Chapter 42
Sensory System
Sensation, Perception, and Cognition
• Sensation– Ability to receive and process stimuli through
sensory organs
• Perception– Ability to experience, recognize, organize, and
interpret sensory stimuli
• Cognition– Intellectual ability to think
(continued)
Anatomy and Physiology Review
• Central and peripheral nervous systems act to accomplish three purposes:1. Collect stimuli from receptors at end of
peripheral nerves
2. Transport stimuli to brain
3. Conduct responses to stimuli from brain to responsive motor centers in body
(continued)
Anatomy and Physiology Review
• Sensation and perception consists of afferent and efferent nerve pathways
• Cognition includes memory, affect, judgment, perception, and language
Assessment
• Focuses specifically on client’s ability to:– Hear– See– Taste– Smell– Touch
Disorientation
• Mentally confused state
• Person’s awareness of time, place, self, and/or situation impaired
Sensory Disorders
• Change in perception of sensory stimuli
• Can affect all five senses
• Sensory deprivation– State of reduced sensory input from internal
or external environment
• Sensory overload– State of excessive and sustained multi-
sensory stimulation
(continued)
Eye Anatomy
Eye Anatomy
Anterior Parts of the Eye
Impaired Vision
• Blindness– Central visual acuity 20/200 or less with
corrective lenses
• Partially sighted– Visual acuity between 20/70 and 20/200 in
better eye with glasses
• Many visual aids available
Refractive Errors
• Myopia– Nearsightedness
• Hyperopia– Farsightedness
• Astigmatism– Asymmetric focus of light rays on retina
(continued)
Refractive Errors
• Presbyopia– Inability of lens to change curvature in order
to focus
• Strabismus– Inability of eyes to focus in same direction
• Corrected with glasses or contacts
Normal Vision
Hyperopia Far Sighted
Myopia-Near Sighted
Foreign Bodies
• May cause excessive tearing and redness
• If particle not located and removed, instill sterile fluorescein drops or strips to visualize minute foreign bodies not readily visible with naked eye
Cataracts
• Disorder that causes lens or its capsule to lose transparency and/or become opaque
• As clouding develops, visual impairment occurs
• Treatment:– Surgical removal of lens
Cataracts
CataractsNormal
• Cataract
Glaucoma
• Disorder characterized by abnormally high pressure of fluid inside eyeball
• Treatment:– Drug therapy to reduce intraocular pressure
and iridectomy• Procedure to facilitate drainage of aqueous humor
Normal
Mild Glaucoma
Severe Glaucoma
Conjunctivitis (Pink Eye)• Inflammation of conjunctiva• Contagious• Causes:
– Bacterial, viral, or rickettsial organisms, allergens, and irritants
• Symptoms:– Burning, itching, discharge, swelling, pain, and
redness of eyes
• Treatment:– Warm compresses and antibiotic ointment
Conjunctivitis
Retinal Detachment
• Painless separation of retina from choroid
• May result from trauma or intraocular disorders
• Treatment:– Procedures that create inflammatory reaction
that results in retina reattaching to choroid and surgery
Retinal Detachment
Macular Degeneration
• Atrophy or deterioration of macula
• Central vision lost, but peripheral vision remains
• May be caused by aging, injury, infection, or inflammation of macula
• Help client maximize ability and prevent further damage if exudative
Macular Degeneration
Severe Macular Degeneration
Keratitis
• Inflammation of cornea
• Causes:– Infection, irritation, injury, and allergies
• Symptoms:– Severe eye pain, red and watering eye,
photophobia, reduced vision, and sometimes rash
• Treatment:– Optical anesthetics, mydriatics, and antibiotic
solutions
(continued)
Stye (Hordeolum)
• Pustular inflammation of eyelash follicle or sebaceous gland on lid margin
• Cause:– Staphylococcal organisms
• Symptoms:– Pain, redness, and swelling
• Treatment:– Warm compresses and topical antibiotics
(continued)
Chalazion
• Cyst of meibomian glands
• Symptoms:– Painless localized swelling that develops over
period of weeks
• Treatment:– Surgical excision
Chemical Burns
• Emergency treatment:– Immediate lavage of eye with tap water
• No attempt should be made to neutralize chemical– May cause further injury
• Both eyes should be patched for comfort
Impaired Hearing
• Conductive hearing loss– Inability of sound waves to reach inner ear
• Sensorineural hearing loss– Inner ear or cochlear portion of cranial nerve
VIII abnormal or diseased
• Once cause determined, client and doctor can decide on best therapy
Otitis Media
• Inflammation of middle ear
• Symptoms:– Ear pain, fever, redness of auricle and ear
canal, and sometimes enlarged lymph nodes
• Treatment:– Topical heat, analgesics, antihistamines,
decongestants, antibiotics, myringotomy, and tympanoplasty
Otitis Media
• What treatments would be used for this problem
Myringotomy
Otitis Externa
• Also known as swimmer’s ear
• Bacterial infection of external ear canal
• Symptoms:– Red and edematous canal skin, mild
conductive hearing loss, and discharge
Ménière’s Disease
• Also known as endolymphatic hydrops
• State of hearing loss characterized by tinnitus and vertigo
• Symptoms:– Classic triad of vertigo, tinnitus, and unilateral
fluctuating hearing loss
• Treatment:– Drugs, surgery, and dietary changes
(continued)
Otosclerosis
• Most common conductive hearing loss• Secondary to pathologic change of bones
in middle ear• Symptoms:
– Subtle changes in hearing and low-pitched tinnitus
• Treatment:– Do nothing, hearing aids, and surgical
stapedectomy
Acoustic Neuroma
• Slow-growing and usually benign tumor of vestibular portion of inner ear cranial nerve VIII
• Symptoms:– Dizziness, tinnitus, and hearing loss– May involve other cranial nerves with tumor growth
• Treatment:– Short-term pharmacological therapy and surgical
excision of tumor
(continued)
Mastoiditis
• Inflammation of mastoid
• Causes:– Chronic or recurrent bacterial otitis media
• Symptoms:– Earache, fever, headache, and malaise
• Treatment:– Antibiotics and surgical intervention
Taste
• Serves as protector
• Provides delightful sensations
• Can be altered secondary to neurological disorders or trauma
• Works very closely with sense of smell
Smell
• Serves as guardian from danger
• Disorders of olfactory sense often go unnoticed
• Body cannot regenerate olfactory cells
Touch
• Sensations pertaining to skin
• Tactile receptors located throughout integumentary system
• Clients with reduced or loss of tactile sensation risk injury when condition confines them to bed
Chapter 60
Infants with Special Needs:Birth to 12 Months
Otitis Media
• Inflammation of middle ear
• Symptoms:– Irritability, pulling at infected ear, diarrhea, vomiting,
fever, and hearing loss
• Prevention:– Proper positioning when feeding and smoke-free
environment
• Treatment:– Medications and myringotomy for recurrent
infections(continued)