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Thomadaki Neuro II
NYCC Thomadaki neuroscience final exam material SP10
| Question | Answer |
|---|---|
| sound waves are produced by periodic variations in _______________ | air pressure (waves travel 343m/sec or 767 mi/hr) |
| what is the speed of sound | 343m/sec |
| sound is characterized by its | frequency and intensity |
| sound __________determines pitch. | frequency |
| frequency determines ________. | pitch |
| how is frequency measured? | cycles per second or HERTZ |
| audible frequencies for humans are between _____________ HX | 20-20,000HZ |
| what has a frequency of more than 20kHz and may be heard by dogs, cats, mice and dolphins? | ultrasound |
| what has a frequency of less than 20Hz and may be heard by elephants and whales? | Infrasound |
| What kind of low frequency sounds have been implicated in car sickness, infrasound or ultrasound? | infrasound (low frequency) |
| low frequency sounds | infrasound |
| high frequency sound | ultrasound |
| humanly audible Hz | 20-20kHz |
| frequency determines | pitch |
| pitch is determined by | frequency |
| how many functional divisions of the ear? | 3 |
| name the 3 functional divisions of the ear | external, middle, inner (duh, you though that would be harder, didn't you?) |
| 2 parts of the external ear | pinna (auricle/tragus) and EAM (external acoustic meatus/auditory canal) |
| function of the pinna/auricle/tragus | sound capture |
| function of the EAM | tranfers sound to eardrum (2.5cm long) |
| what is in the middle ear | air, tympanic membrane, 3 ossicles and the tensor tympani and stapedius muscles |
| name muscles of middle ear | tensor tympani and stapedius muscles |
| name 3 ossicles of middle ear | stapes, malleus, incus |
| nerve of middle ear | chorda tympani of VII |
| inner ear is also called the | labyrinth |
| the inner is filled with ________, unlike the middle ear which is filled with ______. | fluid, air |
| the labyrinth is a fluid-filled ___________ | membrane |
| parts of labyrinth | cochlea and vestibule |
| another name for cochlea of inner ear | auditory system |
| a tube spiraling 2.5 times around the conical bony modiolus | cochlea |
| conical bony modiolus | the spiral-shaped bone of the labrynthine cochlea |
| 2 parts of inner ear/labyrinth | cochlea and vestibule |
| how is the tympanic membrane positioned inside the middle ear, regarding its conical shape | bowl-side (convex) inward |
| what ossicle is attached to the tympanic membrane | malleus |
| how is sound transmitted by the middle ear? | sound waves cause displacement of tympanic membrane (vibrate it) and this is transmitted to the ossicles |
| what holds the malleus, incus and stapes together? | tiny synovial joints |
| how does the tympanic displacement get transferred to the inner ear? | the stapes footplate pistons in and out onto the oval window, transferring the tympanic membrane displacement to the inner ear |
| connection between middle ear and nasopharyx | eustachian tube (pharyotympanic tube)also called auditory tube |
| how is the Eustachian tube usually closed off? | a valve and the mastoid air space (antrum) via the aditus |
| antrum | mastoid air space |
| what is the function of tensor tympani and stapedius muscles? | attached to tympanic membrane and stapedius, they dampen loud sounds (ergo, a prob. will present as hyperacousis) |
| hyperacousis | the perception of sound as very loud due to the malfunction of the tensor tympani or stapedius muscles or their respective innervation |
| by how much do the inner ear muscles dampen sound? | 10dB |
| Why doesn't the sound-dampening capability of tensor tympani and stapedius protect us from sudden loud sound? | the attenuation reflex has a 50-150msec delay |
| sound has to travel from air-filled external ear to fluid-filled inner ear. What is the function of the middle ear? | enhance the pressure so that the signal is not lost in translation/transition from air to fluid. |
| If the middle ear did not function to enhance the pressure required to transfer the signal, what would happen? | only 2% of the sound energy would be transferred from the external to inner ear as compared to the 67% that actually is transferred. |
| By how many times does the middle ear amplify pressure? | 22x |
| How does the middle ear amplify pressure by 22x? (2 ways) | 1-surface of oval window is 17x smaller than the tympanic membrane surface, 2-the ossicles act as levers and increase the force output on the oval window |
| the movement on the footplate of the stapes is 1.3 times the movement of the ? | arm of the malleus |
| 2 ways middle ear amplifies pressure | oval window is 17x smaller than tympanic membrane and ossicles act as levers to increase force output on oval window, essentially the fire hose becoming a garden hose (speed increases inverse to size of opening/tube) |
| a little oval window means | a lot of sound forced through an opening that started out the size of the external acoustic meatus |
| name the two membrane-covered holes at the base of the cochlea facing the middle ear | oval window and round window |
| what causes fluid movement inside the middle ear? | displacement of the oval window by the stapes |
| what ossicle displaces the oval window, causing fluid movement? | stapes |
| Where is movement of fluid (via displacement of oval window by stapes) absorbed in the middle ear? | fluid in the cochlea |
| what causes distortion of the round window? | unabsorbed energy by the cochlea from the oval window |
| 3 fluid-filled chambers of the cochlea: | scala vestibuli, scala media, scala tympani |
| name the 3 fluid-filled scala of the cochlea... | vestibuli, media, tympani |
| Where is Reissner's membrane? | between the s. vestibuli and s. media |
| sv/R/sm | scala vestibuli/Reissner's/scala media |
| If Reissner's membrane is between the s.vestibuli and s.media, where is the BASILAR membrane? | between s. media and s. tympani |
| the scala _________(containing perilymph), which lies superior to the cochlear duct and abuts the oval window | vestibuli |
| the scala _______ (containing perilymph), which lies inferior to the scala media and terminates at the round window | tympani |
| the scala _______(containing endolymph), which is the membranous cochlear duct containing the organ of Corti | media |
| the scala media (containing __________), which is the membranous cochlear duct containing the organ of Corti | endolymph |
| the scala vestibuli (containing _________), which lies superior to the cochlear duct and abuts the oval window | perilymph |
| the scala tympani (containing __________), which lies inferior to the scala media and terminates at the round window | perilymph |
| scala tympani + perilymph terminates at the _________window | round |
| scala vestibuli + perilymph abuts the ________window | oval |
| scala media + endolymph is the membranous cochlear duct and contains the _____________ | organ of Corti |
| the _________ membrane, a main structural element that separates the scala media from the scala tympani and determines the mechanical wave propagation properties of the cochlear partition | basilar |
| the basilar membrane, a main structural element that separates the scala media from the scala tympani and determines the _______ __________ propagation properties of the cochlear partition | mechanical wave |
| the Organ of Corti, the ________ epithelium, a cellular layer on the basilar membrane, powered by the potential difference between the perilymph and the endolymph | sensory |
| the ____________________, the sensory epithelium, a cellular layer on the basilar membrane, powered by the potential difference between the perilymph and the endolymph | organ of Corti |
| the Organ of Corti, the sensory epithelium, a cellular layer on the basilar membrane, powered by the potential difference between the __________ and the __________. | perilymph and the endolymph |
| describe PERIlymph molecularly | lots of Na+ (therefore low in K) |
| describe endolymph molecularly | high in K (ergo, low in Na) |
| which is higher in K+, endo- or perilymph? | endo (K-endo media) |
| periNa | perilymph is high in Na+ (like Purina) |
| the Scala vestibuli and tympani contain perilymph, which means these areas are high in ? | Na (periNa) |
| The scala media is low in Na+ so it contains | endolymph which is high in K (K-endo media) |
| K-endo media | K endolymph {scala} media |
| hair cells, sensory cells in the Organ of Corti, topped with hair-like structures called ___________- | stereocilia |
| what is the upper chamber of the cochlea which first receives vibration from the stapes via the oval windo? | scala vestibuli's perilymph |
| Think of the cochlea as a long tube that's been divided into 3 chambers (like a peace sign) for it's entire length. The peace sign is on it's side, so what scala's perilymph gets the first vibrations and how? | scala vestibula is connected to oval window, so when stapes knocks on oval window, the sound waves are tranferred into the s.vestibuli's perilymph first. |
| We know the scala vestibuli contains perilymph and is the first "slice" of the peace sign contacted via the oval window. What molecule is abundant in scala vestibuli? | Na+ (because K-endo media) |
| what connects the s. vestibuli with the other perilymph-containing chamber, the s. tympani? | helicotrema |
| where is the helicotrema that connects both the perilymph containing chambers of the cochlea? | at the apex of the cochlea (this is the connection between s. vestibuli and s. tympani) |
| scala media is aptly called the | cochlear duct (in older texts) |
| where is scala media/cochlear duct within the "peace sign" layout of the cochlea? | it is the smallest chamber of the 3 scalae |
| what kind of perilymph does the s. media contain and what molecule is it rich in? | endolymph, K (K-endo media) |
| The two scalae (fluid-filled chambers) communicate with each other through an opening at the top (apex) of the cochlea called the ___________, a common space that is the one part of the cochlea that lacks the lengthwise dividing membrane. | helicotrema |
| The walls of the hollow cochlea are made of bone, with a thin, delicate lining of epithelial tissue. This coiled tube is divided through most of its length by a ________partition. Two fluid-filled spaces (scalae) are formed by this dividing membrane. | membrane |
| The helicotrema (from Greek ἕλιξ meaning coil and τρη̂μα meaning hole) is the part of the cochlear labyrinth where the scala tympani and the scala vestibuli meet. It is the main component of the cochlear apex. The hair cells in this area best detect ? | low frequency sounds |
| Tonotopy (from Greek tono- and topos = place) refers to the ? | spatial arrangement of where sounds of different frequency are processed in the brain |
| tonotopy is how the ________ is arranged. | cochlea |
| Tones close to each other in terms of frequency are represented in topologically neighbouring regions in the brain. | Tonotopy in the auditory system begins at the cochlea, the small snail-like structure in the inner ear that sends information about sound to the brain |
| Different regions of the basilar membrane vibrate at different sinusoidal frequencies. The auditory nerves that transmit information from different regions of the basilar membrane therefore encode frequency tonotopically. | This tonotopy is maintained in the human vestibule cochlea nerves cortex, that part of the brain that receives and interprets sound information |
| sounds of low pitch project into the anterolateral aspect of Heschl's gyrus, while sounds of high pitch project deeply into the lateral fissure (which houses Heschl's gyrus | tonotopy |
| What is responsible for the layer of membrane in the s. media secreting ions of potassium (K) while absorbing sodium against the concentration gradients of both? | stria vascularis |
| stria vascularis | responsible for secreting K and absorbing Na in the s. media (the only one that has extra K to kick out!) |
| which chamber is the lower one in the cochlea? | scala tympani |
| Where is the Organ of Corti located? | on the basilar membrane |
| This motion of perilymph in turn vibrates the endolymph in the scala media, the perilymph in the scala tympani, the basilar membrane, and organ of Corti, thus causing movements of the hair bundles of the hair cells, acoustic sensor cells that convert? | vibration into electrical potentials. |
| The hair cells in the organ of Corti are tuned to certain sound frequencies[1], being responsive to high frequencies near the oval window (______) and to low frequencies near the apex of the cochlea. | base (oval window is base) |
| The spatial arrangement of sound reception (high freq. at base/oval window and low freq. at apex/hilicotrema)is referred to as tonotopy. | tonotopy |
| The ______________ is the organ in the inner ear of mammals that contains auditory sensory cells, or "hair cells." | organ of Corti (spiral organ) |
| basilar membrane is narrow at the base and therefore the base can only detect _______ frequencies | high |
| the narrow end of the basilar membrane is ________ at the base, while the wide end is _______ at the apex. | rigid (narrow) base, floppy (wide)apex |
| rigid narrow base high is to | floppy wide apex low |
| rigid narrow base detects ________ frequencies | high |
| floppy wide apex detects _________frequencies | low |
| the narrow rigid base collecting high frequencies while the floppy wide apex collects high frequencies is reflected in the organization of the transverse temporal gyri of Heschel. What is the name for this continuity? | tonotopic map |
| what sits on the basilar membrane of the cochlea? | auditory sensory cells (hair cells) covered by the tectorial membrane |
| what membrane covers the auditory sensory cells (hair cells) as they sit upon the basilar membrane of the cochlea? | tectorial membrane |
| there is a narrow ______ on a vase. | base |
| the base of the basilar membrane codes? | loud high frequency sounds |
| where is the Organ of Corti? | on the basilar membrane |
| The Organ of Corti, sitting on the basilar membrane, is the sensory receptor organ of hearing. It has 5 structures: | inner hair cells, outer hair cells, rods of Corti (pillars), supporting cells, tectorial membrane covering |
| In what chamber is the Organ of Corti? | scala Media (k-endo media) with endolymph of K+ |
| rods of Corti are also called | pillars of Corti |
| What structure of what structure of the Organ of Corti bends to produce a receptor potential? | stereocilia of a hair cell of the Organ of Corti |
| how many stereocilia per Organ of Corti hair cell? | 100 |
| How many inner hair cells? | 3500 |
| How many outer hair cells? | 12,000 |
| approx. ratio of inner hair cells to outer hair cells | 1.5:4 |
| where are the 3500 inner hair cells of the Organ of Corti | in a row located between the pillar (rod) cells of Corti and the bony modiolus |
| what is a bony modiolus? | The walls of the hollow cochlea are made of bone, with a thin, delicate lining of epithelial tissue |
| The hair cells are arranged in four rows in the organ of Corti along the entire length of the cochlear coil. ________ rows consist of outer hair cells (OHCs) and _____ row consists of inner hair cells (IHCs | three, one |
| The _______ hair cells provide the main neural output of the cochlea. | inner |
| which hair cells provide the main neural output of the cochlea? | inner |
| The outer hair cells, instead, mainly receive ______________________________, which influences their motility as part of the cochlea’s mechanical pre-amplifier | neural input from the brain |
| which hair cell receives neural INput from the brain | outer |
| What nucleus of the brain is the primary output to the outer hair cells of the cochlea? | olivary body/nucleus via medial olivo-cochlear bundle |
| Inner Hair Cells (IHC) number 3500 between the pillars and modiolus. Their stereocilia extend into the _________ inferior to the tectorial membrane. | endolymph |
| What structure's structures (hahaha I know) extend into the endolymph below the tectorial membrane? | the stereocilia of IHC |
| do inner hair cells INput or OUTput? | OUTput |
| In goes Out and Out goes In (explain this in regards to hair cells) | Inner hair cells = Output, Outer hair cells = Input |
| There are 12,000 OHC (Outer Hair Cells) receiving neural input from the olivary nucleus. Where are these little soldiers located? | distal to the pillar/rod cells of Corti |
| How far does the stereocilia of an OHC extend into the endolymph? | all the way to the tectorial membrane! |
| basilar membrane vibrations induce recpetor potential in the HC's of the corresponding cochlea region. Of the two rows of HC's, the inner row cells act as true ____________________. | true auditory receptors |
| Hair cells synapse with dendrites of ________ spiral ganglion cells located in the modiolus and whose axons form the Cochlear nerve (1/2 of VIII). | bipolar |
| Hair cells synapse with dendrites of bipolar _______ ganglion cells located in the modiolus and whose axons form the Cochlear nerve (1/2 of VIII). | spiral |
| Hair cells synapse with dendrites of bipolar spiral ganglion cells located in the _________ and whose axons form the Cochlear nerve (1/2 of VIII). | modiolus |
| Hair cells synapse with dendrites of bipolar spiral ganglion cells located in the modiolus and whose _______ form the Cochlear nerve (1/2 of VIII). | axons |
| Hair cells synapse with dendrites of bipolar spiral ganglion cells located in the modiolus and whose axons form the ______________(1/2 of VIII). | cochlear nerve |
| What converts the mechanical energy that reaches the inner ear to a receptor potential? | Hair cells |
| Hair cells convert the mechanical energy that reaches the inner ear to a _______________. | receptor potential |
| Hair cells + mechanical energy = | receptor potential |
| What causes all the structures of the Organ of Corti to move either up or down, causing the stereocilia to bend sideways in one direction or the other? | When the basilar membrane is affected by the scala's fluid movement |
| Downward movement of the basilar membrane causes | hyperpolarization. (shut down) |
| hyperpolarization of the hair cells is caused by what movement? | downward |
| what happens during upward movement of the basilar membrane? | Stereocilia bend so the K channels on their tips open and depolarize the hair cells. |
| upward basilar movement means | depolarization due to stereocilia K channels opening |
| After upward basilar membrane causes stereocilia to open K channels and depolarize hair cell, what happens? | Calcium! channels open and neurotransmitters (maybe glu)are released. A synapse then occurs between the Hair cells and the dendrites of the spiral ganglion |
| There are approximately _________ spiral ganglion cells, most of which receive synapses from the inner hair cells. | 30,000 |
| From where do the 30,000 spiral ganglion cells receive their synapses? | Inner Hair Cells (remember, inner is output) |
| Which cells are responsible for pathological hyperacousis? | Outer hair cells, because they increase the movement of inner hair cells which in turn output a crapload of synapses to the spiral ganglion and BOOM! hyperacousis!) |
| what kind of ganglia do hair cells synapse upon to conduct receptor potential? | spiral |
| Spiral ganglia = | hair cells |
| The axons of the ________ ganglion cells form the cochlear nerve, which follows the tonotopic organization of the basilar membrane. | spiral |
| the Axons of the spiral ganglion cells form the _________ nerve. | cochlear nerve (1/2 VIII) |
| The Cochlear nerve/axons of spiral ganglion follow tonotopic organization of the basilar membrane, which means that each fiber is most responsive at a specific ___________. | frequency. |
| The tonotopic org of cochlear nerve/axons of spiral ganglion means that nerves coming out of the apex basilar membrane will, like the hair cells present in the apex, respond to ___________ frequency. | low (and the spiral ganglion/cells of the cochlear nerve coming out of BASE hair cells will respond to HIG frequencies because it is "base shaped like a vase is high falutin'!" |
| the spiral ganglion/cochlear nerves are going to travel to the _________ and synapse with the cochlear nuclei. | medulla |
| There are two _________ and one ________ cochlear nuclei. Each has 2 types of cells. | 2ventral, 1dorsal |
| Ventral cochlear nuclei have ______ cells and _______ cells. | stellate & bushy |
| There are ____ ventral cochlear nuclei and they have __________ cells and _________ cells. | 2, stellate, bushy |
| 2 thorny bushes in the front of the house. | 2 ventral cochlear nuclei with stellate and bushy cells. |
| Stellate cells of the 2 ventral cochlear nuclei encode a variety of ___________. | grequencies |
| Bushy cells of the 2 ventral cochlear nuclei fire at the onset of sound and AID in the ____________ of sound along a HORIZONTAL AXIS. | LOCALIZATION |
| bushy ventral cochlear nuclei cells aid in the | localization of sound on the horizontal axis |
| stellates are the transponders and bushies are the guns and sighting. | stellates encode frequencies and bushies fire at onset of sound and localize the sound in the horizontal axis. |
| THe dorsal cochlear nucleus has ________ cells and _________________ cells. | fusiform, tuberculoventral |
| fusiform | bundled, like muscle cells |
| The dorsal cochlear nucleus has _________ cells that get excited or inhibited by a wide variety of frequencies and AID in sound localization along the vertical axis. The dorsal nucleus also has ________________ cells. | fusiform, tuberculoventricular |
| fusiform = | vertical axis location for dorsal cochlear nucleus |
| _________________ cells of the dorsal cochlear nucleus respond with a delay and inhibit echo interference. | Tuberculoventricular |
| which cells localize sound in the horizontal axis? | bushy cells of the ventral cochlear nuclei |
| which cells localize sound in the vertical axis? | fusiform cells in the dorsal cochlear nucleus. |
| which cells respond with a delay and inhibit ECHO interference? | tuberculoventricular cells in dorsal cochlear nucleus. |
| which cells transpond/encode a lot of frequencies? | stellates in the ventral cochlear nuclei |
| stellate, bushy, fusiform, tuberculoventricular | cells of the ventral cochlear nuclei (2) and dorsal cochlear nucleus (2) respectively. |
| The cochlear nuclei synapse bilaterally with the | SON of an Inferior Colliculus! |
| SON | Superior Olivary nucleus |
| The cells of the cochlear nuclei will bilaterally synapse with the | SON (Superior Olivary Nucleus) |
| SON, the docking station for cochlear nuclei, achieves localization of the sound source along the ___________ axis by processing the auditory time delay between the two ears. In other words, what does the SON do? | decides if the sound came from the left or right side. |
| When is the delay between the two ears (interaural time delay) detected by the SON most apparent? | low frequencies. (ie, you can tell which side the sound came from/horizontal axis detection if the frequency/pitch is LOW |
| It is difficult to distinguish _______ frequencies on the horizontal axis based on the interaural time delay. | high |
| The SON not only detects which side the sound came from (horizontal axis) but processes the intensity difference between the two ears. Intensity interaural differences are most striking at ______frequencies. | high |
| Intensity differences are most striking at high frequencies because | there is a higher rate of firing of nerve impulses from the associated auditory fibers, then to the cochlear nuclei, then to the SON. Auditory centers dtermine loudness by comparing firing of one auditory n. to one that is resting. |
| SON is intraural time differences (horizontal axis/left or right side sound source) via ______ frequencies and intensity difference via _____ frequencies. | low (left/right), high (intense) |
| low (left/right), high (intense) is | SON |
| Fibers from the SON form the _______________ | lateral lemniscus. |
| Some SON fibers are going to synapse with the lateral lemniscus nucleus, but most are going to synapse with the | Inferior colliculus |
| The inferior colliculus, target of most of the SON fibers, has a 4-layered dorsal nucleus that gathers ___________&_________ info, and a multilayered central nucleus that has a complete ______________________. | auditory & somatosensory, tonotopic map |
| From the inferior colliculus, sound fibers travel along the ____________________ to the Medial geniculate body. | inferior brachium |
| Medial geniculate body via inferior brachium from the inferior colliculus. The MGB holds a complete __________ map. | tonotopic |
| From MGB, where do fibers go? | Auditory radiation to end in PAC |
| PAC | primary auditory cortex |
| Broadmann's areas 41 and 42 | Transverse temporal gyri of Heschl |
| Broadmann's areas 41 and 42 located near the superior temporal gyrus | Transverse temporal gyri of Heschl |
| Is the transverse temporal gyri of Heschel tonotopically organized? | yes |
| What is the second point of determining sound localization? | Transverse temporal gyri of Heschl |
| What are the two structures that determine sound localization | SON and TTGHeschl |
| It has columns that are responsive to every audible frequency and interaural relationship. | TTGHeschl |
| A lesion to the SON or the TTGHeschl | means we cannot localize the source of the sound |
| Conductive hearing loss results from an insult to the _______ ear. | middle |
| _____________hearing loss results from an insult to the middle ear. | Conductive |
| What may result in formation of scar tissue that hinders the movement of the tympanic membrane or the ossicles? | Otitis media |
| What disease may result in ossification of the attachment between the ossicles? | Otosclerosis (a disease with no known cause) |
| What two kinds of Conductive hearing loss? | Otitis media and Otosclerosis |
| What kind of hearing loss results from loss of cochlear hair cells? | Sensorineural hearing loss |
| Sensorineural hearing loss results from the loss of | cochlear hair cells |
| Place a tuning fork on vertex or nasion (along the midline of the skull). The sound lateralizes to the ear with the conductive deafness OR away from the ear with sensorineural deafness. | Weber's test |
| During Weber's test, the sound lateralizes to the ear with ______________. | Conductive hearing loss (Conduct means "to" so the sound is "conducted to" the side of hearing loss during Weber's test) |
| During Weber's test, the sound lateralizes AWAY from the ear with | Sensorineural hearing loss AWAY |
| Rinne my bell | Rinne's test is a tuning fork up against the mastoid, and when patient can no longer hear it, place fork next to ear. Should hear it. If cannot, then conductive loss expected. |
| What kind of loss is expected with a positive Rinne's test? | conductive |
| 3 parts of labyrinth | cochlea, vestibule (utricle and saccule), semicircular canals |
| The vestibule 2 parts | utricle and saccule |
| The bony labyrinth contains ____________ which is rich in _____. | perilymph, Na+ |
| What kind of fluid does the bony labyrinth contain and what other part of the ear contains this fluid, too? | perilymph (Na+) is contained in the bony labyrinth of the inner ear and the sacula vestibuli and sacula tympani of the middle ear. |
| If the bony labyrinth contains perilymph (Na+), what does the membranous labyrinth contain? | endolymph (K) |
| Why does the membranous labyrinth containing endolymph/K communicate with the endolymphatic sac? | the sac continually absorbs the continually produced endolymph |
| posture, muscle tone, eye position with respect to head motion are all functions of the ______________ system. | vestibular |
| 2 divisions of Vestibular system: | Static & Kinetic |
| composed of utricle and saccule | Static labyrinth |
| detects static orientation of the head with respect to gravity, includes utricle and saccule | Static labyrinth |
| Specialized cells in Static labyrinth are called ________ utricle and _______ saccule. | macula |
| Static labyrinth has ________ cells. | Macula |
| macular utricle and macula saccule are in the ____________ labyrinth of the vestibular system. | Static |
| The hair cells in the maculae of the Static labyrinth are embedded in a gelatinous mass called the ___________, which contains CaCO3 crystals. | otolithic |
| What kind of crystal/mineral does the otolithic membrane of the Static labyrinth contain? | CaCO3 (calcium carbonate) |
| Static labryinth association words | vestibular, saccule, utricle, macula, otolithic membrane, calcium carbonate |
| Kinetic labyrinth implies | movement! |
| Labyrinth composed of semicircular canals which detect angular acceleration and deceleration. | Kinetic |
| The semicircular canals of the Kinetic labyrinth are ______________-oriented so they can detect motion in all possible directions. | orthogonally (right angles to one another) |
| The ends of each the semicircular canals of Kinetic labyrinth | ampullae (each ends in an enlarged bell shape) |
| word associate Kinetic labyrinth | vestibular, ampullae, crista ampullae, cupula, semicircular canals, orthogonal |
| Name of the specialized hair cells in the semicircular canal ampullae? | crista ampullaris |
| The Static maculae are embedded in a gelatinous mass called the otolithic membrane (CaCO3). What are the special hair cells of the Kinetic labyrinth embedded in? | cupula |
| The whole thing is called the ampullae, and within it the special kinetic hair cells are called crista ampullae. They are contained in an upside down cup called the _________. | cupula |
| Transduction in the vestibular sys is the same as in the cochlear system because the two are continous. What, exactly, IS continuous between them? | endolymph (K) |
| What causes hair cell DEpolarization? | K (potassium) |
| Potassium causes | hair cell DEpolarization |
| Hair cells (crista ampullae and maculae, both) have microvilli on one end with a longer ____________ on the opposite end. | Kinocilium |
| IF the microvilli bend toward the kinocilium and pay homage, what happens? | DEpolarization |
| If the microvilli ignore the kinocilium and lean away, what happens? | hyperpolarization |
| After DEpolarization, the hair cells have receptors that synapse with dendrites of __________cells called vestibular ganglia or ___________ ganglia. | bipolar, Scarpa's |
| Scarpa's ganglia synapsing with the static and kinetic labyrinth hair cells have the axons which form the ____________nerve. | vestibular |
| associate Scarpa's | bipolar vestibular ganglion whose axons form the vestibular nerve and whose dendrites synapse with the hair cell receptors of either maculae or crista ampullaris |
| Where to after vestibular axons from Scarpa's ganglion? | enters brainstem at the cerebellopontine angle lateral to facial nerve |
| Where are the vestibular nuclei? | under the vestibular area in the 4th ventricle space/"lateral aspect of the floor of the medullary and pontine part of fourth ventricle, underlying the vestibular area" |
| 4 projection areas of Vestibular nuclei: | floccunodular lobe and fastigial nucleus of cerebellum (go together always for proprioception), spinal cord vestibulospinal tract, and the brainstem nuclei of III, IV, VI bilaterally via the MLF, and finally the VPN of thalamus so it gets to the parietal. |
| What is implied by vestibular nuclear projections to Oculomotor, Trochlear and Abducens nerves? | Your proprioreceptive balance much affects your eye movement, thankfully! |
| 4 vestibular nerve nuclei projections | flocculonodular lobe/fastigial nucleus of cerebellum, vestibulospinal tract of spinal cord, brainstem nuclei of III,IV, VI via the MLF (eye movement), and finally to VPN of thalamus so to parietal assoc. areas of cortex |
| How does vestibular info get to the parietal association areas of the cortex? | via the vestibular nuclei projection to the VPN of thalamus |
| internuclear ophthalmoplegia | III,IV and VI fail! to carrout synchronous horizontal gaze due to MLF lesion |
| Internuclear ophthalmoplegia is seen in what kind of patients? | MS or vascular disease |
| Is internuclear ophthalmoplegia specific to vestibular disease? | NO! |
| lesion to MLF | internuclear ophthalmoplegia |
| rotates 10x in 20 sec., patient flexes forward 30degrees, rotation stops abruptly. An intact Vestibular system will produce? | Barany chair: nystagmus! (named for fast component) opposite rotation. |
| Barany chair intact system produces | nystagmus during opposite rotation |
| warm or cold water in external acoustic meatus | Caloric testing |
| Warm water produces nystagmus in _________ side in an intact vestibular system. | same (WSI is Warm Same Intact) |
| Cold water produces nystagmus in the ____________ side of an intact vestibular system. | opposite is COW Cold Opposite Water |
| vestibulo-ocular reflex? | Grab head of patient gently/firmly – if you shift their head, they are still looking at you. If vestibular sys not working, then eyes go with head and cannot shift back. |
| symptoms of vestibular lesion (3) | vertigo, nystagmus, dysequilbrium |
| symptoms of __________ lesion may produce nystagmus in various directions in the absence of vertigo. | central |
| Which system, central or peripheral, will produce a horizontal nystagmus only in the presence of vertigo? | peripheral |
| nystagmus without vertigo | central |
| nystagmus only when there IS vertigo | peripheral |
| vestibular symptoms such as equilibrium loss, nystagmus, vertigo accompany progressive loss of hearing and tinnitus. Age of onset 20-30 yrs. | Meniere's disease |
| Meniere's symptoms (5) | vertigo, nystagmus, dysequalibrium, progressive hearing loss, tinnitus |
| Is Meniere's central or peripheral? why? | peripheral because nystagmus in presence of vertigo |
| Acoustic neuroma is also called | Schwannoma |
| tumor of the vestibular nerve; slow growing and relatively benign | Schwannoma/acoustic neuroma |
| Where is an acoustic neuroma/Schwannoma typically found? | internal acoustic meatus or cerebellopontine angle |
| What other nerves may an acoustic neuroma/Schwannoma affect besides CN VIII? | V and VII |
| Schwannoma may affect cranial nerves? | V, VII, and VIII because of the exit locations of the nerves in relation to one another |
| We can detect the smell of several hundred thousand odors. What percentage are noxious and what percentage are pleasant? | 80% noxious, 20% pleasant |
| Around what structure is the olfactory epithelium located? | cribriform plate of ethmoid bone |
| 3 main types of olfactory cells | 1-basal, 2-receptor, 3-support |
| There are 3 Olfactory cell brothers (BRS.): | Basal, Receptor, Support |
| stem cells that will become new olfactory cells | Basal (BRS.) |
| bipolar cells whose dendrites bind to odorants and whose unmyelinated axons form the olfactory nerve | Receptor (BRS.) |
| which olfactory brother cell's axons form the olfactory nerve CN I? | Receptor (BRS.) |
| What is the third type of olfactory cell brother besides Basal and Receptor? | Supporting (BRS.) |
| What kind of epithelium lines the respiratory tract? | goblet cells and mucus-secreting gland cells |
| Odorant molecules bind to _______ on olfactory receptor cells. | cilia |
| Odorant molecules bind to cilia on olfactory __________cells. | Receptor (BRS.) |
| which cell type is the stem cell that becomes new olfactory receptor cells? | Basal (BRS.) becomes Receptor and they are Supported by other cells. They are a band of BRS. |
| precursor to Olfactory neuron | Basal cell (BRS.) |
| precursor to Olfactory neuron | Basal |
| Cilia of _________________cells are embedded in the mucus layer, right below the olfactory epithelium. Odorants get stuck in the mucus and bind to the cilia on the dendrites of these cells. | olfactory receptor |
| Describe an olfactory receptor cell | Cilia hanging off end of dendrite like a broom on a handle (handle being dendrite), top of broomstick has olfactory receptor cell body, and off cell body is one of the axons that will form the Olfactory CN I, itself. |
| Where does the receptor potential happen on an olfactory receptor cell? | At the cilia-dendrite junction when the odorants have bonded to the cilia |
| Where do action potentials take place on an olfactory cell? | at the olfactory cell body (summation) |
| Where is the conduction zone of the action potential (50mV) on an Olfactory cell? | In the axon of the Olfactory nerve, CN I, coming off the cell body of the olfactory cell |
| Vestibular sys stands you up to pay attention. It is always through the _______ ear. Eyes always meet the horizon. | inner |
| _________labryinth detects movement at beginning and at end of movement | Static |
| Ampulae is where the ___________ cells live | detector |
| Weber’s is tuning fork. Id side with problem first – conclusion is : ipsilateral __________ loss on right or contralateral ____________ loss on the left | sensorineural, conductive is contralateral loss |
| conductive is __________ loss | contralateral |
| The sound lateralizes to the side with ____________ hearing loss so you hear it louder on that side. | conductive |
| Discrepancy on one side but normal on other is ____________ hearing loss | conductive |
| _________ test actually tells you which kind of hearing loss | Weber's (discerns sensorineural from conductive hearing loss) |
| Usually conductive is lost __________ because due to infection | unilaterally |
| injury of the middle ear, via tympanic membrane, ossicles, infections, autosclerosis, resembles putting finger in ear (plugging sound) | conductive |
| hearing loss – destroy hair cells. Nerve getting no input. Cannot detect vibration via air or bone | sensorineural |
| Conductive or Sensorineural hearing loss is ______________ | irreversible |
| The hair cells in the maculae are embedded in a gelatinous mass, the otolithic membrane which contains ________ crystals | CaCO3 |
| The hair cells in the __________ are embedded in a gelatinous mass, the otolithic membrane which contains CaCO3 crystals | maculae |
| Endolymph has potassium. K+ comes in, polarizes cell, causes____ to be released. | Ca+ |
| Kinocilium- longer on one end, when microvilli bend to the long one the cell _______________. Moves to other side and the cell hyperpolarizes | DEpolarizes |
| __________POTASSIUM channels with Ca+ synapse with dendrites of bipolar cells called Scarpas Ganglion (Vestibular Ganglion) | mechanical |
| Cold water produces nystagmus to the _________ side of irrigation | opposite |
| theory is fluid tension is too high, causing abberrant movement | Meniere's disease |
| Reproduction which produces NYSTAGMUS only is _____.Nystagmus with VERTIGO is _____. | CNS, PNS |
| Olfactory nerves go through the cribriform plate to synapse with (2)? in the olfactory bulb. | mitral and tufted cells |
| mitral and tufted cells are located in the | olfactory bulb |
| what are mitral and tufted cells | what olfactory nerves synapse on in the olfactory bulb |
| Olfactory bulb fibers are _________-order neurons. | 2nd |
| Olfactory bulb fibers proceed in the olfactory tract which then divides into? | medial and lateral olfactory striae |
| medial olfactory stria | goes to opposite bulb through anterior commissure |
| connection between medial olfactory striae | anterior commissure |
| lateral olfactory stria | project to Primary Olfactory Cortex (POC) |
| POC primary olfactory cortex contains (2) | entorhinal and piriform cortex |
| where is the POC (entorhinal and piriform cortices) located? | anterior Parahippocampal gyrus surrounding amygdala |
| The olfactory system is cosidered to be a subsystem of the _________system. | limbic |
| Olfactory receptor cells have what structure on their tops that synapse with ehe 2nd order olfactory neuron that makes up the olfactory tract? | glomerulus |
| relays information to the orbitofrontal olfactory cortex and dorsomedial thalamic nucleus | piriform cortex |
| the ________cortex relays information to the olfactory association cortex and dorsomedial thalamic nucleus. | piriform |
| the only sense that reaches the brain without first going through the thalamus | olfaction |
| 3 olfactory cortical regions | orbito-frontal cortex/olfactory association area, entorhinal cortex, piriform cortex |
| gustation | taste |
| embedded between epithelial cells on surface of tongue are | gustatory sensory/receptor cells |
| 3 gustatory nerves of tongue | VII Facial as Chorda Tympani for anterior 2/3, IX Glossopharyngeal for posterior 1/3, and X Vagus for epiglottis |
| What kind of taste cells send their central axons from their ganglion (VII, IX, and X) to the solitary nucleus? | pseudounipolar |
| Ganglion of VII for taste | geniculate ganglion for chorda tympani (anterior 2/3 of tongue) |
| Ganglion of IX for taste | inferior ganglion (posterior 1/3 of tongue) |
| Ganglion X for taste | inferior-nodose-ganglion (for epiglottis) |
| From cranial nerve ganglion VII: __________, IX:____________ and X:______________, central axons from the pseudounipolar cells are sent to synapse in the SOLITARY NUCLEUS. | VII: geniculate for chorda tympani, IX: inferior ganglion, X: inferior-nodose-ganglion |
| Where are the axons from ganglia of Facial, Glossopharyngeal, and Vagus headed with taste information? | Solitary Nucleus (7.9.10) |
| The secondary afferents from the __________ tract ascend through the brainstem with taste info and synapse with the ventral posteromedial thalamus (VPN) | solitary tract |
| Nerves 7.9.10 to solitary nucleus to solitary tract to? | VPN of thalamus |
| From VPN of thalamus, where do the 3rd order neurons head? | through posterior limb of internal capsule to the primary gustatory cortex |
| The primary Gustatory cortex has 3 locations for it's final 3rd order neuron from the VPN: | 1-inferior postcentral gyrus, 2-OPERCULUM, 3-superior insula |
| On the quiz, what part of the primary gustatory cortex was identified? | Operculum |
| What are the 3 parts of the primary gustatory cortex? | inf. postcentral gyrus, Operculum, superior insula |
| the taste-sensitive structures on the tongue | papillae |
| largest and most posterior papillae on tongue | circumvallate papillae |
| Elongated papillae on tongue | Foliate papillae |
| Relatively large papillae towards back of tongue that are much smaller on sides and tip | Fungiform |
| A taste bud is a cluster of | taste cells (receptor cells), gustatory afferent axons and synapses with taste cells, and basal cells |
| taste/receptor cells, gustatory afferent axons and synapses with taste cells, and basal cells all make up a | taste bud |
| Microvilli at the apical end of taste cells extend into the | taste pore |
| the site where chemicals dissolved in saliva can directly interact with taste cells | taste pore |
| Taste I area | somatosensory cortex |
| Taste II area | insula |
| Name the Taste I and II areas | Somatosensory cortex (I)and Insula (II) |
| At the solitary nucleus level (4th ventricle), what happens to taste afferents from tongue and epiglottis (VII, IX, X)? | Cross Great Sensory Decussation to VPN of contralateral thalamus, synapse, then 3rd order goes to gustatory cortex (inferior postcentral gyrus is the somatosensory cortex taste area I, Operculum, and superior Insula taste area II) |
| salty primary ion entering? direct or 2nd messenger? | Na+ direct to depolarize, Ca+ in to release NT |
| Sour primary ion entering? direct or 2nd messenger? | H+ or H+ block potassium channel direct to depolarize, Ca+ in to release NT |
| Sweet primary ion entering? direct or 2nd messenger? | tastants bind directly to G-protein linked receptors, cAMP block potassium, depolarize, Ca+ in to release NT |
| Bitter primary ion entering? direct or 2nd messenger? | Can either block potassium (bitter 1) or bind to G-protein linked receptor (bitter 2) to IP3, release Ca+ from internal storage site. PIP. |
| Umami/savory primary ion entering? direct or 2nd messenger? | Na+ but is a receptor for amino acids GLUTAMATE or ARGININE to depolarize, then Ca+ in to release NT |
| 2nd messengers are | bittersweet |
| the visual field of each eye is separated into | 4 quadrants (upper, lower, right, left) |
| the quadrants of visual field are also called (right and left) | nasal and temporal |
| The _________receives the visual field projection | RETINA |
| Receives the visual field projection | retina |
| In the retina, the the visual field projection image is | crossed and inverted |
| The Temporal 1/2 of visual field projects in the | nasal 1/2 of the retina |
| Think of the visual field as a rectangle, divided in two with the medial half called the nasal visual field and the lateral half called the temporal visual field. | Now think of the eyeball as divided in half, with the medial half called the nasal retina and the lateral half called the temporal retina. |
| The temporal visual field projects into the ____________ retina. | nasal |
| The nasal visual field projects into the ____________ retina. | temporal |
| Think of the visual field as a rectangle, divided into upper and lower halves. The upper half projects to the Temporal lobe. The lower half projects to the Parietal lobe (just the opposite of what you'd expect) | The upper half of the visual field (temporal lobe) projects to lower retina. The lower half of visual field (parietal lobe) projects to upper retina. |
| The upper half of the visual field projects to the ________half of the retina. | lower |
| The lower half of the visual field projects to the _________half of the retina. | upper |
| Where do optic fibers cross? | optic chiasma |
| In the optic chiasma, fibers will partiall cross so the left half of the visual field enters the | right optic tract, and vice versa |
| Where do the optic tracts synapse? | lateral geniculate body |
| LGB | lateral geniculate body where optic fibers synapse after crossing/decussating in the chiasma. |
| Fibers from the LGB will form the | OPTIC RADIATION |
| The optic radiation fibers from the upper half of visual field will form the | Loop of Meyer in the Temporal Lobe |
| The Loop of Meyer | optic radiation fibers from the upper half of the visual field that project from the LGB into the temporal lobe |
| Relating to visual, the temporal lobe contains | the Loop of Meyer, which are the fibers from the upper half of the visual field |
| Fibers from the LGB forming the optic radiation from the lower half of the visual field will project to the | parietal lobe |
| Lower visual field to | parietal lobe |
| upper visual field to | temporal lobe Loop of Meyer |
| The optic radiation fibers that formed the Loop of Meyer in the temporal lobe will terminate in the | Lingual gyrus (upper part of visual field) which is the lower optic gyrus. |
| The upper visual field | Decussate to contralateral in chiasma, LGB to optic radiation, form Loop of Meyer in temporal lobe, terminate in Lingual gyrus. |
| Optic radiation fibers from the parietal lobe (hence lower visual field) terminate in the | Cuneus |
| The lower visual field | decussate contralateral in chiasma, LGB then optic radiation, through parietal lobe, terminate in Cuneus |
| Cuneus has the __________ visual field projection. | lower |
| Lingual gyrus has the __________visual field projection. | upper. |
| Dust the R optic nerve | R anopsia (complete loss) |
| Dust the optic chiasma | Bitemporal hemianopsia (no peripheral vision) |
| Dust the R optic tract | L homonymous hemianopsia (no left visual field on either eye) |
| Dust the R Lateral Geniculate Body | L homonymous hemianopsia (no left visual field either eye) |
| Dust the R Optic Radiation | L homonymous hemianopsia (no left visual field either eye) |
| pressure on Left optic chiasma due to occluded/enlarged Internal Carotid Artery | ipsilateral (left, in this case) Nasal Hemianopsia if it's one carotid or Bilateral Hemianopsia if it's both carotids |
| What would cause a sagittal lesion to the visual system at the optic chiasm? | Pituitary adenoma |
| lesion to R Loop of Meyer | Left Upper Quadrant Homonymous Hemianopsia ("pie in the sky" temporal lobe lesion means you are always looking up towards contralateral side of lesion) |
| lesion to R temporal lobe | Left Upper Quadrant Homonymous Hemianopsia ("pie in the sky" lesion to temporal lobe/loop of Meyer means you are always looking up to contralateral upper quadrant) |
| lesion to R optic radiation in Parietal lobe | Left Lower Quadrant Homonymous Hemianopsia (the lower half of visual field projects to parietal lobe before ending in in the Cuneus, so a loss to parietal is lower opposite quadrant) |
| lesion to R optic radiation in temporal lobe/Loop of Meyer | Left Upper Quadrant Homonymous Hemianopsia (temporal lobe/loop of Meyer receives from upper visual field, before ending in lingual gyrus. Lesion causes loss of contralateral upper quadrant, commonly known as the "pie in the sky" effect) |
| Optic radiation temporal lobe/loop of Meyer is __________ visual field headed to _________. | upper, Lingual |
| Optic radiation parietal lobe is _________ visual field headed to _______________. | lower, CUNEUS |
| Whenever the primary visual cortex (lingual gyrus/upper field or cuneus/lower field), what is spared? | the macula |
| Lesion entire R primary visual cortex | Left Homonymous Hemianopsia with sparing of the Macula |
| primary visual cortex | Lingula (upper field), Cuneus (lower field) |
| lesion R lingual gyrus | Left upper quadrant homonymous anopsia with sparing of the macula |
| lesion R cuneus | Left lower quadrant homonymous anopsia with sparing of the macula |
| a medical term for a type of partial blindness resulting in a loss of vision in the same visual field of both eyes. | Homonymous Hemianopsia |
| an oval-shaped highly pigmented yellow spot near the center of the retina of the human eye | macula |
| http://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htm (eye muscle lesion) | http://cim.ucdavis.edu/EyeRelease/Interface/TopFrame.htm (cranial nerve lesion to afferent/efferent path) |
| trace light reflex (11) which leads to constriction of pupil | retina-optic nerve-optic tract-superior brachium-pretectal nucleus BILATERAL-Edinger/Westphal nuclei-CNIII Oculomotor-ciliary gang-short ciliary nuclei-ciliaris & sphincter pupillae muscles |
| which reflex causes pupillary constriction? | light reflex (the loop with optic tract and superior brachium, LGB then to eye again) |
| trace accomodation reflex (15) | retina-CNII-optic T.-lateral geniculate nucleus-optic radiation-visual cortex-frontal eye field-corticobulbar tract-pretectal nucleus BILATERALLY-Edinger/Westphal nuclei-CN III.-ciliary ganglion-short ciliary nerves-ciliaris & sphincter pupillae muscles |
| function of accomodation reflex | convergence, thickening of the lens |
| high velocity eye movements that orient the eyes toward the stimulus | saccadic movements |
| saccadic | high velocity orientation of eyes towards stimulus |
| coordinates visual, somatic, and auditory info. when adjusting the head movement towards a stimulus | Superior Colliculus (eye) and Frontal Eye Field |
| Receives information about motion in the visual field | superior colliculus |
| concerned with motion in the visual field and ATTENTIVEness for identification of BROAD outlines | superior colliculus |
| receives information from the primary visual cortex and is concerned with FINE visual discrimination and SACCADIC movement towards complex visual stimulii | Frontal eye field |
| broad outlines of objects, a general id of objects in the visual field | superior colliculus |
| Receives info from cortex and identifies the finer details of specific objects and is responsible for saccadic movements towards it | Frontal eye field |
| white tough wall of the eye | Sclera |
| thin lining over the sclera and inside the eyelids | conjunctiva |
| clear continuation of the sclera over the iris and pupil | cornea |
| composed of muscles which constrict or dilate the pupil | Iris |
| part of the retina which is most sensitive and has the least number of vessels. Responsible for CENTRAL vison. | Macula |
| 2mm pit in the macula where all the retinal layers are shifted away so the image is received by the photoreceptors with the least amt. of distortion. | Fovea |
| a hole in the iris controlled by muscles in the iris. | Pupil |
| The blind spot. Contains no photoreceptors. Passageway of optic nerve and vessels. | Optic disc |
| The macula and fovea are right on the dividing line of the retina between the ___________ retina and the ___________retina. | nasal retina and temporal retina |
| structures on temporal retina side | half of macula, half of fovea |
| structures on nasal side | half of macula, half of retina, Optic disc (blind spot) |
| There are 3 sets of _________ and 2 sets of __________ in the retina. | neurons, interneurons |
| How many sets of neurons in retina? | 3 |
| How many sets of interneurons in retina? | 2 |
| Deepest layer of cells in retina | Photoreceptors |
| Intermediate layer of cells in retina | bipolar cells (get it? They have two poles so they must be in the middle) |
| Superficial layer of cells in retina | ganglion cells |
| What makes up the Optic CNII? | axons of ganglion cells in superficial layer of retina |
| Light has to go through all the layers of the retina to reach the ________________. | photoreceptors |
| 2 kinds of communication cells in retina | Horizontal & Amacrine |
| Cells in retina that allow communication between photoreceptors (deepest) and bipolar (intermediate) cells. | Horizontal cells of retina |
| cells of retina which allow bipolar (intermediate) and ganglion (superficial) cells to chat each other up. | Amacrine (amiable cells) of the retina |
| Why do horizontal cells and amacrine cells of the retina need to facilitate communication between the 3 layers of cells? | Convergence and lateral inhibition |
| lateral inhibition | inhibiting a neighboring cells |
| even though the picture shows the receptor cells as the outer layer, they are considered to be the | deepest |
| high sensitivity to light (1000x) | rods |
| concentrated in fovea | cone |
| saturate in daylight | rods |
| not present in fovea | rods |
| low light sensitivity | cones |
| night vision | rods |
| high acuity | cones |
| not light sensitive | cones |
| day vision/color vison | cones |
| 1 type of photopigment (i.e., see in greyscale) | rods |
| low acuity | rods |
| concentrated in fovea | cones |
| 3 types of photopigment (blue, red, green) | cones |
| single photon detection ability | rods |
| night vision | rods |
| more photopigment, capture more light | rods |
| low photopigment | cones |
| saturate in intense light | cones |
| low acuity | rods |
| high acuity | cones |
| sensitive to light (1000x), single photon detection ability | rods |
| not sensitive to light | cones |
| night vision | rods |
| day vision/color | cones |
| up photopigment to capture more light | rods |
| low photopigment (don't need more light because they see in the daytime) | cones |
| saturate in day light | rods |
| saturate in intense light | cones |
| low acuity | rods |
| high acuity | cones |
| not present in fovea | rods |
| concentrated in fovea | cones |
| 1 type of photopigment | rods |
| 3 types of photopigments (red, blue, green) | cones |
| rods and cones are | photoreceptors |
| 2 types of photoreceptors | rods and cones |
| 2 types of retina | peripheral and central |
| type of retina with MANY photoreceptor cells and MANY ganglion cells | peripheral |
| type of retina with MANY rods | peripheral (remember, rods see at night and in 1 photopigment) |
| type of retina with few cones | peripheral |
| type of retina that is very SENSITIVE to LIGHT | peripheral (rods can detect one photon - you'd want them to be your night vision where there isn't much light) |
| type of retina with many CONES! | central (standard time is daytime!) |
| type of retina with low number of cones and low number of ganglion cells | central |
| type of retina with NO rods. | central |
| Membrane potential of retina in the dark (mV)? | -40mV |
| product continuously produced in photoreceptor to keep sodium channels open and membrane at -40mV (a very low depolarization level, easily overcome - a "high alert" membrane potential) | Cyclic Guanosine Monophosphate |
| CGM | cyclic guanosine monophosphate |
| who makes CGM and where and why? | CGM made by guanylate cyclase in the photoreceptor to keep Na+ channels open |
| light goes through all ________layers | retinal |
| Light goes through all retinal layers and is absorbed by the ______________ epithelium. | pigment |
| Light triggers absorption of the electromagnetic radiation (sun) by the ______________in the membrane of the stacked discs in the photoreceptor's outer segment. | photopigment |
| where does light get absorbed in the pigment epithelium | in the photopigments within the STACKED DISCS lying in the photoreceptor's outer segment |
| where are stacked discs? | in the photoreceptor's outer segment - they contain the pigment of the pigment epithelium that absorbs electromagnetic radiation (sun) after it passes through all retinal layers. Photoreceptors are deepest, remember? |
| photopigment in rods | RhODopsin |
| retinal, a derivative of vitamin A, is bound to an opsin, a 7-pass transmembrane alpha helices receptor protein like G-protein coupled reactions) | RhODopsin, the photopigment in RODs |
| Cones have 3 ________ | opsins |
| Young-Helmholtz trichomacy theory | combination of relative excitation and inhibition of the red, blue and green opsins in the cones accounts for our color vision |
| what accounts for color vision | excitation and inhibition of RGB opsins in the CONES (Young-Helmholtz theory of trichomacy) |
| Light bleaches half of the photopigment molecule in the rods called | retinal (retinal + opsin = RhODopsin) |
| Light bleaches | retinal |
| The bleaching retinal activates ___________, the other half of the RhODopsin molecule. | opsin |
| When light bleaches retinal and this activates opsin, what G-protein is stimulated and where? | Transducin in the stacked disc membrane |
| When light bleaches retinal, stimulates opsin, and activates Transducin in the stacked disc membrane, an effector enzyme called _______ breaks down cGMP. | PDE (PhosphoDiEsterase enzyme) |
| When PDE breaks down cGMP, what happens? | Sodium channels close! and the photoreceptor membrane HYPERPOLARIZES to -70mV. |
| What is the effect of Hyperpolarization of the photoreceptor membrane to -70mV when the Na+ channels snap shut? | Glutamate level DECREASES |
| what neurotransmitter level decreases with hyperpolarization of photoreceptor membrane to -70mV? | glutamate |
| When we go from a lit room to a dark room, the photoreceptor's sensitivity to light increases by _______________x. | 1 million |
| Our pupils dilate when we go into a dark room and unbleached __________ regenerates in the rods via a process that requires Ca+ | RhODopsin |
| When we walk into a dark room, our pupils dilate and unbleach rhodopsin regenerates in the ________ via a process that requires _____. | rods, Ca+ |
| area of the retina that, when stimulated by light, changes the cell's membrane potential. | Receptive field |
| What happens when the Receptive field of the retina is stimulated by light? | The Receptive Field changes the cell's membrane potential. |
| where are bipolar cells? | intermediate layer |
| The receptor field, that can change a cell's membrane potential when stimulated by light, is full of __________ cells. | bipolar |
| There are 2 areas of the REceptor field: | 1. Center 2. Surround |
| photoreceptors that directly synapse with bipolar cells are located in the _________of the Receptor field | CENTER (direct synapse with bipolar) |
| photoreceptors that synapse on horizontal cells which, in turn, synapse on the bipolar cell are located in the _____________of the Receptive field. | surround |
| Direct synapse between bipolar and photoreceptors takes place where? | in the CENTER of the REceptive field |
| indirect synapse by photoreceptor cells first on the horizontal cells, which then synapse on the bipolar cells takes place in the | surround of the Receptive field |
| surround is | indirect via horizontals |
| Center is | direct between photoreceptors and bipolars. |
| The Receptive field centers are _____________. | Antagonistic |
| If the surround Receptive field (indirect) is ON, then the center Receptive field (direct) is _____. | OFF |
| Antagonistic receptor fields | surround and center are never on at same time |
| In either case of surround-ON/center-OFF or vice versa, what are the bipolar cells doing? | depolarizing |
| ON bipolar cell means the cell depolarizes when light is | on |
| When a bipolar cell depolarizes when light is ON, less ____________ released by the photoreceptors. | glutamate |
| Which cell in retina releases glutamate? | photoreceptors |
| What kind of receptors on the ON-bipolar cell causes depolarization? | G-protein coupled GLU receptors |
| what kind of receptor is on the membrane of a bipolar cell for ON (light depolarization)? | G-protein linked Glutamate receptor |
| In an OFF-bipolar depolarization, the cell depolarizes when light is OFF. In this case, more ________ is released by the photoreceptors. | Glutamate |
| What kind of receptor is in the bipolar cell membrane for OFF (dark depolarization)? | glutamate-gated direct ion channels |
| What is the neurotransmitter of the retina? | Glutamate |
| In either ON (light depolarization) or OFF (dark depolarization), what neurotransmitter causes the depolarization of the bipolar cell? | Glutamate |
| Where are ganglion cells in the retinal 3 layers? | most towards surface of retina |
| Like bipolar cells, ganglion cells also have ___________ receptive fields. | Antagonistic |
| Antagonistic receptive fields are found on both | bipolar and ganglion cells. |
| How do ganglion cells react to light? | They "gang up on it" with a barrage of Action Potentials |
| The response to stimulation of the center receptive field of ganglion cells may be canceled by the ? | response of the surround receptive field, hence antagonistic |
| Ganglion cells in our retinas are responsive to differences in ________________ within their receptive fields. | ILLUMINATION within their receptive fields |
| 2 types of Gang members in the retina | M & P (Magnocellular & Parvocellular) |
| Ganglion cell with large receptive fields, responds to MOTION and low contrast stimuli, ergo they aid in LOW RES vision | Magnocellular Ganglion |
| Ganglion cell that has a small receptive field, color opponent cells (sensitive to wavelength). Red-Green-Blue-Yellow. Responsible for COLOR VISION ergo fine detail discrimination. | Parvocellular ganglion |
| cells which detect motion and broad outlines | parietal |
| area in brain where image appears | visual cortex |
| lobe which detects shape, form and color | Temporal |
| cells responsible for forming optic nerve (CNII) | ganglion |
| If Weber's test is performed and there is lateralization, do you still have to perform Rinne's test? | yes, always both |
| where is the superior cerebellar peduncle | in the midbrain |
| responsible for central vision | macula |
| When pupil is introduced to light on either side but neither constrict, what is damaged? | Oculomotor n. CNIII |
| What causes bitemporal hemianopsia? | pituitary adenoma (presses on optic chiasma) |
| lesion to R optic tract | Left homonymous hemianopsia because it has decussated so contralateral |
| describe layers of retina by cell from outermost to deepest | Outermost: ganglion cells that make up CN I Optic nerve. Middle: bipolar cells. Deepest: Photoreceptors |
| Does light have to travel through all the retinal cells layers to get to the photoreceptors? Why? | Yes, because they are deepest. |
| Cells that make the bAg of the retina | b for bipolar, A for Amaracrine, and g for ganglion. This is how you remember the Amaracrine are between the bipolar and the ganglion cells. |
| What cells are between the photoreceptors (deep) and the bipolar (middle)? | Horizontal |
| What makes up the optic nerve | axons of the ganglion cells of the superficial layer of retina |
| cones are | NPT light-sensitive. They are for seeing when the sun is out. |
| cones _____________ in intense light | saturate |
| cones have ___ types of photopigments | 3 (RGB) |
| rods are | very light sensitive. They are for seeing in the dark. If you are walking in the dark, it helps to carry a big rod. |
| rods are used at | night |
| rods only have one type of | photopigment (who needs colors at night?) |
| rods saturate in | plain old daylight. Outta here! They are vampires. Vampire Rod - no bright lights, please. |
| Which do we use for night vision, our peripheral retina or our central retina? Why? | peripheral, because it is heavy on the Vampire Rods and the photoreceptors for even the smallest amt of light detection but it has no cones so it sucks at details. Cones are for outlining the details of life. Vampire Rod is only interested in the night. |
| Cones are for __________ the details of life. | outlining. They are good for detail/discrimination. |
| What structure has lots of cones, no rods? | Central retina |
| The central retina has lots of _________for outlining details. | cones. |
| Does the central retina have any rods? | no, Vampire Rod isn't interested in details. |
| Vampire Rod lives on the periphery, in the peripheral retina, sensitive to the tiniest bit of ligt (lots of photoreceptors) and able to detect the motion of even a single passed out photon from 500 yds. Tell me about him. | Vampire Rod - no details, lives in the peripheral retina, night vision, lots of rods and photoreceptors and ganglion in his world. Saturates/afraid of plain old daylight. 1000x more sensitive to even 1 photon. V.R. is phobic of the fovea. |
| The central retina is like a Disney film, full of color and details and bright light, all marked off carefully by a ring of _______. | cones |
| CCR does not mean creedence clearwater revival; it means: | Central cones retina |
| light waves becoming actual photoreceptor potential (photons to chemical energy) is called | PhotoTRANSDUCTION |
| membrane potential of retina in the dark | -40mV!!!! |
| It is very exciting to Dr. T that the membrane potential of the retina in the dark is | -40mV!!! |
| an enzyme in the photoreceptor cell (deepest layer) continuously keeps the ____ channels open so that the membrane potential may remain at _____!!!!! in the dark. | Na+, -40mV |
| Cyclic guanosine monophosphate is continuously produced by the photoreceptor enzyme ____________________, keeping the sodium channels open (-40mV). | guanylate cyclase |
| how does the photoreceptor keep the membrane potential so low? It does it with a little bit of bat ________. | guano! (keeps Na channels open and membrane p. at -40mV!!!) |
| Name the 3 layers of the retina and the interneurons again, from outermost to deepest: | ganglion are outer, then Amacrine, then bipolar in the middle (bAg), then Horizontal, then deepest are photoreceptors |
| Light goes through all the retinal layers (3) and is absorbed by the | pigment epithelium |
| What absorbs light after it gets through all the layers? | pigment epithelium |
| pigment epithelium? | PE is the layer which convinces the photopigment lying in the stacked discs of the photoreceptor layer to take in the poor wandering electromagentic radiation (light) which traveled all that way. Pigment Epithelium is guilt. |
| What does Pigment Epithelium do? | PE is guilt - it convinces the deepest photoreceptor photopigment to absorb/take in the electromagnetic radiation into the stacked discs. |
| Where are stacked discs and what goes in there? | in the photoreceptors' outer segment. Inside stacked discs live miserly photopigments who, when guilted into it by Pigment Epithelium, will take in/absorb electromagnetic radiation that did, after all, come through all those layers of retina. |
| Where does photopigment live? | in the (highrise) stacked discs of the outer segement of photoreceptors |
| Remember Vampire Rod who sees not very well but has night vision and lives in the peripheral retina? He can detect a single photon of light. In V.R's photoreceptor outer cape, he has only one assistant photopigment in his stacked discs: | Rhodopsin (like Renfield, only smaller- if you don't know who Renfield is, you need to watch a real vampire movie instead of twi-lite) |
| The only personal photopigment assistant Vampire Rod has in his stacked discs? | Rhodopsin |
| What is rhodopsin and where is it? | retinal, a derivative of Vitamin A, is bound to an opsin which is a 7-pass G-protein linked/coupled receptor. Rhodopsin is found in the stacked discs of the outer cape of Vampire Rod the Photoreceptor. It's his only photopigment/assistant for night! |
| Vampire Rod has his assistant Rhodopsin; what do cones have? | 3 opsins and this excitiation of the three (RGB) opsins accounts for our color vision, according to the Y-H trichromacy theory |
| The cones are for outlining details and color in broad daylight (think Disney movie) - what do they have, according to the Young-Helmholtz theory of tricromacy, that allows us to see in technicolor? | 3 opsins (Red, Green, Blue) that get excited or inhibited, accounting for our color vision. |
| The 3 little RGB opsins live in the bright, sunlight, detailed world of Disney _________ photoreceptors. | cones |
| An opsin is a | 7-pass transmembrane alpha helices receptor protein like G-coupled receptors |
| How many opsins live at Disney world cones? | 3 |
| How many opsins live with Vampire Rod? | just one: Rhodopsin which is retinal + opsin |
| Vampire Rod has Rhodopsin in his stacked discs - what happens when PE convinces the photopigment Rhodopsin to take in the electromagnetic energy of light, considering it might be just one little ol' photon having come all that way in the dark? | The light/photon "bleaches" the retinal A, and once that's out of the way, Opsin can get activated! |
| Now that retinal is bleached out of the way (ie, half of the Rhodopsin is gone), the opsin of the Vampire Rod photoreceptor wakes up. What happens next? | Transducin (remember we are following phototransduction cascade) is a G-protein stimulated by opsin waking up. Transducin activates his PDE to break down cGMP (cyclic bat Guano-mono phosphate shit). |
| Retinal bleached. Opsin awake. Calls Transducin. Transducin gets on his ______ and breaks down bat __________. | PDE, cGMP |
| What happens when PDE breaks down bat cGMP? | The sodium channels close and the Photoreceptor (Vampire Rod) membrane HYPERPOLARIZES (shuts the casket lid) and turns down the juice to -70mV. This means less and less glutamate is released. Sleepy time. |
| When cGMP is broken down by PDE, what closes? | SODIUM channels! When Na+ channels close, Vampire Rod's photoreceptor membrane hyperpolarizes to -70mv and V.R. shuts the casket lid - he's not getting any glutamate now. Decrease. Sleep. Hyperpolarize. No salt, no glutamate, no Chinese food. |
| How do ganglion cells, the outermost cells of the retina, react to light? | with a BARRAGE OF ACTION POTENTIALS! |
| The response of ganglion cells in the center may be ___________ by the response of the surround and vice versa. | cancelled/lateral inhibition |
| because the response to stimulation of the center ganglion cells may cancel out the surround ganglion cells, we can say the ganglion cells in our retinas are mainly responsive to differences in ___________ within their receptive fields. | illumination within their receptive fields (in other words, the center cells see light and the peripheral cells see, well, dark, and neither wants to swap jobs) |
| respond to LARGE receptive fields~ | Magnocellular |
| respond to s m a l l receptive fields~ | p a r v o cellular |
| 2 types of ganglion cells | MAGNOcellular & p a r v o cellular |
| large receptive fields, respond to object motion and low contrast stimuli - aid in low contrast vision | MAGNOcellular (these live out in the periphery with Vampire Rod photoreceptor and his sidekick Rhodopsin, casting large nets for a photon here and there in low or night light) |
| Vampire Rod photoreceptor picks up motion in peripheral vision, esp. in low light. What ganglion cell compliments V.R. at night? | MAGNOcellular ganglion (wide net casting for sometimes single photon to pounce on) |
| ganglion with a small receptive field, color opponent cells that are sensitive to wavelength, RGB+Yellow! so responsible for color vision, Disney style! Discrimination of fine detail, color, bright lights baby! | p a r v o cellular ganglion (in conjunction with Disney cones that live in the center of the retina and illuminate the world!) |
| LGN | lateral geniculate nucleus |
| how many layers of LGN are there? | 6 going from back to front |
| how are the 6 layers of the LGN numbered? | back to front |
| Which LGN layers contain MAGNOcelluar ganglion (the wide nets for object motion and low contrast stimuli at night)? | 1,2 layers contain M-type (MAGNO) cells and receive synapses from M-ganglion cells |
| cells furthest in back of LGN | MAGNO for night vision and motion detection (M-type cells and M-type ganglion) |
| Layers 2-6 of LGN contain what type of cells? | p a r v o -type (P-type cells receiving synapses from P-type ganglion) |
| LGN magnos are found where? | layers 1,2 (all the rest are p a r v o) |
| LGN layers that receive fibers from ipsilateral retina | 2.3.5 |
| It's 2:35pm - what side of your LGN is getting a call from the retina? | The same side! (layers 2.3.5) |
| if the ipsilateral side of retina sends fibers to LGN layers 2.3.5, obviously the contralateral retina sends fibers to LGN layers _________ | 1-4-6 |
| If the brain is a tonotopic reflection of the body, and the LGN has 6 layers, how many layers does the primary visual cortex have? | 6 |
| area 17 | striae cortex/primary visual cortex |
| the Primary Visual Cortex (PVC -hahahaha!) is found in Area ____ at Lowe's home store. | 17 |
| What aisle is the PVC in at Lowe's home store? | aisle 17 has PVC |
| There are 6 ________________layers of PVC/area 17 | histological |
| Where do areas I and II of visual cortex get their info? | LGB, ja rule! |
| Where does area III get its info? | III is P! III is P! and it goes everywhere if you P in the pool. (all other cortical layers) |
| From what cells does area IV get its information? | M & P from the LGB, word. |
| Area V is a Superman jive - he can ___________ you wit' a look from his eye. | pulverize (pulvinar and superior colliculus to V) |
| Like I and II, VI is straight LGB, fool! Don't f*** with Santa __________. | Claus(trum) |
| I & II from LGB. III got P going everywhere, see? Yo! IV-abc get M&P from the LGB, word. Area V is da Superman jive - he can pulverize you wit a look from his eye. Like I & II, VI is straight LGB, fool! Don't f*** with Santa Claus. Uh.haha!Uh. | I & II: LGB, III: P to all cortical areas, IV-abc: M&P from LGB, V: Superior colliculus + pulvinar, VI: LGB + Claustrum |
| Layer IVc is organized into alternating ocular __________ _____________ | dominance columns |
| LGB fibers from one side (ipsi) of the retina are going to end up in the __________ next to the lateral geniculate body fibers from the contralateral retina. | Primary Visual Cortex (PVC) |
| LGB fibers from the same side (ipsilateral) retina are going to end up in the primary visual cortex next to the LGB fibers from the __________ retina. | contralateral |
| The PVC (yes, plumbing pipes) receives the ___-type cells and streams the channel through V2 (area 18 & 19) to the parietal cortex for analysis of motion. | M |
| Where does the PVC shuttle M cell channels? Why? | PARIETAL cortex for Motion analysis (M for Motion analysis) |
| Motion analysis is done in the __________ cortex via the ___-cells. | Parietal, M-cells (remember Magnocellular are associated with Vampire Rod in the Periphery an see in the dark to detect a rat moving, in case V.Rod wants to eat it) |
| Oh no, Interblobs!!!! agghhhhhhh!!!!!! | shape |
| and baby Blobs! agghhhhh!!!!! | color |
| The primary visual cortex separates ___ -type cell information (detail Disney bright as day parvocellular stuff) into two basic Disney creatures: | Interblobs and Blobs! |
| The Disney monster Interblob detects | shape |
| The Disney creature Blob likes | color |
| The PVC separates P-cell (parvo Disney bright acuity detail) info into shape and color. What monsters receive shape? color? | shape is Interblob! color blobs. |
| The P-type (parvo detail) information is separated in the primary visual cortex. What happens then? | Shape ends at an Interblob! while color stops in a Blob. These 2 channels are streamed through V2 to the TEMPORAL cortex for shape & color perception and visual memory. |
| Parietal gets M-cell Motion, Temporal gets P-cell shape and color. What else does temporal get via the Blob and Interblob guys? | visual memory |
| Shape, color, visual memory - where? | temporal lobe via P-cell (bright detail Disney) |
| I can't make this stuff up: where does color end in the temporal lobe? | in a Blob. |
| I can't make this stuff up: where does shape end in the temporal lobe? | with an Interblob! aggghhh!!!! |
| Where does visual memory get processed? | Temporal lobe with shape and color (Interblob and Blob) via P-cell |
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