Overall, the vestibular sense helps us to maintain balance, and it provides information about head position and movement. There are three main components, which are the semicircular canals, the utricle, and the saccule. The semicircular canals are responsive to movement of the head in three directions. This is achieved via a gelatinous mass called the cupula, which has hair cells that protrude into it. When the head moves in one direction during acceleration, the cupula also moves. However, the fluid does not move, causing the cupula to bend in the opposite direction of the head. This causes the hair cells that protrude into the cupula to bend, depolarizing them and increasing rate of neural activity. Movement of the head the other direction has an opposite effect where the hair cells bend in the opposite direction and causes hyperpolarization - a decrease in the neural activity.
The utricle and saccule are used to monitor the position of the head in relation to gravity. The hair cells are covered with a gelatinous mass that contains otoliths. When the head tilts, gravity shifts the mass, and the hair cells are depolarized or hyperpolarized. These two components are able to detect the tilting of the head in any direction due to the position of the hair cells on each - on the utricle, the hair cells are arranged horizontally, while on the saccule they are arranged vertically.