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 Eye04/21 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
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
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 Ear16/21 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 Management20/21 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: 21/21Time to NCLEX BY: P.K. Williams, RN pkwilliams@DNI.edu