How do electrical impulses control contraction of the heart?

Electrical impulses from the SAN (sinoatrial node) spread across the atria walls to cause contraction. The impulses then pass to the ventricles via the AVN (atrioventricular node) after a short delay to allow time for the atria to fully contract. These impulses then pass down the purkyne fibres to the heart apex. They then spread up through the ventricle walls to cause contraction from the apex upwards. Blood is squeezed into the arteries as a result.

JA
Answered by Jack A. Biology tutor

2417 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

What are the key principles of evolution?


Explain the sliding filament theory of muscle contraction


What is the structure of a protein?


Describe evolution by natural selection and how this may lead to speciation?


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