Physiology 3120 Lecture Notes - Lecture 7: Tonotopy, Brainstem, Visual Cortex

• School: Western University
• Department: Physiology
• Course: Physiology 3120
• Professor: Tom Stavraky

Document Summary

Reason auditory system is much faster than visual system is because auditory system uses hair cells whereas in visual system it is done using second messenger cascades, etc. Image shows that there are many cilia stacked up together to form one hair cell. It is easy for a loud sound to whip these hair cells around and to shear them off their base cannot grow back hair cells so once you lose them, they are gone forever. This frequency range is for young people which narrows down with age. People older than 60 cannot hear beyond 10,000hz. Damage to hair cells when listen to more than 100 decibels for more than 5 minutes very delicate system. Spatial resolution so can pinpoint from where exactly sound is coming. Hair cells transduce energy in the envt into ap. Inner ear is where the hair cells are located in fluid-filled membranous tubules. Top shows what the cochlea looks like when uncurled.