Chapter 42 Sensory System

Sensation, Perception, and Cognition 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: Collect stimuli from receptors at end of peripheral nerves Transport stimuli to brain 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 Partially sighted Many visual aids available 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 Hyperopia Astigmatism Nearsightedness Farsightedness Astigmatism Asymmetric focus of light rays on retina (continued)

Refractive Errors Presbyopia Strabismus Inability of lens to change curvature in order to focus Strabismus Inability of eyes to focus in same direction Corrected with glasses or contacts This slide added. 15

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

Cataracts Normal 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: Symptoms: Treatment: 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: Treatment: 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 Sensorineural 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

Ear Website

Otitis Media Inflammation of middle ear Symptoms: Treatment: 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: Symptoms: Treatment: 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

Infants with Special Needs: Birth to 12 Months Chapter 60 Infants with Special Needs: Birth to 12 Months 56

Otitis Media Inflammation of middle ear Symptoms: Prevention: 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)