THE AUDITORY SYSTEM AND THE CHEMICAL SENSES D. C. MIKULECKY PROFESSOR OF PHYSIOLOGY AND FACULTY MENTORING PROGRAM
THE NATURE OF SOUND zCOMPRESSION AND RARIFICATION OF AIR zWAVES OF HIGH AND LOW PRESSURE zTRANSMIT MECHANICAL FORCES
CHARACTERISTICS OF A PRESSURE WAVE A T = WAVELENGTH A = AMPLITUDE f = 1/T FREQUENCY
ANATOMY OF THE EAR zOUTER EAR zMIDDLE EAR zINNER EAR
OUTER EAR zACTS TO FOCUS SOUND WAVES ON THE TYMPANIC MEMBRANE zSHAPED LIKE A SOUND CONE
OUTER EAR PINNA CANAL
MIDDLE EAR zTHREE BONES LINK TYMPANIC MEMBRANE TO OVAL WINDOW zVIBRATIONS TRANSMITTED MECHANICALLY
MIDDLE EAR TYMPANIC MEMBRANE OVAL WINDOW BONES OF MIDDLE EAR COCHLEAR FLUID SOUND WAVE IN EAR CANAL
INNER EAR zSITE OF TRANSDUCTION zVIBRATION OF COCHLEAR FLUID CAUSES BASILAR MEMBRANE TO VIBRATE zHAIR CELLS ARE DEFORMED zAUDITORY NERVE BECOMES EXCITED AS HAIR CELLS DEPOLARIZE
INNER EAR OVAL WINDOW COCHLEA
STRUCTURE OF THE COCHLEA SCALA VESTIBULI COCHLEAR DUCT SCALA TYPANI OVAL WINDOW ROUND WINDOW
STRUCTURE OF COCHLEAR DUCT BASILAR MEMBRANE TECTORIAL MEMBRANE ORGAN OF CORTI
TRANSDUCTION MECHANISM BASILAR MEMBRANE…..VIBRATES TECTORIAL MEMBRANE STATIONARY STEROCILIA AUDITORY NERVE HAIR CELLS
TRANSDUCTION MECHANISM TECTORIAL MEMBRANE STATIONARY BASILAR MEMBRANE…..VIBRATES STEROCILIA BEND AUDITORY NERVE HAIR CELLS
FREQUENCY DISCRIMINATION: LOCALIZATION OF DISPLACEMENT OF BASILAR MEMBRANE BASE APEX HIGH LOW MID
AUDITORY PATHWAYS COCHLEA VENTRAL COCHLEAR NUCLEUS MIDLINE DORSAL COCHLEAR NUCLEUS SUPERIOR OLIVE INFERIOR COLLICULUS INFERIOR COLLICULUS
AUDITORY PATHWAYS (CONT.) MIDLINE SUPERIOR OLIVE INFERIOR COLLICULUS INFERIOR COLLICULUS MEDIAL GENICULATE MEDIAL GENICULATE TEMPORAL CORTEX TEMPORAL CORTEX
CHARACTERISTICS OF A PRESSURE WAVE A T = WAVELENGTH A = AMPLITUDE f = 1/T FREQUENCY
PROPERTIES OF AUDITORY NERVE CELLS zEACH AUDITORY NERVE FIBER HAS AN OPTIMUM FREQUENCY zTHIS TONOTOPIC ORGANIZATION ARISES FROM POSITION IN THE COCHLEA zTONIC AND PHASIC NEURONS IN EACH AREA zSOME RESPOND TO CHANGE IN FREQUENCY zSOME RESPOND TO CHANGE IN AMPLITUDE
SOUND LOCALIZATION zINTERAURAL TIME DIFFERENCE zTIME DELAY BETWEEN TWO EARS zALSO INTENSITY DIFFERENCES
DISORDERS OF AUDITION zLOSS OF HAIR CELLS: FREQUENCY SPECIFIC zTINNITUS: RINGING zCONDUCTIVE:l DAMAGE TO MIDDLE EAR zCENTRAL: BRAIN TUMORS AND LESIONS
THE VESTIBULAR APPARATUS zSEMICIRCULAR CANALS: HAIR CELLS SENSE MOTION zTHREE COORDINATE PLANES: SUPERIOR, INFERIOR, AND HORIZONTAL zUTRICLE AND SACCULE DETECT LINEAR ACCELERATION IN HORIZONTAL AND VERTICLE PLANES
THE VESTIBULAR APPARATUS:UTRICLE & SACCULUS ONE CANAL IN EACH COORDINATE PLANE AMPULLA UTRICLE & SACCULUS
THE UTRICLE & SACCULUS HAIR CELLS NERVE CELLS OTOLITHIC MEMBRANE- GELATINOUS LAYER OTOCONIA (CALCIUM CARBONATE CRYSTALS)
THE UTRICLE & SACCULUS HAIR CELLS NERVE CELLS OTOLITHIC MEMBRANE- GELATINOUS LAYER OTOCONIA (CALCIUM CARBONATE CRYSTALS) HEAD MOVEMENT
THE VESTIBULAR APPARATUS: SEMICIRCULAR CANALS ONE CANAL IN EACH COORDINATE PLANE AMPULLA UTRICLE & SACCULUS
THE AMPULLA HAIR CELLS NERVE CELLS
THE AMPULLA HAIR CELLS BENT NERVE CELLS FIRE INERTIAL FLUID MOVEMENT MOVEMENT OF HEAD
VESTIBULAR INFLUENCE ON EYE MOVEMENTS zVESTIBULO-OCULAR REFLEX:COMPENSATES FOR HEAD MOVEMENT WHILE GAZING ON OBJECT zSACCADE:FAST MOVEMENT OF EYES IN DIRECTION OF HEAD MOTION zNYSTAGMUS:SLOW AND FAST MOVEMENTS OF EYES DURING ANGULAR ACCELERATION