Final answer:
The four principal functions of heart valves are ensuring unidirectional blood flow, preventing backflow, maintaining pressure gradient, and enabling efficient pumping. These valves include the tricuspid valve, pulmonary valve, mitral valve, and aortic valve.
Step-by-step explanation:
The four principal functions of valves in the heart are as follows:
Unidirectional blood flow: Valves ensure that blood flows in only one direction through the heart.Preventing backflow: They prevent blood from flowing backward into the atria or ventricles.Maintaining pressure gradient: By opening and closing at precise times, valves help maintain the pressure gradient necessary for the circulation of blood.Efficient pumping: Valves enable the heart to pump blood efficiently to the lungs and the rest of the body by coordinating the timing of muscle contractions and relaxations.The four heart valves are the tricuspid valve, pulmonary valve, mitral (or bicuspid) valve, and aortic valve.