Chapter 9:
The Sensory System
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Learning Outcomes
 Identify parts and their function of the sensory system
 Define related combining word forms
 Recall related diagnoses, tests, and clinical procedures
in treating disorders
 Define related pathologies of the sensory system
 Define related surgical terms
 Recognize related pharmacological agents used in
treating disorders of the sensory system
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Function/Structure
 Sensory System includes organs involved in perceiving
and receiving stimuli
 Aristole - Identified the five senses
 Neurons = specialized nerve endings
 Dendrites = respond to only one sensation
 Electrochemical signals
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Sensory Receptors
 Receptor cells able to receive stimuli
 Receive only certain stimuli
 Send impulses to afferent (conductive) nerves to
interpret stimuli
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The Sensory System
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Combining Forms
 audi(o), audit(o)
 aur(o), auricul(o)
 blephar(o)
 cerumin(o)
 cochle(o)
 conjunctiv(o)
 cor(o), core(o)
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hearing
hearing
eyelid
wax
cochlea
conjunctiva
pupil
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Combining Forms
 corne(o)
 cycl(o)
 ir(o), irid(o)
 kerat(o)
 lacrim(o)
 mastoid(o)
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cornea
ciliary body
iris
cornea
tears
mastoid process
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Combining Forms
 myring(o)
 nas(o)
 ocul(o),
 ophthalm(o),
 opt(o), optic(o)
 ossicul(o)
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eardrum,
middle ear
nose
eye
eye
eye
ossicle
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Combining Forms
 phac(o), phak(o)
 pupill(o)
 retin(o)
 scler(o)
 scot(o)
 tympan(o)
 uve(o)
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lens
pupil
retina
white of the eye
darkness
eardrum, middle ear
uvea
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Sight- The Eyes
 The eyes detect light and stimulate sensory receptors
 Contain 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 Equilibrium
 Ear - organ for hearing/balance
 Major divisions of the ear:
 External
 Middle
 Inner
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Details of an Ear
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Decibel Levels
 40dB
 60dB
 80dB
 130dB
 140dB
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= A whisper
= Regular speech
= High noise
= Extremely Loud
= Jet engine
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Touch, Pain, Temperature
 The Skin
 Intensities of touch
 Light touch - top layer of skin
 Harder pressure - middle and bottom layer
 Sense of touch, pressure, pain, temperatures
 Pain receptor
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Smell and Taste
 Olfactory nerves = ability to perceive a scent
 Taste buds = tongue surface
 Loss of sense of smell and taste major impact on every
day life
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Diagnostic, Procedural,
and Lab Test
 Assist in diagnosis and treatment of the sensory
conditions
 Questions/examination of structures
 Loss of a sense can be serious
 Partially or totally restored
 Adapt to the loss
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Pathological Terms
 Lost/damaged senses
 Lead to other related illnesses
 Age-related disorders
 Wear and tear on sensory organs
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Astigmatism/Correction
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Hyperopia/Myopia
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Ear Disorders
 Sense of hearing can be diminished or lost in a
number of situations
 Hearing loss can impact nearly every aspect of an
individual’s life
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Surgical Terms
 Surgery may be performed on sensory system
 Deficits may be restored, removal of cancerous
tumors, and cosmetic changes
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Pharmacological Terms
 May be used to treat conditions or to assist in
identifying conditions
 Medications usage for short or extended timeframe
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9-24
Chapter Review
 Identify parts and their function of the sensory system
 Define related combining word forms
 Recall related diagnoses, tests, and clinical procedures
in treating disorders
 Define related pathologies of the sensory system
 Define related surgical terms
 Recognize related pharmacological agents used in
treating disorders of the sensory system
McGraw-Hill
© 2013 by The McGraw-Hill Companies, Inc. All rights reserved.