The parts of the ears involved in balance are the semicircular canals . Above, the semicircular canals are colored purple ( Figure above ). The canals contain liquid and are like the bottle of water pictured below ( Figure below ). When the bottle tips, the water surface moves up and down the sides of the bottle. When the body tips, the liquid in the semicircular canals moves up and down the sides of the canals. Tiny hair cells line the semicircular canals. Movement of the liquid inside the canals causes the hair cells to send nerve impulses. The nerve impulses travel to the cerebellum in the brain along the vestibular nerve. In response, the cerebellum sends commands to muscles to contract or relax so that the body stays balanced.
Terri and Brian have appointments with an ENT to discuss some symptoms they have been having. During the exam, Terri's doctor tells her that the structures in her ear appear to be fine. Brian's doctor tells him that it appears as though he has suffered some damage to his semicircular canals.
Who is less likely to have problems staying balanced, Terri or Brian?