Emergency Medical Technician (EMT) Intermediate Practice Exam

Which of the following valvular structures in the heart are known as atrioventricular (AV) valves?

1. Tricuspid and pulmonary

2. Pulmonary and mitral

3. Tricuspid and mitral

4. Aortic and mitral

The correct answer is: Tricuspid and mitral

Atrioventricular (AV) valves are crucial structures in the heart that serve to separate the atria from the ventricles, preventing backflow of blood during the cardiac cycle. The tricuspid valve, located between the right atrium and the right ventricle, features three leaflets that open and close to regulate blood flow. The mitral valve, situated between the left atrium and left ventricle, has two leaflets and functions similarly. These valves' primary role is to ensure that blood flows in only one direction: from the atria into the ventricles during diastole and prevent it from returning during systole. The identification of the tricuspid and mitral valves as the AV valves in the heart highlights their critical function in maintaining proper hemodynamics during each heartbeat. Other choices include valves that do not separate the atria from the ventricles, such as the aortic and pulmonary valves, which serve to prevent backflow of blood from the arteries into the ventricles but are not classified as AV valves. This distinction is essential for understanding the anatomy and function of the heart in both physiological and pathological contexts.