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Special Senses:. Anatomy, Physiology, Pathology, Diagnostics, and Theraputics. The Five Special Senses:. Sight Hearing Touch Taste Smell. Some General Terms:. Accomodation Acuity Gustation (taste) Humor Olfaction (smell) Ossicle Photopigment (retina) Slit lamp Tunic.
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Special Senses: Anatomy, Physiology, Pathology, Diagnostics, and Theraputics
The Five Special Senses: • Sight • Hearing • Touch • Taste • Smell
Some General Terms: • Accomodation • Acuity • Gustation (taste) • Humor • Olfaction (smell) • Ossicle • Photopigment (retina) • Slit lamp • Tunic
Eye Anatomy: 3 tunics • Fibrous Tunic (outermost layer) • Protective • Sclera (white), cornea, conjunctiva • Vascular Tunic (middle layer = uvea) • Choroid (blood supply), iris, ciliary body • Pupil, lens, suspensory ligaments • Sensory Tunic (innermost layer) • Retina, fovea, macula
Fibrous Tunic: Structures • Sclera • Translucent to allow light through • Cornea • Anterior part of the sclera • No capillaries of its own • Conjunctiva • Also lines the inner surfaces of eyelids • Has capillaries
Vascular Tunic: Structures • Choroid • Pigmented, vascular layer • Has posterior opening for optic nerve • Limits amount of light entering • Iris • Anterior part of choroid • Regulates amount of light passing through pupil • Ciliary body • Circular muscle that produces aqueous humor • Attaches to a capsular sac that holds the lens
Vascular Tunic: Structures • Pupil • Opening in the vascular tunic to allow light in • Dilates and contricts • Lens • Focuses light • Changes shape with ciliary muscle action • Suspensory ligaments • Hold lens in place • Accomodation: changes in eye shape to allow focus
Sensory Tunic: Structures • Retina • Outer, pigmented layer over choroid • Inner, nervous layer, visual part • Rods • Function in dim light, sense black and white • Cones • Function in bright light, sense color
Sensory Tunic: Structures • Macula • Posterior aspect of retina • Provides central vision • Fovea • Depression or pit in the macula • Contains only cones
Other Structures of the eye: • Photopigment: visual pigment, undergoes chemical changes when light hits it • Stimulates rods and cones • Optic nerve • Interprets & transmits visual stimuli • Optic disc • Area of entrance of the optic nerve into the posterior part of the eye • Also contains blood vessel • “blind spot” No rods or cones here
Other optic structures: • Humor (fluids in the eye) • Types of humors • Aqueous humor • Fills anterior & posterior chamber • Made by ciliary body, drained through canal of Schlemm • Nourishment for lens & cornea, focuses light • Glaucoma = deficiency of aqueous humor • Vitreous humor • Thick, gelatinous, in vitreous chamber of globe • Helps to focus light
More Optic structures: • 6 muscles control coordinated eye movements • Conjunctiva • Lacrimal glands and canals • Near medical canthus of the eye • Make tears
Auditory Anatomy • External ear • Auricle (pinna) • External auditory canal • Cerumen = earwax • Middle ear (tympanic cavity) • Inner ear (labyrinth)
Auditory Anatomy • Middle ear • Connects with pharynx via Eustachian tube • Tympanic membrane (eardrum) TM • Ossicles (little bones) • Malleus (hammer) • Between TM and incus • Incus (anvil) • Between malleus and stapes • Stapes (stirrups) • Between incus and cochlea
Auditory Anatomy • Inner ear • Auditory Nerve • Cochlea • Snail-shaped structure filled with perilymph • Organ of Corti • Hearing structure made of hair cells • Oval window • Foot of the stapes rests on this
Auditory Anatomy • Inner Ear (continued) • Structures that maintain static and dynamic equilibrium • Labyrinth • Maze-like, fluid-filled structure • Semicircular canals • 3 in number • Vestibule • Joins cochlea to semicircular canals
Medical Word Elements: • Amblyo= dull, dim (amblyopia) • Blepharo= eyelid (blepharoplasty) • Coreo- or pupillo = pupil • Pupillary response • Conjunctivo- (conjunctivitis) • Corneo- or kerato- = cornea • Cyclo=ciliary body, or cycle
Medical Word Elements: • Lacrimo- or dacryo = tear or lacrimal • Glauco- = gray (glaucoma) • Irido- = iris • Oculo or ophthalmo- = eye • Opto- or optico- = eye • Photo- = light • Presbyo= old age (presbyopia)
Medical Word Elements • Retino- • Sclero- = sclera or hardening • Scoto- darkness (scotoma) • Vitro- = vitreous humor or body • Aqueo- = aqueous humor
Medical Word Elements: Hearing • Audio= hearing (Audiometry) • Auro- or oto- = ear (otitis) • Labyrintho- (Labyrinthitis) • Mastoido- = mastoid process (mastoiditis) • Myringo- or tympano- = tympanic membrane (myringotomy & tympanectomy)
Suffixes: Vision & Hearing • -opia or opsia = vision • hemianopsia • -tropia = turning • esotropia • -acusia or –cusis = hearing • Presbycusis, anacusia
Prefixes: • Exo- = outside or outward • exopthalmos • Hyper- = above or more than normal • Hyperopia (farsightedness)
Pathology: Eyes • Ametropia: refraction problems from failure of light to fall properly on the retina • Myopia: • Nearsightedness, globe is too long • Hyperopia/ hypermetropia • Farsightedness, globe is too short • Presbyopia • Aging effect, a type of farsightedness, 40-45 YOA • Astigmatism • Defective lens curvature, diffuse light contact with retina, less focused, visual acuity is not sharp
Pathology: Eyes • Cataracts • Proteinaceous opacification of lens • Impairs vision gradually • Over 50% in US over 65 YOA • Congenital form due to rubella (measles) in first trimester • Surgical treatment: • Phacoemulisification of lense (US or laser) • Implantation of intraocular lens (IOL)
Pathology: Eyes • Glaucoma • Aqueous humor does not drain through canal of Schlemm, intraocular pressure (IOP) increases and destroys optic nerve • Open-angle or closed-angle types • Blurry vision, erythematous eye, eye pain • Tonometer/tonometry: measures IOP • Treatment: miotics (constricts pupils) or surger
Pathology: Eyes • Strabismus (heterotropia) • Eye misalignment (exo- or esotropia, upward or downward deviation) • Both eyes do not focus on the same object • Loss of 3 dimensional perception (steropsis) • Amblyopia- childhood version, suppression of vision in the deviated eye • Treatments: corrective lenses, eye exercises, surgery
Pathology: Eyes • Macular degeneration • Deterioration of macula =central vision loss • For fine work, facial recognition, driving, reading • Most common type = age related (ARMD) • Wet type • Only 10% of pts • Neovascular type, vessel leak fluids that destroy cells • Laser photocoagulation-not permanent • Dry type • Drusen (yellow deposits of dried pigment cells) form on macula • Visual loss without total blindness
Pathology: Hearing/ears • Otitis Media • Inflammation of middle ear • Bacterial or viral • Frequent in pediatrics, associated with URI • Severe forms associated with mastoiditis or otopyorrhea, otoencephalitis • Antibiotics, analgesics, occasionally surgery (Tympanotomy, myringotomy)
Pathology: Hearing/ears • Otosclerosis • Ankylosis (hardening) of bones of middle ear • Usually the stapes • Symptoms: tinnitis, dizziness, progressive hearing loss (low tones especially) • Genetic tendency • Treatment is surgical
Oncology • Retinoblastoma • Children, familial • 30% bilateral • Treatment is enucleation & radiation • Melanoma • Usually in adults • Usually arises in the pigmented cells of the choroid, but also in the orbit, iris or ciliary body • Surgical treatment varies with tumor location
Diagnostic & Symptomatic Terms • Achromatopsia: color blindness • Chalazion: eyelid tumor, seb. Cyst • Conjunctivitis • Convergence: normal medial movements of the eyes to focus on same object • Diopter: measurement term of refraction • Ectropion: eversion of lower lid rim
Diagnostic & Symptomatic Terms • Exopthalmos • Hordeolum: sty, bacterial infection of sebaceous gland of eyelid • Nyctalopia: night vision • Nystagmus • Papilledema • Photophobia • presbyopia
Diagnostic & Symptomatic Terms: • Retinopathy • Visual field • Anacusis: deafness • Labyrinthitis • Meniere disease • Otitis externa
Diagnostic & Symptomatic Terms • Presbyacusis • Tympanostomy tubes (PE) • Tinnitus • vertigo
Procedures • Audiometry • Caloric stimulation • Tonometry • Visual acuity testing • Gonioscopy: exam of angle of anterior chamber (for glaucoma) • Opthalmoscopy or opthalmoscope
Procedures • Otoscopy (including pneumatic) • Retinoscopy • Fluorescein • Orthoptic training (eye movements)
Surgical Procedures: • Blepharectomy • Blepharoplasty • Cochlear implant • Cyclodialysis: surgical formation of opening to drain aqueous humor • Enucleation: removal of whole globe • Evisceration: sclera and cornea remain
Surgical Procedures • Keratotomy: corneal incision • Otoplasty: on pinna • Phacoemulsification • Sclerostomy: opening in sclera • Tympanoplasty (myringoplasty): often done for TM perforation
Pharmacology: • Antibiotics: often topical • Antiglaucoma drugs • Timolol, diamox, timoptic • Mydriatrics: to dilate pupil • atropine • Ophthalmic decongestants: OTC • Ophthalmic moisturizers: OTC
Pharmacology • Antiemetics (vertigo treatment) • Meclizine, Antivert • Otic analgesics • Auralgan • Wax emulsifiers • Debrox, hydrogen peroxide