BIO271H1 Lecture Notes - Lecture 5: Choroid, Photon, Vestibular Duct
Document Summary
Lecture 5 (february 10, 2016): sensory physiology: photoreception. Waves goes from perilymph in vestibular duct, then to tympanic duct (low) (connected at helicotrema), then goes to cochlear duct where there is endolymph. When you increase vertical difference between sterecilia, potassium moves in because endolymph is so high in potassium: organ of corti, the sensory epithelium, hair cells sit strategically on the basilar membrane. You have 1 row of inner hair cells and 3 rows of outer hair cells. Outer outnumbers inner, but is not involved in transduction of signal back to cns, but rather the amplification. Stereociliary bundles attach to the tectorial membrane, so that if the basilar. Round window serves as a pressure valve. This is the activating of the prestin protein for contraction. Whichever region is vibrating those hair cells are vibrating: frequency signal converted to spatial signal. Sound waves go in two direction (through the basilar membrane and around the helicotrema)
