NREMT Paramedic

Answer: A - The aortic valve prevents regurgitation of blood back into the left ventricle during the diastolic phase because it is located between the left ventricle and aorta. This event is often confused with the other valves of the heart. The tricuspid valve prevents blood from flowing back up into the right atrium during contractions of the right ventricle. Likewise, the mitral valve prevents blood flow back into the left atrium during contraction of the left ventricle. The pulmonic valve is similar to the aortic valve; it prevents blood flow back into the right ventricle from the pulmonary arteries during diastole.