SPA 4032 Lecture Notes - Lecture 3: Homeostasis, Critical Role, Otolith
16 Sep 2016
School
Department
Course
Professor
Document Summary
Of hearing loss if we didn"t have a middle ear. Two subsystems and 4 subdivisions of the ear: outter ear, middle ear, inner ear, auditory nerve. How we hear: aucoustical (outer ear) mechanical (middle ear) hydraulic (oval window) . Chemical (cochlear) electrical (cochlea) brain (neural-auditory nerve) Functions: ow separates me from ie, point of entry = vestibule (access to many areas w/in ie) Utricle and saccule (endolymph: vestibular: body position/movement/balance = bioelectrical code (control- cerebellum) Three semi circular canals (anterior, posterior, lateral) (endolymph) Scc returns to utricle via ampullae, which house crista = responsible for equilibrium. It plays a role in hearing tests that involve bone conduction stimulation. Inner hair cells: single row with approx. 3000 ihcs per cochlea: responsible for sensory transduction, receive primarily afferent innervation (ascending to brain, stereocilia are not imbedded in the tectorial membrane, shaped like a flask.
