tricuspid and bicuspid valves close
Semilunar valves of pulmonary artery and aorta open
Deoxyhenated blood from the right ventricle is forced up the pulmonary artery and moves to lungs
Oxygenated blood from left ventricle is forced up the aorta and moves to all parts of the body
Takes 0.3 seconds

Question 3

Atrial and ventricular diastole

Answer 3

Muscles of the aorta and ventricles relax
Semilunar valves in aorta and pulmonary artery close to prevent back flow
Deoxygenated blood from vene cavae fills right atrium
Oxygenated blood from pulmonary veins fills left atrium
Cycle starts again
Takes 0.4 seconds