Question
Complete the following passage:
Valves function to prevent backflow of blood and maintain a unidirectional circulation of blood within the body. The (i)__________ valve separates the right atrium from the right ventricle whereas the (ii)_____________ valve separates the left atrium and left ventricle. The (iii)___________ valve prevents the backflow of deoxygenated blood from the pulmonary artery into the right ventricle while the (iv)__________ valve prevents the backflow from aorta into the left ventricle.