The ear is the organ in control of the sense of balance. Inside the inner ear is the vestibular system, which is essential for our sense of balance and postural equilibrium. It also coordinates the position of our head with the movement of our eyes. It's made of three semicircular canals, with a space at the end, filled with fluid and small hair cells. Whenever we turn our heads, the inner ear turns along with it, moving the fluid inside and bending the sensory hairs. These hair cells then send information to the brain.

Source: National Library of Medicine