What is the septum of the heart?

The wall between the heart chambers is called the septum of the heart. Gray's Anatomy (1918) describes it as a muscular wall that divides the heart into left and right sides.

What it is

  • A muscular wall that divides the heart into left and right sides.
  • Has an upper part (interatrial septum) between the atria and a lower part (interventricular septum) between the ventricles.
  • Prevents mixing of oxygenated and deoxygenated blood.

Where it is

  • In the middle of the heart.
  • Runs from the base of the heart to the apex.
  • The interventricular part is much thicker than the interatrial part.

Source:

Last verified: 2026-07-18

  • Best Anatomy Answers is an educational reference about human anatomy. It is not medical advice — for any health concern, talk to a licensed medical professional.

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