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Electrical System of the Heart - Topic Overview

How does your body control your heart rate?

Your body controls your heart by:

  • The sympathetic and parasympathetic nervous systems, which have nerve endings in the heart.
  • Hormones, such as epinephrine and norepinephrine (catecholamines), which circulate in the bloodstream.

Sympathetic and parasympathetic nervous systems

The sympathetic and parasympathetic nervous systems are opposing forces that affect your heart rate. Both systems are made up of very tiny nerves that travel from the brain or spinal cord to your heart. The sympathetic nervous system is triggered during stress or a need for increased cardiac output and sends signals to your heart to increase its rate. The parasympathetic system is active during periods of rest and sends signals to your heart to decrease its rate.

Catecholamines

During stress or a need for increased cardiac output, the adrenal glands release a hormone called norepinephrine into the bloodstream at the same time that the sympathetic nervous system is also triggered to increase your heart rate. This hormone causes the heart to beat faster, and unlike the sympathetic nervous system that sends an instantaneous and short-lived signal, norepinephrine released into the bloodstream increases the heart rate for several minutes or more.

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WebMD Medical Reference from Healthwise

Last Updated: March 07, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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