Which part of the vestibular complex is responsible for detecting rotational acceleration of the head?

The correct response highlights that all components of the vestibular complex play essential roles in maintaining balance and spatial orientation, but specifically, the ampullae are crucial for detecting rotational acceleration of the head. The vestibular complex includes the utricle, saccule, and ampullae, each contributing to different aspects of vestibular function.

The utricle and saccule, which are the otolithic organs, primarily detect linear acceleration and the position of the head relative to gravity. These organs contain otoliths (tiny calcium carbonate crystals) that shift in response to gravity and linear movements, stimulating hair cells that send signals regarding head position and motion.

On the other hand, the ampullae are located within the semicircular canals and specifically encapsulate structures sensitive to rotational movements. Each ampulla contains a structure called the crista, which has hair cells embedded in a gel-like substance known as the cupula. When the head rotates, the fluid (endolymph) within the semicircular canals lags behind due to inertia, causing the cupula to bend and stimulate the hair cells. This bending creates nerve impulses that inform the brain about the direction and speed of the head's rotation.

Thus, while all parts of the vestibular system are