Which statement best describes the planes of movement in the vestibular system?

Which statement best describes the planes of movement in the vestibular system?

• A. They are parallel
• B. They are orthogonal at 90 degrees
• C. They are at random angles
• D. They are at 45-degree increments

Answer: (B)

The vestibular system uses three semicircular canals arranged in three mutually perpendicular planes, forming a right-angle (orthogonal) coordinate system. This setup lets the system detect angular motion around three independent axes: horizontal, and the two vertical planes. When the head rotates, endolymph moves within the canal corresponding to that axis, bending hair cells in the ampulla and signaling the rotation. Because the planes are perpendicular to each other, each axis is encoded separately, providing clear, 3D orientation signals. That’s why the statement describing planes as orthogonal at 90 degrees is the best fit.

The vestibular system uses three semicircular canals arranged in three mutually perpendicular planes, forming a right-angle (orthogonal) coordinate system. This setup lets the system detect angular motion around three independent axes: horizontal, and the two vertical planes. When the head rotates, endolymph moves within the canal corresponding to that axis, bending hair cells in the ampulla and signaling the rotation. Because the planes are perpendicular to each other, each axis is encoded separately, providing clear, 3D orientation signals. That’s why the statement describing planes as orthogonal at 90 degrees is the best fit.