Welcome to this tutorial of the Cardiac cycle. It is designed to guide you through learning about the processes involved in a heartbeat. It is essential that you read the material provided in lectures, however the key points discussed should provide you with the level of understanding required in the BMS201 course.

The Human Heart

This YouTube video describes the Cardiac Cycle by graphical representation. This will give you a good overview of the complete process of a heartbeat. We recommend watching this before looking through the key points we have provided on this site.

Did you know..? 

Your heart, on average, beats around 4200 times an hour, 100800 times a day and over 36 million times a year!

News

03/05/2010 09:28

Cardiac cycle - Sudden Cardiac Death in Sports

"In general, a lot of research has been done and a lot written about sudden cardiovascular death related to sport, but thanks to different outcomes of various studies, confusion still prevails about the exact definition of the condition, and indeed, what exactly causes it. Although, we know of...

Read more

—————

The information in this website was obtained from the recommended reading and some additional websites, all of which are listed in the introduction.

Banner picture and Heart diagram on this page were obtained from Wikimedia commens.

Overview

Overview of volume changes:

  • End-systolic volume = 60mL
  • Passively added to ventricles during atrial diastole = 30mL

Added by atrial systole = 40mL

  • Total (End-Diastolic Volume) = 130mL
  • Stroke Volume ejected by ventricular systole = 70mL

End-Systolic Volume = 60mL

The amount ejected by each ventricle in 1 minute is called the cardiac output. The cardiac output can be worked out by heart rate (beats/min) x stroke volume (L). The average person has a heart rate of 70 beats per min and a stroke volume of 70mL per beat, which gives a cardiac output of 4900mL per minute. A typical person has approximately 5L's of blood in their body. Therefore, according to our calculations, nearly the whole volume of blood passes through the heart every minute. Cardiac output is not constant and can increase or decrease depending on the body's activities.