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22 Cards in this Set
- Front
- Back
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What are some general things about taste and smell
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Taste is called gustation, and smell olfaction. Both use chemoreception-chemicals is solution. Gustatory-chemicals desolved in saliva. Olfaction-chemoreceptors respond to chemicals desolved in nasal mucosa. Taste & smell work together. In fact taste is mostly 80% smell
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Describe gustatation
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581: gustatory receptor is a taste bud, we have 10,ooo. Mostly on tongue, but also on soft palate. Sit on elevations called papillae (peg-like projections) 1) called fungiform raised areas or 2) called circumvallate located in back , not on top, but down in crevaces. 2 types of cells in the taste bud. Dark purple is gustatory cell, and the other light purple is a support cell to hold shape. At end of gustatory rec. cell are hairs called villa-the sensitive portion or receptor membrane of the gust. cells. That's where the dissolved chemicals touch the membrane or is perceived.Taste pore is where the tastant enters and starts a generator potential. Basal cells are stem cells that will replace the old gustatory cells Taste fibers of cranial nerve wrap around gust. cells synapsing and potentials getting info to the brains
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What are the 5 types of taste?
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taste is mostly smell.
1)sweet-sugars, amino acids, carbs, energy source. 2)sour-acids (H+), vitamins (C) 3) salts-NaCl, minerals (cu, Fe) 4) Umami- beef taste-aged cheese- 5)Bitter-spoiled food, nicotine & coffee we like. |
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What do the individual taste buds respond to?
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1-2 of each of the taste types.
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What 3 nerves pick up taste in pathway
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glosso pharayn, facaila, and vagus go through the solitary nucleus in the medulla oblongatoa to pons to thalamus to gustatory cortex in insula.
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What happens when we smell
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We can smell 10,0000 different smells. When we smell it passesover olf epithelium, smells atinuate,
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What is part of the olfactory
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Smell comes in passes over olfactant epithelium. olfactory bulb where The real olfactory nerves are the filaments. Olafactory gland makes nasal mucosa, bibolar olfactory receptor cellsw/ends that end up as olfactory cilia that detect olfactant that sets off a generator potential
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How long do olfactory cells last
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60 days and then basal cells will be stem cells that will come in an replace the old olfactory cells.
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What do the bipolar cells synapse with?
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Mitral cells, and the axons of the mitral cells go through the olfactory tract.
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What is the purpose of the cribriform plate?
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Olfactory filaments drop down through holes in cribriform plates
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Why do we have a variation in our smell.
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Because of the different combinations of mitral cells connecting, all sorts of combinations are possible
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What is the pathway of smell
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1)mitral cells>>olfactory tract>>>thalamus(olfactory cortex-I'm smelling OR to >>>hypothalamus-limbic system-emotional response. OR mitral cells>>>olfactory bulb>>>cells that release GABA (an inhibitory neurotransmitter) >>>inhibits bad smells, so we can smell something else.
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What is equilibrium?
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We have touch, vision, hearing, taste, smell, but what is the 6th sense? Equilibrium. Our ability to stand and balance. Organs of equilibrium are located in the vestibule and semicircular canals. We have 2 types of equilibrium 1)static-vestibule 2) dynamic-semicircular canals.
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describe Static equilibrium
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In the vestibule we have the Maculae (otolith organ) responds to straight line forces or linear acceleration-tells if I'm moving up, backward, forward.. detects changes in speed or direction. 2 compartments in vestibule. The one closest to cochlea is the saccule and utricle close to semi cir. In the utricle the macula is flat, but macula is in saccule standing up. Macula has hair cells that detect motion w/hair bundles, called stereocilia. Attached to the hair cells is vestibular nerves. All of this is similar to structures in cochlea. A membrane similar to tectorial is called otolithic membrane(like jelly) if membrane moves it deflects the hairs (longesst hair fiber is kinocilium and it tells you your position. Calcium carbonate called otolyths crystal stones are in the membrane that respond to movements. Gravity is the major force.
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pg 595 how does movemment det. occur. in utricle
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When we stand straight up, hairs are not bent, crystals are flat, keeps a med frequency. but when we bend head left (depolarization) otolith membrane will slip because of density of crystals, the hairs will deflect causing increased frequency, causing exictation telling the brain that you are at the left, tippd the other way that causes inhibition-hyperpolarizaion, frequency decreases, tells brain you moved to right.
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What happens in saccule?
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Response to vertical movements, response to gravity.
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What is dynamic equilibrium?
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Measuring rotational forces or angular acceleration (opposed to linear). To sense rotation in 3 planes (roll, pitch, or yaw-semi circ canals correspond to these planes. Canal has a membrane filled with endolymph w/bubble structures called ampulla-filled w/structure called cupula w/jelly and hairs, and fibers of vestivular nerve(combined called crista ampularis), when the hairs are deflected it tells the brain there is movement. When we move,endolymph will lag behind pulling hairs back which tells the brain which direction, unless we are moving and spinning constantly then hairs will straightnen sending message to brain that there is no movement, even thought we are, but then the fluid will keep moving, even though we've stopped.
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What are the 3 parts of the ear in general?
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outer, inner middle
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Describe the outer ear
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Consists of the auricle called the pinna- the part we see, what people call the ear, made of elastic cartilage, surrounds the opening of the external acoustic meatus& the pinna concentrates sound waves (air movement/vibration of molecules) into the ext. acoustic meatus. The pinna is similar to a funnel w/ EAM is the tube of the funnel.
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Describe the Middle Ear
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AKA TYMPANIC CAVITY. Has 8 parts. 1)TYMPANIC MEMBRANE-aka eardrum-thin connect tissue; the boundary between outer & middle ear. Sound waves that enter the EAM hit the tympanic membrane and make it vibrate>>>The eardrum transfers sound nrg (from air in motion to solids in motion) to the bones of the middle ear. 2)OVAL WINDOW: covered w/thing ct membrane. 3) ROUND WINDOW-covered w/thin ct membrane. 4)EPITYMPANIC RECESS-the roof of the middle ear cavity, where the tympanic cavity arches-not covered w/a membrane, creates an opening into the mastoid antrum; puts sound into mastoid antrum . 5)MASTOID ANTRUM-like honeycomb-a canal in posterior wlal of the tympanic cavity.Collects some sound waves entering the middle ear. Collects waves in open space & makes the sound enriched>>>much like what concert halls do to enrich sound. 6) PHARYNGOTYMPANIC TUBE/AUDITORY TUBE/EUSTACHIAN TUBE: connects the middle ear to the nasal cavity, enable the equalization of pressure. (equalizes pressure in middle ear w/external air pressure) swallowing or yawning opens the usually flattened tube pressure. Equalizing pressure is important cuz the eardrum vibrates freely only if the pressure on both of its surfaces is equal. Valsalva is a way of equalizing pressure on descent. Swallowing is helpful on ascent. 7) EAR OSSICLES: 3 tiny bones of the ear: malleus, incus, stapes. The stapes is attached ot the incus and part of it fits into the oral window. After sound hits the tympanic membrane, it vibrates it-vibrathes the malleus>>that taps on the incus>>that vibrates the stapes that has a base that fits into the oval window-that sets fluids of inner ear like a wave eventually exciting the hearing receptors that take the impulse to the brain to detect the sound . At the ossicles the movement of air( sound wave) is transferred to teh movement of solid/solids in motion. 8) TWO SKELETAL MUSCLES ASSOCIATED W/OSSICLES: 1)tensor tympani muscle: inserts on the stapes. when loud sounds move the ossicles a lot, these 2 muscles will contract reflexively (autonomic reflex) to keep bones from moving as much & in turn prevents damage to hearing receptors.
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Describe the labrynths of the Inner Ear
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Inner ear:AKA LABRYNTH has 2 divisions found in the cochlea. (boney & membraneus labyrinths) Boney labyrinth is found in the cochlea(it is open sapce filled w/ perilymph (fluid similar to CSF). Membraneus labyrinth: found in the boney labyrinth it is suspended in the boney labyrinth center by the perilymph. The interior fluid of the membraneus labyrinth=endolymph. Note perilymph and endolymph conduct sound vibrations & respond to forces that occur during body position changes. The apex is the end of the membraneus labyrinth; suspended in perlymph and the hilicotrema is around the tip of the apex; most distal part of the cochlea; the end of bony labyrinth filled w/perilymph.
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Describe the Cochlea
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The cochlea forms a region the bony labyrinth filled w/perilymph and membraneus membrane filled with endolymph. The cochlea is the size of a pea, coils 2 1/2 rotations (looks like a snail) houses the hearing receptor called the organ of corti (the chochlear duct/scala media is membraneus area going thru the chochlea where the organ of corti is sound. The organ of corti detects sound. The cochlear nerve innervates the cochlea=hearing. 3 chambers of the bony cochlea. 1)scala vestibuli-lies superior to the cochlear duct (scala media) & is a chamber continuouis w/the stapes/abut the oval window. is part of the bony labyrinth;filled w/ perilymph. 2)Scala Media (cochlear duct) filled w/endolymph is part of the membraneus labyrinth. Stria vascularis are cells that line the membraneus scala media-they make endolymph. 3)Scala tympani-inferior to the scala media. Part of bony labyrinth filled w/perilymph. ends @ the round window. Note: the scala vestibuli & tympani are continous w/each other and are both bony lab contain perilymph. Vesitibular membrane "roof" of scala media (chochlear duct) separates the scala vestibuli from scala media. Basilar membrane "the floor" of the scala media-supports the spiral organ of corti and plays a critical role in sound reception. The narrow & thick part is near the oval window (shorter section =higher pitch detected there). Wider and thinner area gets near the cochlear apex (longer length of membrane=lower pitch detected there.
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