Which semicircular canals detect angular acceleration?

• A. Horizontal (lateral), superior (anterior), and posterior semicircular canals
• B. Horizontal (lateral), superior (anterior), and inferior semicircular canals
• C. Anterior, posterior, and inferior semicircular canals
• D. Lateral, anterior, and inferior semicircular canals

Answer: (A)

Angular acceleration is detected by the semicircular canals as the head rotates, with each canal oriented in a different plane so that all three dimensions of head movement are covered. The horizontal (lateral) canal detects rotation around a vertical axis (yaw), the superior (anterior) canal detects rotation in the sagittal plane (pitch, like nodding), and the posterior canal detects rotation in the frontal plane (roll, like tilting the head toward the shoulder). Together, these three canals provide sensitivity to angular changes in all directions. In humans, there are three such canals per ear: horizontal, superior, and posterior. The inferior canal is not a separate canal in standard anatomy, so it isn’t part of the normal triad that detects angular acceleration. The mechanism involves endolymph movement the moment the head turns, which deflects the cupula in each ampulla and bends hair cells, generating signals to coordinate balance and eye movements.