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Chapter 9: The Sensory System

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Learning OutcomesIdentify parts and their function of the sensory

systemDefine related combining word formsRecall related diagnoses, tests, and clinical

procedures in treating disordersDefine related pathologies of the sensory systemDefine related surgical termsRecognize related pharmacological agents used

in treating disorders of the sensory system

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Function/StructureSensory System includes organs involved in

perceiving and receiving stimuliAristole - Identified the five sensesNeurons = specialized nerve endingsDendrites = respond to only one sensationElectrochemical signals

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Sensory ReceptorsReceptor cells able to receive stimuliReceive only certain stimuliSend impulses to afferent (conductive) nerves

to interpret stimuli

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The Sensory System

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Combining Formsaudi(o), audit(o) hearingaur(o), auricul(o) hearingblephar(o) eyelidcerumin(o) waxcochle(o) cochleaconjunctiv(o) conjunctivacor(o), core(o) pupil

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Combining Formscorne(o) corneacycl(o) ciliary bodyir(o), irid(o) iriskerat(o) cornealacrim(o) tearsmastoid(o) mastoid process

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Combining Formsmyring(o) eardrum,

middle earnas(o) noseocul(o), eyeophthalm(o), eyeopt(o), optic(o) eyeossicul(o) ossicle

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Combining Formsphac(o), phak(o) lenspupill(o) pupilretin(o) retinascler(o) white of the eyescot(o) darknesstympan(o) eardrum, middle earuve(o) uvea 

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Sight- The EyesThe eyes detect light and stimulate sensory

receptorsContain about 70 percent of all the receptors

in the human body

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Details of the Eye

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Hearing and EquilibriumEar - organ for hearing/balanceMajor divisions of the ear:ExternalMiddleInner

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Details of an Ear

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Decibel Levels40dB = A whisper60dB = Regular speech80dB = High noise130dB = Extremely Loud140dB = Jet engine

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Touch, Pain, TemperatureThe SkinIntensities of touchLight touch - top layer of skin Harder pressure - middle and bottom layerSense of touch, pressure, pain, temperaturesPain receptor

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Smell and TasteOlfactory nerves = ability to perceive a scentTaste buds = tongue surface Loss of sense of smell and taste major impact

on every day life

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Diagnostic, Procedural, and Lab TestAssist in diagnosis and treatment of the

sensory conditionsQuestions/examination of structuresLoss of a sense can be seriousPartially or totally restoredAdapt to the loss

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Pathological Terms Lost/damaged sensesLead to other related illnessesAge-related disordersWear and tear on sensory organs

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Astigmatism/Correction

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Hyperopia/Myopia

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Ear DisordersSense of hearing can be diminished or lost in

a number of situationsHearing loss can impact nearly every aspect

of an individual’s life

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Surgical TermsSurgery may be performed on sensory systemDeficits may be restored, removal of

cancerous tumors, and cosmetic changes

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Pharmacological TermsMay be used to treat conditions or to assist in

identifying conditionsMedications usage for short or extended

timeframe

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Chapter ReviewIdentify parts and their function of the sensory

systemDefine related combining word formsRecall related diagnoses, tests, and clinical

procedures in treating disordersDefine related pathologies of the sensory systemDefine related surgical termsRecognize related pharmacological agents used

in treating disorders of the sensory system