Emergency Medical Technician (EMT) Intermediate Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the Emergency Medical Technician (EMT) Intermediate Test with focused study methods including flashcards and multiple-choice questions. Practice with hints and detailed explanations to boost your readiness for the exam.

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

How do the semilunar valves in the heart primarily function?

Allow blood flow into the atria
Prevent backflow of blood into the ventricles
Facilitate blood flow into the aorta
Control the flow of blood through the veins

The correct answer is: Prevent backflow of blood into the ventricles

The semilunar valves play a crucial role in the cardiovascular system by preventing the backflow of blood into the ventricles after it has been pumped out. Located at the exit of the right and left ventricles, these valves (the pulmonary and aortic valves) open to allow blood to flow into the pulmonary artery and aorta, respectively, during ventricular systole. Once the ventricles contract and eject blood, the pressure decreases as the ventricles relax. The semilunar valves close tightly to ensure that blood does not flow back into the ventricles during this phase, maintaining unidirectional blood flow and ensuring efficient circulation throughout the body. This function is vital to maintaining the pressure needed to push blood forward into the arteries without letting it flow backward, which could lead to complications such as decreased cardiac output and increased workload on the heart.