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GENERAL PRINCIPLES OF SENSORY TRANSDUCTION. Donald C. Mikulecky Department of Physiology and Faculty Mentoring Program. ORGANIZATION OF THE NERVOUS SYSTEM. BRAIN SPINAL CORD. CENTRAL NERVOUS SYSTEM (CNS). AFFERENT NERVES. EFFERENT NERVES. PERIPHERAL NERVOUS SYSTEM. EXTERO- - PowerPoint PPT Presentation
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04/22/23
GENERAL PRINCIPLES OF SENSORY TRANSDUCTION
Donald C. MikuleckyDepartment of PhysiologyandFaculty Mentoring Program
ORGANIZATION OF THE NERVOUS SYSTEM
BRAINSPINAL CORD
CENTRALNERVOUSSYSTEM (CNS)
PERIPHERALNERVOUS SYSTEM
AFFERENT
NERVES
EFFERENT
NERVES
EXTERO-RECEPTORS
INTERO-RECEPTORS
SOMATIC AUTONOMIC
EFFECTORORGANS
SKELETALMUSCLES
SMOOTH AND CARDIAC MUSCLES AND GLANDS
GENERAL PRINCIPLES OF SENSORY SYSTEMSSENSORY TRANSDUCTION: SPECIFIC
MODALITIES WITH ADEQUATE STIMULUSA SENSORY UNIT: SENSORY NEURON
AND ALL THAT IT INNERVATESEXTERORECEPTIVE AND
PROPRIORECEPTIVEPATHWAYSINTEGRATION
NEOCORTEX
THALAMUS
LIMBICCORTEX
BRAINSTEM
SPINALCORD
NOSE
EYE
TONGUE
EAR
SKIN
SMELL
VISION
TASTE
AUDITION
SOMATIC
SENSORY INFORMATION TRAVELSTO THE BRAIN VIA SPECIALIZED PATHWAYS
SENSORY MODALITIES AND RECEPTOR CELLS
MODE RECEPTOR ORGANVISION RODS,CONES EYEHEARING HAIR CELLS EARMOTION HAIR CELLS VESTIBULAR
APPARATUS
SMELL OLIFACTORYNEURONS
OLIFACTORYMUCOUS MEMB.
TASTE TASTE RECEPTORCELLS TASTE BUDS
TOUCH-PRESSURE
NERVE ENDINGS SKIN
SENSORY MODALITIES AND RECEPTOR CELLS
MODE RECEPTOR ORGANWARMTH NERVE ENDINGS SKINCOLD NERVE ENDINGS SKINPAIN NAKEDNERVE
ENDINGSSKIN
JOINTMOVEMENT &POSITION
NERVE ENDINGS VARIOUS
MUSCLELENGTH
NERVE ENDINGS MUSCLESPINDLE
MUSCLETENSION
NERVE ENDINGS GOLGI TENDONORGAN
TYPES OF ENERGY TRANSDUCED
RECEPTOR TYPE ENERGY HANDLEDMECHANORECEPTORSTOUCH,PRESSURE,PAIN
MECHANICAL: PRESSURE ORPHYSICAL DISPLACEMENT
THERMORECEPTORS HEAT OR COLDCHEMORECEPTORS:TASTE AND SMELL
CHEMICAL
PHOTORECEPTORS VISIBLE LIGHTNOCIOCEPTORS:PAIN
TISSUE DAMAGE
ADEQUATE STIMULUSA SPECIFIC STIMULUS UNIQUE TO A
SENSORY RECEPTOR
FOR EXAMPLE, PHOTORECEPTORS IN THE EYE RESPOND ONLY TO ELECTROMAGNETIC RADIATION
GRADED VS ALL OR NONE A RECEPTOR’S RESPONSE TO A
STIMULUS IS GRADED
IF THRESHOLD IS EXCEEDED, THE ACTION POTENTIAL RESULTING IS ALL OR NONE
EXAMPLE: THE PACINIAN CORPUSCLEPRESSURE RECEPTORPRESSURE DISTORTS THE CAPSULE,
STRETCHING THE CELL MEMBRANESODIUM CHANNELS OPEN,
DEPOLARIZING THE MEMBRANEIF BEYOND THRESHOLD, ACTION
POTENTIAL RESULTS
SENSORY TRANSDUCTION
ADEQUATE STIMULUS
MEMBRANECONDUCTANCE
CHANGE
GENERATORPOTENTIAL
ACTIONPOTENTIAL
HOW IS THE INTENSITY OF THE STIMULUS ENCODED?
FREQUENCY CODING
POPULATION CODING
FREQUENCY CODINGLIGHT PRESSURE
LOW FREQUENCY
MORE PRESSURE
HIGHERFREQUENCY
POPULATION CODING
LIGHT PRESSURE
MORE PRESSURE
NEOCORTEX
THALAMUS
LIMBICCORTEX
BRAINSTEM
SPINALCORD
NOSE
EYE
TONGUE
EAR
SKIN
SMELL
VISION
TASTE
AUDITION
SOMATIC
THE LABELED LINE CODE OF STIMULUS QUALITY
LOCALIZATION, DISTRIBUTION, AND ACUITY
CODING OF LOCATION DEPENDS ON RECEPTOR LOCATION
AREA COVERED BY RECEPTORS IN A SENSORY UNIT IS A RECEPTIVE FIELD
ACUITY DEPENDS ON THE DENSITY OF RECEPTORS