What are the two types of heart valves?

What are the two types of heart valves?

• A. Atrioventricular valves (AV) and semilunar valves (SL)
• B. Valves of the heart are all identical
• C. Only AV valves exist in the heart
• D. Valves do not exist in the heart

Answer: (A)

Two main categories of heart valves control one-way blood flow: atrioventricular valves and semilunar valves. The atrioventricular valves sit between the atria and ventricles (the mitral and tricuspid valves) and prevent blood from flowing backward into the atria when the ventricles contract. The semilunar valves are located at the exits of the ventricles into the great arteries (the aortic and pulmonary valves) and prevent blood from flowing back into the ventricles when the arteries recoil after blood is ejected. Recognizing these two types emphasizes that valves are organized by their location and role in directing flow, not by being identical. There are four valves in the heart in total (two AV and two semilunar), so statements claiming all valves are identical or that valves don’t exist aren’t accurate.

Two main categories of heart valves control one-way blood flow: atrioventricular valves and semilunar valves. The atrioventricular valves sit between the atria and ventricles (the mitral and tricuspid valves) and prevent blood from flowing backward into the atria when the ventricles contract. The semilunar valves are located at the exits of the ventricles into the great arteries (the aortic and pulmonary valves) and prevent blood from flowing back into the ventricles when the arteries recoil after blood is ejected. Recognizing these two types emphasizes that valves are organized by their location and role in directing flow, not by being identical. There are four valves in the heart in total (two AV and two semilunar), so statements claiming all valves are identical or that valves don’t exist aren’t accurate.