Unformatted text preview: Lecture 10 SmartSite: Lecture 10 Notes Review Sensory Systems The Ear Announcements: None Reading (Recommended): Relevant por<ons of Chapter 6 Auditory system Ves<bular system 1 REV: Sensory Integra<on 1. Modality or type of sensory informa<on 2. Receptor type 3. AP firing rate of afferent propor<onal to s<mulus intensity 4. Rate of receptor adapta<on 5. Number of afferents firing 6. Receptor density / Receptor field size 7. Lateral inhibi<on 8. Labeled line coding 2 REV: Sound Wave Transmission Tympanic membrane vibrates when struck by sound waves Middle ear transfers vibra<ons through ossicles to oval window Pressure waves in cochlear fluid set basilar membrane in mo<on Recep<ve hair cells are bent as basilar membrane is deflected up and down Mechanical deforma<on of specific hair cells is transduced into afferent neural signals APs are transmiXed to auditory cortex in temporal lobe of brain for sound percep<on Fig. 6-36a, pg. 219 3 REV: Transmission of Sound Waves Fig. 6-36bc, pg. 219 4 Sound Transduc<on hXp://www.rockefeller.edu/labheads/hudspeth/graphicalSimula<ons.php 5 Cochlea Fig. 6-35ab, pg. 218 6 Auditory Receptors Fig. 6-357 pg. 220 7 Hair Cells Fig. 6-40, pg. 223; Fig 6-38c, pg 221 8 Sound Transduc<on Fig. 6-39, pg. 222 9 Ear - Ves<bular Fig. 6-32, pg. 215 10 Ves<bular - Equilibrium Ves<bular apparatus and receptors In inner ear Consists of 2 classes of receptors Semicircular canals (3 orthogonally-oriented canals per side) Detect rota<onal accelera<on or decelera<on in any direc<on Otolith organs (2 Macular receptors at right angles per side: utricle and saccule) Detect linear accelera<on Detect changes in rate of linear movement in any direc<on Provide informa<on important for determining head posi<on in rela<on to gravity 11 Equilibrium Neural signals generated in response to mechanical deforma<on of hair cells by specific movement of fluid and related structures Ves<bular input goes to ves<bular nuclei in brain stem and to cerebellum for use in maintaining balance and posture, controlling eye movement, perceiving mo<on and orienta<on 12 13 Ves<bule Fig. 6-41a, pg. 225 14 Semicircular Canals Hair cell bundles are aligned in mirrored orienta<on Rota<on depolarizes one set of hair cells and hyperpolarizes the hair cells in the opposite semicircular canal Fig. 6-41c, pg. 225 15 Semicircular Canals Fig. 6-41c, pg. 225 16 Hair Cell Receptors The response is similar to that in auditory hair cells Stereocilia bending toward the kinocilium: Depolariza<on Stereocilia bending away from the kinocilium: Hyperpolariza<on 17 Fig. 6-41d, pg. 225 Otolith Organs (macular receptors) Fig. 6-42a, pg. 226 18 Linear Accelera<on Fig. 6-40bc, pg. 221 19 Ves<bular Input-Output Rela<ons Fig. 6-43, pg. 227 20 ...
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- Spring '08
- temporal lobe, pg, ovalwindow, Haircell