For each of the valvular functions A–E, select the most appropriate option from the valves listed below

A. Option 2 Tricuspid valve. This valve closes when right ventricular pressure exceeds right atrial pressure and so prevents regurgitation of blood into the atrium when the right ventricle contracts.

B. Option 3 This valve, situated in the mouth of the aorta, closes during diastole when aortic pressure exceeds left ventricular pressure. Incompetence of this valve allows reflux of blood from the aorta back into the ventricle and increases the work of the heart to maintain the same cardiac output.

C. Option 1 Mitral valve. This valve closes when left ventricular pressure exceeds left atrial pressure and so prevents regurgitation of blood into the atria when the ventricle contracts. When disease results in valve incompetence, a systolic murmur may be heard over the heart.

D. Option 5 Pulmonary valve. This valve, situated in the mouth of the pulmonary artery, closes during diastole when pulmonary artery pressure exceeds right ventricular pressure.

E. Option 4 Foramen ovale valve. This valve closes the foramen ovale in the inter-atrial septum when return of blood in the pulmonary veins raises left atrial pressure above right atrial pressure.