ANP 1106 Lecture Notes - Lecture 19: Brainstem, Afferent Nerve Fiber, Auditory Cortex

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1106
• Professor: Jackie Carnegie

Document Summary

Dr. jackie carnegie & dr. w staines: special sense: balance and hearing. Sound: a pressure disturbance (alternating areas of high and low pressure) originating from a vibrating object. Composed of areas of rarefaction and compression. Loudness: subjective interpretation of sound intensity; pitch: perception of different frequencies (we hear from 20-20 000 hz cycle/s) Sound vibrations beat against the eardrum (tympanic membrane) External ear collects sound waves and passes them inwards; structures: Auricle (pinna): cartilage covered with skin; many animals have large auricles and can be oriented in different directions. External auditory canal (acoustic meatus): connect auricle to eardrum. Tympanic membrane (eardrum): skin and ct, where sound strikes and causes vibrations. Ear ossicles (in middle ear) the tympanic cavity contains three small bones: malleus, incus, and stapes. Transmits vibratory motion of the eardrum to the oval window. Dampened by the tensor tympani and stapedius muscles; example of cns control over sensory input: protects the auditory receptor cells; innervated by cranial nerves.