How the pacemaker transmits electrical impulses through the heart

How the pacemaker transmits electrical impulses through the heart

Specialized cardiac muscle cells generate electrical impulses in the heart.
Encyclopædia Britannica, Inc.
  • © Behind the News (A Britannica Publishing Partner)
    Why not all people perceive colors the same way.
  • Time-lapse video, by Dutch photographer Frans Hofmeester, of his daughter from birth to age 12.
  • Encyclopædia Britannica, Inc.
    An MIT study compared brain connectivity between people writing essays using Chat GPT, a search engine, or only their own brain.
    Media Editor: Casey Mendoza
  • Encyclopædia Britannica, Inc.
    In a circuit through the cardiovascular system, red blood cells transport oxygen from the lungs to the body tissues and carry carbon dioxide from the body tissues back to the lungs.
  • Encyclopædia Britannica, Inc.
    The vascular system is a network of arteries, veins, and capillaries that supplies blood to the tissues of the body.
  • Encyclopædia Britannica, Inc.
    Bright swarms of Daphnia serve as the food source of many larger animals. The internal processes of Daphnia are easily studied through its transparent carapace. A single eye, sensitive to light, causes Daphnia to react in a sunlit river.
  • Encyclopædia Britannica, Inc.
    The heart, located between the lungs, powers the circulatory system.

Transcript

NARRATOR: Some cardiac muscle cells can generate and carry electricity better than others. They initiate and channel the dominant electrical impulse.

They form a kind of electrical wiring pattern throughout the cardiac muscle.

The largest concentration of these specialized cells is located in the right atrium. It's called the pacemaker.

It acts like a spark plug to begin each heartbeat, stimulating the muscles in the atria to contract, and setting off a second concentration of cells, which stimulates the ventricles to contract.

The electrical impulses from your heart can be detected on your skin by sensitive electrodes. These tiny electrical impulses are transmitted to an electrocardiograph machine.