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Transcript
SPECIAL SENSES: The Eyes and Ears Learning Objectives 1. 2. 3. 4. Describe the functions and structures of the eyes and adnexa. Recognize, define, spell, and pronounce terms related to the pathology and diagnostic and treatment procedures of eye disorders. Describe the functions and structures of the ears Recognize, define, spell, and pronounce terms related to the pathology and diagnostic and treatment procedures of ear disorders. Key Word Parts Blephar/o -cusis Dacrocyst/o Irid/o Kerat/o -metry Opthalm/o -opia Ot/o Presby/o Pseud/o Retin/o Scler/o Trop/o Tympan/o Major structures and their functions Eyes (op/ti, opt/o, optic/o, opthalm/o) receptor organs for the sense of sight. Receive images and transmit them to the brain. Adnexa of the eye – accessory structures that provide external protection and movement for the eyes. Lacrimal apparatus (lacrim/o, dacry/o) produces, stores, and removes tears. Major structures and their functions Lens (phac/o) focuses rays of light on the retina. Iris (ir/i, ir/o, irid/o, irit/o) controls the amount of light entering the eye. Retina (retin/o) converts light images into electrical impulses and transmit them to the brain. Terminology pertaining to the eyes Optic Ocular Extraocular – outside the eyeball Intraocular – within the eyeball Adnexa of the Eyes Also known as adnexa oculi • Orbit (eye socket) • Eye muscles • Eyelids • canthus • Eyelashes • Conjunctiva • Lacrimal apparatus Adnexa of the Eyes The Eyeball Also known as the globe Made up of three layers: • Sclera known as the white of the eye • Cornea is the transparent anterior portion of the sclera. • Choroid • Retina The Eyeball The Iris, Pupil, and Lens Iris – pigmented (colored) muscular layer that surrounds the pupil. Pupil – black circular opening in the center of the iris that permits light to enter the eye. Lens – clear, flexible, and curved structure that focuses images of the retina. The Uveal Tract Vascular layer of the eye The Eye The Retina Sensitive inner nerve layer of the eye. Rods – light sensitive cells, black and white receptors Cones – color receptors Macula lutea is the area of sharpest central vision. Segments of the Eye Anterior chamber • Aqueous fluid Posterior chamber • Vitreous humor • Soft, clear, jelly-like mass aids the eye in maintaining its shape. Normal Action of the Eyes Accommodation • Seeing objects at various distance • Pupil dilate/constrict Convergence – simultaneous inward movement of both eyes to maintain single binocular vision. Emmetropia Refraction Visual Acuity Normal vision as 20/20 Snellen Chart • Indicates the distance from the chart which is standardized at 20 feet. (first number) • Indicates the deviation from the norm based on the ability to read lines of letters on the chart. (second number) Pathology of the Eyes The Eyelids • Blepharoptosis • Ectopion • Entropion • Hordeolum • Chalazion Pathology of the eyelids Conjunctivitis Adnexa Pathology • Dacryocystitis • Conjunctivitis • Xerophthalmia – also known as dye eye, drying of the eye surfaces characterized by the loss of luster of the conjunctiva and cornea Sclera, Cornea, and Iris Scleritis Keratitis Corneal abrasion Corneal ulcer Iritis Synechia Scleritis, Iritis, synechia 100 50 0 1st Qtr 3rd Qtr East West North The Eye Anisocoria Cataract Choked disk Floaters Nystagmus Retinal detachment Uveitis Cataract Glaucoma It is an eye disease where the fluid pressure within the eyeball is too high and damages the optic nerve, which carries visual impulses from the eye to the brain. This pressure build-up occurs because of an imbalance between the production and drainage of fluid within the eyeball. Glaucoma Macular Degeneration Age-related macular degeneration (AMD) is a major public health problem. It is the most common cause of visual loss in developed countries in individuals over the age of 60. It is estimated that by the year 2000, more than 2 million people in the United States will be afflicted with this serious sight-threatening disorder. Macular Degeneration The Eye Functional Defects Diplopia Hemianopia – blindness in one half of the visual field Monochromatism Nyctalopia – night blindness Presbyopia Strabismus - squint Esotropia –cross eye Exotropia – wall eye The Eye Refractive Disorders Ametropia – out of proportion (finite distance) Astigmatism –unequal curvature of the lens Hyperopia - farsightedness Myopia - nearsightedness Blindness Amblyopia - dimness Legal Blindness – 20/200 Scotoma - blindspot Esotropia & Exostropia Routine Diagnostic Visual acuity Refraction Tonometry Specialized diagnostic Fluorescein staining Intravenous fluorescein angiography Visual field test Tonometry This standard test determines the fluid pressure inside the eye. There are many types of tonometry. One type uses a purple light to measure pressure. Another type is the "air puff," test, which measures the resistance of the eye to a puff of air. Treatment and Diagnostice Procedures of the Eyes Visual acuity measurement Refraction Tonometry Dilation of the pupils using mydriatic drops Fluorescein staining Visual field test Intravenous fluorescien angiography Orbitotomy Tarsectomy Tarsorrhahpy Conjunctivoplasty Corneal transplant 0r keratoplasty Iridectomy Radial keratotomy (RK) Abbreviations relating to the eyes and ears OD – right eye OS – left eye OU – each eye or both eye AD - right ear AS – left ear AU – each ear or both ears The special Senses Medical specialties related to the Eyes and Ears Audiologist Ophthalmologist Optometrist Otorhinolaryngologist Structures of the Ears Outer ear • Pinna also known a auricle • Catches sound waves and transmit them into the external auditory canal • Cerumen or earwax Middle ear • Tympanic membrane or TM or eardrum Structures of the Ears Inner ear – also known as labyrinth contains the sensory receptors for hearing and balance Structures and functions Ears (acous/o, acout/o, audi/o, audit/o, ot/o) receptor organs for the sense of hearing; also help to maintain balance Outer ear (pinn/i) transmits sound waves to the middle ear Middle ear (myring/o, tympan/o) transmits sound waves to the inner ear Inner ear (labyrinth/o) receives sound vibrations and transmits them to the brain Pathology of the Ears Acute Otitis media Chronic otitis media The Special Senses Serous otitis media The Special Senses Mastoiditis otomycosis The Ears Diagnostic Procedures: Audiometry Audiometer Tympanometry Otoplasty SPECIAL SENSES: The Eyes and Ears The End