How do the utricle and otoliths detect linear acceleration and head tilt?

The utricle and saccule, collectively known as the otolith organs, function as gravity receptors that detect linear acceleration and head tilt through a specialized biological process involving shearing forces.123

Within each organ, a patch of sensory cells called a macula contains hair cells topped with bundles of stereocilia and a single kinocilium. These hair cells are covered by a gelatinous otolithic membrane embedded with dense calcium carbonate crystals called otoliths (or otoconia).2314

When the head tilts or undergoes linear acceleration, the dense otoliths create inertia, causing the membrane to shift relative to the underlying hair cells. This movement creates a shearing force that deflects the hair bundles. This deflection alters the rate of nerve impulses sent to the brainstem via the vestibulocochlear nerve, providing the brain with information about the head's position and movement. Because the utricular maculae are oriented horizontally, they are particularly sensitive to side-to-side tilts and horizontal acceleration.15243