Timby/Smith: Introductory Medical-Surgical Nursing, 10/e 01/21 Pg 595 S-54 Chapter 41: Introduction to the Sensory System By: P.K. Williams, RN

23 Words to Know*** 02/21 Pg 595 Accommodation Audiometry Caloric stimulation test Central vision Conductive hearing loss Conjunctivitis Decibels Elelctronystagmography Near point Nystagmus Ophthalmoscopy Otoscope Proptosis Ptosis Refraction Rinne Test Romberg Test Sensorineural hearing loss Tonometry Tuning fork Visual acuity Visual field examination Weber test

Unit 10 Chpt 41 Learning Objectives 03/21 Pg 595 On completion of this chapter, you will be able to: 01. Describe the anatomy and physiology of the eyes. 02. Discuss tests that are used for visual screening. 03. Identify questions to ask during an eye assessment. 04. Describe diagnostic studies for eye function 05. Explain the anatomy and physiology of the ears. 06. Describe methods for assessing the ear and hearing acuity. 07. Describe specific diagnostic tests for ear function.

Anatomy, Physiology of the Eye 04/21 Pg 595 Extraocular Structures*** Eyelids, eyelashes, tears: Protect the eye Canthus: Where eyelids meet; Usually horizontal; Down syndrome; Epicanthal fold Blinking: Clears dust, particles from eye surface Eyelids: Adjust amount of light entering eyes; Distribute tears; Multiple glands; Conjunctiva; Caruncle; Lacrimal apparatus Tears: Water, Sodium chloride, lysozyme [antibacteria enyzemel]***

Anatomy, Physiology of the Eye*** 04/19 Pg 595 Figure 41-1 External structures of the eye and position of the lacrimal structures

Intraocular Structures*** 06/00 Pg 596 Three Layers Sclera (White of the eye) Protects structures within the eye Connects to cornea, anterior chamber, pupil Uvea (Vascular coat of the eye) Choroid; Iris; Pupil; Aqueous humor; Vitrous humor Retina Rods and cones; Macula

Figure 41-2 Three-dimensional cross-section of the eye The Eye*** Fig:41-2 06/21 Pg 597 Figure 41-2 Three-dimensional cross-section of the eye

Visual Function*** Fig: 41-3 08/21 Pg 597/596 Light  Nerve signals: Interpreted in cerebral cortex Refraction;RETINA = Rods [dim light dark colors], Cones [ bright light colors]  Optic nerve; Accommodation Near point; Cataract: Opaque lens, blurred, cloudy images Figure 41-3 A normal opthalmoscopic picture. The fundus or back of the eye as seen through an ophthamoscope. The optic disc, with its radiating vasculature, is easily distinguished from the macula lutea.

Nursing Assessment*** 09/21 Pg 597 Client History Allergy; Vision changes; Discomfort; Corrective lenses Eye medications; Eye trauma, disease, surgery Family history of eye disease Physical Assessment Symmetry [13% Pop USA= unequal pupils] Inflammation; Exudate = [drainage] Pupil constriction

Eye Assessment*** 10/19 Pg 597 Visual Screening Tests Snellen eye chart: Visual acuity Jaeger chart; Rosenbaum Pocket Vision Screener: Near vision Ishihara polychromatic plates: Color vision Extraocular Muscle Function Corneal light reflex test: Eye alignment Cover-uncover test: Extraocular muscle function Positions test: Eye muscle strength, cranial nerve function

Not in Text 11/20

Snelling Eye Chart*** Not in Text 11/21

Diagnostic Studies *** 13/21 Pg 600 Ophthalmoscopy: Examination of fundus*** Retinoscopy: Focusing power of each eye*** Tonometry: Intraocular pressure*** Normal IOP: 10 to 21 mm Hg*** Visual Field Examination Peripheral vision; Gaps Visual field change associations: Glaucoma; Stroke; Brain tumor; Retinal detachment Color Vision Testing: Color differentiation ability

Diagnostic Studies *** 14/21 Pg 600 Amsler Grid: Macular problems Slit-lamp Examination: Magnifies eye surface Identifies: Corneal abrasions; Iritis; Cataracts; Conjunctivitis Retinal Angiography: Vascular changes, blood flow Ultrasonography: Used when posterior of eye difficult to visualize Retinal Imaging: High-resolution; Pupil dilation unnecessary

Nursing Management 15/21 Pg 601 Client Education Maintenance, preservation of eye function Obtain an Accurate Baseline Client Assessment for Further Action

Anatomy and Physiology of the Ear 16/21 Pg 601 Subdivisions of the Ear: Outer; Middle; Inner*** Outer ear (Auricle)*** Pinna; External acoustic meatus; Tympanic membrane Middle ear*** Eustachian tubes; Malleus; Incus; Stapes Inner ear (Labyrinth)*** Cochlea (hearing); Semicircular canals (balance); Vestibulocochlear nerve (Cranial nerve VIII; Organ of Corti

Subdivisions of the Ear *** 17/21 Pg 602 Figure 41-8 Diagram of the ear, showing the external, middle, and internal subdivisions.

Ear Assessment*** 18/21 Pg 602 Basic Auditory Acuity Tests Whisper test: Gross auditory acuity Otoscopic Examination: External acoustic canal, tympanic membrane inspection Tuning Fork Tests Conductive or sensorineural hearing loss Rinne test; Weber test Romberg Test: Ability to sustain balance

Diagnostic Studies 19/21 Pg 600 Audiometry: Precise measurement of hearing acuity; Measured in decibels (dB) Lowest perceptible sound perceived: 20 dB Painful sound level: 120 dB Caloric Stimulation Test  Nystagmus Measures vestibular reflexes of inner ear Electronystagmography: Vestibular function Used in conjunction with caloric stimulation test Measures duration, velocity of eye movements during nystagmus

Nursing Management 20/21 Pg 605 Client Assessment: Ear structure; Hearing function*** Screening in healthcare settings Baseline for further testing, referral Client education: Maintenance of hearing function and testing

End of Presentation: 21/21 Time to NCLEX BY: P.K. Williams, RN pkwilliams@DNI.edu