Your semicircular canals are three tiny, fluid-filled tubes in your inner ear that help you keep your balance. When your head moves around, the liquid inside the semicircular canals sloshes around and moves the tiny hairs that line each canal.

What movement do the semicircular canals detect?

The semicircular canals detect angular acceleration/deceleration of the head. There are three canals, corresponding to the three directions of movement, so that each canal detects motion in a single plane.

What does semicircular canal mean?

: any of three loop-shaped tubular parts of the inner ear that are filled with a watery fluid, are positioned at nearly right angles to each other, and play a role in the maintenance of balance and stabilization by detecting rotations or angular movements of the head.