Overall structure of section of macula

Equilibrium (balance) exists in two forms:
Static equilibrium: maintenance of the body’s position relative to the force of gravity
Dynamic equilibrium: the maintenance of the body’s position in response to sudden movements.
Vestibular apparatus: The organs that maintain equilibrium. Includes saccule, utricle (both otolithic organs) and semicircular canals.
Otoliths are calcium carbonate crystals. The walls of the utricle and saccule contain a macula. The two maculae are receptors for static equilibrium.

The otolithic membrane sits on top of the macula. Movement of the head causes gravity to move it down over hair cells. The hair cells synapse with neurons in the vestibular branch of the vestibulocochlear (VIII) nerve.