What events occur during the cardiac cycle?

Within the heart the atria contract creating a high pressure and squeezing blood into the ventricles. The semi lunar valves are closed so pressure within the ventricles builds up.Pressure within the ventricles becomes greater than in the atria which closes the atrioventricular valves. The cardiac muscle of the ventricle walls contract which causes the pressure in the ventricles to exceed the pressure within the atria and pulmonary artery forcing the semi lunar valves to open and expelling blood from the heart.

JH
Answered by James H. Biology tutor

11298 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

How do signals cross a synapse


How can a child have cystic fibrosis when neither of the parents have the disorder? (5 Marks)


What are the main differences between RNA and DNA molecules?


How do Beta Cells secrete insulin to decrease blood glucose concentration?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning