As the volume of blood in the ventricles of the heart increases, with all other factors constant, stroke volume increases till a point. Explain why. (5)

Define stroke volume as the volume of blood expelled by the left ventricle into the aorta per contraction of the heart.Idea that as blood volume in the ventricle increases, this stretches the sarcomeres of cardiac muscle.Idea this increased sarcomere stretch removes mechanical interference and/or allows more actin-myosin cross bridges to form.Each cross-bridge generates a unit force; with more cross-bridges, a greater force is generated per contraction of the ventricle.A greater force of contraction leads to a greater volume of blood being expelled per contraction (hence the increased stroke volume).

Answered by Azmaeen Z. Biology tutor

1998 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Explain the formation of an action potential.


What is the structure of a protein?


How do I get full marks for this question "Describe how a vaccination leads to antibody production" ?


Nitrates and phosphates from fertiliser applied to crops may enter ponds and lakes. Explain how nitrate may cause the death of fish in fresh water.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences