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Transcript
SENSES (EYE & EAR) & INTERGUMENTARY SYSTEM (SKIN) The Senses General Senses Distributed throughout body Pain Touch Pressure Temperature Proprioception Special Senses Located within complex sense organs Gustation = sense of taste Olfaction = sense of smell Hearing Equilibrium Vision The Ear Used for both hearing and equilibrium Divided into three parts Outer ear Pinna (auricle) External auditory canal (meatus) Contains cerumen (earwax) Tympanic membrane (eardrum) Transmits sound waves to middle ear The Ear (con’t) Middle ear Houses three ossicles Malleus (hammer) Incus (anvil) Stapes (stirrup) Soundwaves are transmitted from footplate of stapes Eustachian tube Connects middle ear to nasopharynx Equalizes pressure between outer and middle ear The Ear (con’t) Inner ear Complex labyrinth shape Filled with fluid Contains cochlea Organ of Corti Vestibular apparatus Sense of equilibrium Semicircular canals Vestibulocochlear nerve Cochlear branch transmits hearing impulses Vestibular branch transmits equilibrium impulses Otitis Inflammation of the ear Otitis media = infection leading to accumulation of fluid in middle ear Causes Obstruction of eustachian tube caused by Spreading infection Treatment Antibiotics Myringotomy Otitis (con’t) Otitis externa Inflammation of external auditory canal Also known as “swimmer’s ear” Caused by: Fungus Bacterium Common among: People living in hot climates Swimmers Meniere Disease Involves production and circulation of inner ear fluid Symptoms Vertigo (dizziness) Hearing loss Tinnitus (ringing in ears) Pressure Treatment Drugs (to treat nausea and dizziness) Severe cases Inner ear or eighth cranial nerve destroyed surgically The Eye and Vision Eye has three layers Sclera Outermost layer Known as “White of the eye” Extends over front of eye as transparent cornea Uvea Uvea Middle, vascular layer Consists of: Choroid Ciliary body Muscle controls shape of lens Allows for accommodation Iris Muscular ring Controls size of pupil Determines eye color Retina Innermost layer Actual visual receptor Consists of specialized cells: Rods Function in dim light Low visual acuity Do not respond to color Cones Active in bright light High visual acuity Respond to color Eye Protection Orbit = bony socket Eyelids Conjunctiva Thin membrane Covers anterior portion of eye Eyebrows Eyelashes Tears Lacrimal glands Bathe eyes with lubricating fluid Fluid drains into nose Errors of Refraction Myopia = nearsightedness Hyperopia = farsightedness Eyeball too long Images form in front of retina Eyeball too short Images form behind retina Astigmatism = irregularity in curve of cornea or lens Glasses can correct most of these impairments Infection Conjunctivitis = inflammation of conjunctiva Trachoma = inflammation of cornea and conjunctiva Commonly known as “pinkeye” Highly infectious Results in scarring Common cause of blindness in 3rd world countries Ophthalmia neonatorum = acute conjunctivitis in newborns Caused by gonorrhea Disorders of Retina Retinal detachment Separation of retina from choroid Caused by: Tumor Hemorrhage Injury to eye Repaired with laser surgery Cataract Opacity of lens caused by: Disease Injury Chemicals Exposure to UV rays Must be removed to prevent blindness Anterior capsule removed Phacoemulsification Glaucoma Increased pressure within eyeball More aqueous humor produced than can be drained away Leads to blindness Many causes Screening at routine eye exams Treatment Medication Surgery Integumentary system: THE SKIN, NAILS, & HAIR