In what age group are the right and left ventricles equal in weight and muscle mass?
A) Newborns
B) School-age children
C) Adolescents
D) Older adults

Question

Quizplus · Accepted Answer

At the time of birth, the right and left ventricles are equal in weight and muscle mass because they both pump blood into the systemic circulation. Within 24 to 48 hours, closure of the ductus arteriosus and interatrial foramen ovale causes pressure in the left atrium to increase. At this time, the right ventricles demand changes as the pulmonary circulation develops, and the left ventricle assumes total responsibility for providing systemic circulation. This results in an increase in the mass of the left ventricle. In older adults, the left ventricle wall thickens and the valves become fibrotic and calcified. The right and left ventricles are not equal in weight and muscle mass in school-age children, adolescents, or older adults.

In What Age Group Are the Right and Left Ventricles