The macula of utricle (macula acustica utriculi) is a small (2 by 3 mm) thickening lying horizontally on the floor of the utricle where the epithelium contains vestibular hair cells that allow a person to perceive changes in latitudinal acceleration as well as the effects of gravity; it receives the utricular filaments of the acoustic nerve.
The addition in weight and inertia is vital to the utricle's ability to detect linear acceleration, as described below, and to determine the orientation of the head.
Labyrinthine activity responsible for the nystagmus induced by off-vertical axis rotation arises in the otolith organs and couples to the oculomotor system through the velocity storage mechanism.
The utricle contains mechanoreceptors called hair cells that distinguish between degrees of tilting of the head, thanks to their apical stereocilia set-up.
Depending on whether the tilt is in the direction of the kinocilium or not, the resulting hair cell polarisation is excitatory (depolarising) or inhibitory (hyperpolarisation), respectively.
The otolithic membrane of the macula utriculi briefly lags behind the rest of the tissues, bends the stereocilia backward, and stimulates the cells.
The hair cells convert this pattern of stimulation to nerve signals, and the brain is thus advised of changes in your linear velocity.