PSL440Y1 Study Guide - Midterm Guide: Posterior Parietal Cortex, Premotor Cortex, Hemispatial Neglect
Document Summary
Cochlear areas of maximum vulnerability: stria vascularis. Presbycusis loss of hearing that gradually occurs in most individuals as they grow older: haircells. Presbycusis: strial function reduces electrical driving force for haircell activation. Most cochlear damage likely occurs first at the cochlear afferent nerve terminal. Sound vibrations from an object cause vibrations in air molecules, which in turn, vibrate your ear drum. The movement of the eardrum causes the bones of your middle ear (the ossicles) to vibrate. These vibrations then pass in to the cochlea, the organ of hearing. Within the cochlea, the hair cells on the sensory epithelium of the organ of corti bend and cause movement of the basilar membrane. The membrane undulates in different sized waves according to the frequency of the sound. Hair cells are then able to convert this movement (mechanical energy) into electrical signals (graded receptor potentials) which travel along auditory nerves to hearing centres in the brain.
