Plain English Meaning

Tiny bulb-shaped chambers in the inner ear that sense when your head turns or tilts. They are the part of the balance system that tells your brain you are rotating.

Full Definition

Small fluid-filled sac-like structures at the base of each semicircular canal in the inner ear. Each ampulla contains sensory hair cells that detect movement of the fluid (endolymph) inside the canal, allowing the brain to sense angular acceleration of the head — pitch, roll, and yaw motions.

Context Anchor

Seen in instrument flying discussions of the ears, balance, and spatial disorientation.