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Special Senses
Stack #72508
Question | Answer |
---|---|
Special Senses | oSenses allow body to react to the environment oSee, hear, taste, smell, and to maintain balance oBody structures receive sensation, nerves carry to brain, brain interprets and responds to message |
Eye | oSense of sight oLight rays transmitted to the optic nerve oOptic nerve relays information to brain for interpretation |
Bony Socket | houses eye, protects structures |
Eyelids & Eyelashes | protects from dirt/germs |
Lacrimal Glands | (tears) moisten/cleanse |
Conjunctiva | mucous membrane- lines eyelids and covers front of eye |
Sciera | outer tough membrane |
Cornea | circular/transparent structure in front of the sciera; allows light to enter the eye |
Choroid Coat | laced with blood vessels; nourishes the eye |
Retina | laced with blood vessels; nourishes the eye made of many layers of nerve cells which transmit light impulses to optic nerves |
Cones | sensitive to color; vision when light |
Fovea Centralis | area of sharpest vision |
Rods | used for vision when it is dark or dim |
Iris | muscular round structure- the “color of your eye”; control pupil size; light regulation |
Pupil | opening in the center of iris (black) |
Lens | behind pupil; light refraction (bend) to focus on the retina |
Aqueous Humor | clear watery fluid located between cornea & iris |
Vitreous Humor | jellylike fluid that fills the area behind the lens; maintains eye shape |
Muscles | provide eye movement |
Amblyopia | “lazy eye” Poor vision in 1 eye caused by dominance of the other eye If not treated by age 9 or earlier; blindness in 1 eye |
Astigmatism | Abnormal shape of cornea; blurred vision Corrective lenses for treatment |
Cataract | Cloudy or opaque lens Caused by aging or trauma Will see “halos” around lights; vision loss, milky pupil Treatment with surgery |
Hyperopia | farsightedness; difficulty seeing things up-close |
Myopia | nearsightedness; difficulty seeing things from far away |
Prebyopia | “old eye”; usually farsightedness |
Strabismus | “crossed eyes” |
Conjunctivitis | “pink eye” Contagious inflammation of conjunctiva caused by bacteria or virus (usually) |
Glaucoma | Increased intraocular pressure Occurs after 40 years old Most common cause of blindness Loss of peripheral vision; loss of night vision |
Ear | Controls hearing & balance |
Hearing & Balance | Sound waves transmitted to the auditory nerve |
Ear consists of: | •Outer Ear •Middle Ear •Inner Ear |
Pinna or Auricle | elastic cartilage with outer skin covering |
Auditory Canal | glands produce cerumen (wax) |
Tympanic Membrane | “eardrum” Separates outer ear from middle ear Vibrates to transmit sound waves to middle ear |
Middle Ear | 3 auditory ossicles •Transmit sound from tympanic membrane to inner ear oMalleus oIncus oStapes |
Eustachian Tube (ET) | oConnects to pharynx oFunction: allows air to enter middle ear; helps equalize air pressure on both sides of Tympanic Membrane |
Oval Window | membrane that separates inner from middle ear |
Vestibule | entrance to inner ear |
Cochlea | snail shell shaped •Contains “hairs” that compose the organ of Corti (receptors of sound waves) |
Organ of Corti | oTransmits impulses from sound waves to the auditory nerve oAuditory nerve transmits impulses to temporal lobe of verebrum, where they are interpreted as hearing |
Semicircular Canals | maintains balance |
Hearing Loss | •Conductive- waves not conducted to inner ear •Sensory- nerve damage |
Meniere's disease | •Inner ear disease- tinnitus, vertigo |
Otitis Externa | “swimmers ear” |
Otitis Media | middle ear infection |
Myringotomy | incision of the tympanic membrane with possible insertion of PE tubes (pressure equalizing) |
Otosclerosis | hardening of the ear structures (stapes) |
Sense of Taste | taste receptors located on the tongue |
Four Main Tastes | Sweet Salty Sour Bitter |
Sense of Smell | oNose is the organ of smell oOlfactory receptors in nasal cavity oImpulses carried from the olfactory nerve to the brain for interpretation oHumans can detect over 6,000 smells |
Skin & General Sense | oSense receptors for pressure, heat, cold, touch, and pain located in the skin and connective tissue oAllow the human body respond to its environment oHelp body react to conditions that could cause injury |
3 auditory ossicles | •Transmit sound from tympanic membrane to inner ear oMalleus oIncus oStapes (stirrup) |