Which structure is primarily responsible for angular vestibulo-ocular reflex (VOR)?

The angular vestibulo-ocular reflex (VOR) is primarily mediated by the semi-circular canals. These canals are essential components of the vestibular system, which is responsible for detecting rotational movements of the head. When the head turns, the endolymph fluid within the semi-circular canals moves, causing the hair cells within these structures to be displaced. This displacement generates signals that are transmitted to the ocular motor nuclei in the brainstem.

As a result, the angular VOR generates compensatory eye movements that stabilize vision during head rotation, ensuring that the eyes maintain a steady gaze on an object even as the head moves. This reflex is crucial for visual stability, particularly during rapid head movements.

In contrast, the vestibule and cochlea serve different functions related to balance and hearing, respectively, while the tympanic membrane is involved in the auditory system, transmitting sound vibrations. Therefore, the semi-circular canals are the primary structure responsible for facilitating the angular VOR, allowing for effective coordination of head and eye movements.