Healthcare Library

What makes your heart beat?

Let’s take a closer look inside the heart. The yellow objects are not nerves. They’re actually specialized cardiac muscle cells in the walls of the heart. Their job is to send signals to the rest of the heart muscle and cause a contraction. Together, this group of cells is called the Cardiac conduction system. The main components of the Cardiac conduction system are the SA node, AV node, Bundle of His, Bundle branches, and Purkinje fibers. Let’s follow a signal through the contraction process. The SA node starts the sequence by causing the atrial muscles to contract. That’s why doctors sometimes call it the anatomical pacemaker. From there, the signal travels to the AV node, through the Bundle of His, down the Bundle branches, and through the Purkinje fibers, causing the ventricles to contract. This signal creates an electrical current that can be seen on a graph called an Electrocardiogram, or EKG. Doctors us an EKG as a way of seeing how well the Cardiac conduction system works. Any changes to the EKG can mean serious problems.

What makes your heart beat?

Review Date: 5/20/2019

Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Animations

Browse All

Videos

Browse All

In-Depth Animations

Browse All

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.
Content is best viewed in IE9 or above, Firefox and Google Chrome browser.

ways to give

view all

news room

view all

healthcare library

view all
Event Calendar

Hunterdon Healthcare offers an array of educational events, including childbirth, healthy living and fitness classes.

LEARN MORE
Health and Wellness Centers

Where health and fitness meet to help you stay healthy at every age.

LEARN MORE
Heart & Vascular

Heart and Vascular Services Department brings world-class cardiovascular care to our community.

LEARN MORE