When are the semilunar valves open?
Understand the Problem
The question is asking about the function of the semilunar valves in the heart, specifically when these valves are open during the cardiac cycle. This involves understanding the phases of the heartbeat and the roles of the semilunar valves in allowing blood flow into the arteries.
Answer
During ventricular contraction when ventricular pressure exceeds arterial pressure.
The semilunar valves are open during ventricular contraction when ventricular pressure exceeds arterial pressure.
Answer for screen readers
The semilunar valves are open during ventricular contraction when ventricular pressure exceeds arterial pressure.
More Information
During ventricular contraction, the increase in pressure forces the semilunar valves to open, allowing blood to flow into the aorta and pulmonary artery. This phase is crucial for the efficient ejection of blood from the heart.
Tips
Ensure to distinguish clearly between the contraction and relaxation phases of the cardiac cycle to avoid confusion about when the semilunar valves open and close.
Sources
- Biology Cardiac Cycle Info Sheet - montsaye.northants.sch.uk
- 17.2C: Operation of Semilunar Valves - Medicine LibreTexts - med.libretexts.org
- Semilunar valve | Anatomy, Function, & Diseases - Britannica - britannica.com
