Statoreceptoren

Statoreceptoren, or statoreceptors, are mechanosensory cells of the vestibular system that detect static head position and linear acceleration relative to gravity. They reside in the otolith organs, the utricle and the saccule, each containing a sensory epithelium called a macula. The maculae sit within an otolithic membrane bearing tiny calcium carbonate crystals known as otoliths (otoconia), which add mass and enhance sensitivity to tilt and linear movement.

The sensory cells are hair cells with stereocilia and a single kinocilium. Deflection of the hair bundles toward the kinocilium increases the firing rate of the afferent nerve fibers, while deflection away decreases it. When the head tilts or experiences linear acceleration, gravity and inertia cause the otolithic membrane to shear over the macula, bending the hair cells and generating altered receptor potentials. The utricle macula is oriented horizontally and primarily detects horizontal accelerations, whereas the saccule macula is vertically oriented and primarily detects vertical accelerations.

Afferent signals from the maculae travel via the vestibular portion of cranial nerve VIII to the vestibular nuclei in the brainstem and to the cerebellum. These inputs contribute to balance and posture control and to the vestibulo-ocular reflex, which stabilizes gaze during head movements.

Clinical notes: Dysfunction of statoreceptors can contribute to imbalance or vertigo and may accompany broader vestibular disorders. Otolith-related symptoms are generally evaluated alongside semicircular canal function, which is detected by the cristae ampullares in the semicircular canals.