Deep inside the head is the inner ear, which contains 3 small, fluid-filled structures called the semicircular canals (ducts). Each duct has a swelling at the end called the ampulla. Within the ampulla are tiny "balance" receptors called crista.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.