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130 Cards in this Set
- Front
- Back
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what type of neurons are olfactory?
what's on distal end? |
bipolar
distal ends are enlarged as olfactory vesicles with cillia |
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How many odorant receptors are in the cilia?
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1000, responds to dissolved substances
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How many primary odors exist?
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7 (maybe 50)
1. camphorous 2. musky 3. floral 4. peppermint 5. etheral 6. pungent 7. putrid |
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What are 2 characteristics of olfactory thresholds?
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low threshold
quick accomodation |
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Describe an olfactory neuronal pathway
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1. axons of the olfacotry neurons in the olfactory epithelium project through foramina in the cribiform plate to the olfactory bulb
2. axon of olfactory bulb go thru olfacotry tract to olfactory cortex 3. lateral olfactory area does conscious perception of smell 4. medial olfactory area does visceral and emotional response to odors 5. intermediate olfactory area receives input from medial and lateral 6. intermediate axons go along ollfactory tract to olfactory bulb |
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Name the different types of taste buds.
which papillae don't have taste buds? |
circumvallate
fungiform folliate Filiform papillae don't have taste buds |
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What is the most sensitive taste bud?
Which are largest but least numerous? |
folliate most sensitive
vallate are largest and least numerous |
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What are the 5 primary tastes?
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salt--Na diffuse thru gustatory hairs
sour --acids sweet --g protein mechanism bitter--g protein mechanism umami--amino acids bind to receptors |
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what are the neuronal pathways for taste?
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1. axons of sensory neurons pass thru cranial nerves VII, IX, X and thru ganglion
2. axons enter the brainstem and synapse in the nucleus of tractus solitarius 3. axons from tractus solitarius synapse in the thalamus 4. axons go from thalamus to taste area of corte |
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What are 5 accessory structures of the visual system?
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1. eyebrows (shade and keep sweat out)
2. eyelids (protect, lubricate) 3. conjunctiva (cover) 4. lacrimal glands (produce tears) 5. extrinsic eye muscles (movement) |
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What does the fibrous layer of the eye consist of?
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sclera --white connective tissue
maintains the shape / muscle attachment cornea--refracts light |
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What does the vascular layer of the eye consist of ?
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iris--ANS/controls amount of light
ciliary muscles--control shape of lens produces aqueous humor |
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What does the retina contain?
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neurons sensitive to light
macula (fovea centralis) greatest visual acuity optic disc--nerves exit and blood vessels enter eye (blind spot) |
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What are the 3 chambers of the eyeball?
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anterior--aqueous humor
posterior--aqueous humor vitreus--vitreous humor |
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What holds the lens in place?
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suspensory ligaments attached to ciliary hairs
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What structures in the eye refract light?
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cornea--most of the convergence
aqueous humor lens--adjusts focal point by changing shape vitreous humor |
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How does the lens change shape?
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ciliary muscles relax=flattens
(emmetropic eye) ciliary muscles contract= more spherical focus on objects less than 20 feet away (accomodation) |
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What is the far point of vision?
near point? |
distance at which the eye no longer has to change shape to focus on an object
near point is closest an object can come to eye and still be focused |
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What happens to pupil during accomodation?
Why? |
pupil becomes smaller
increases the depth of focus |
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What is the pigmented layer of the eye and what does it do?
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contains melanin
works with choroid to create black backdrop enhances visual acuity |
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What are Rods responsible for?
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vision in low illumination
rhodopsin split by light into retinal and opsin=hyperpolarization light adaption=reduction of rhodopsin dark adaption=increase in rhodopsin |
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What are cones responsible for?
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color vision and visual acuity
3 types most sensitive to red, blue and green perception of color is a mixture of different types of cones active at that moment |
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Where is there a high concentration of cones?
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fovea centralis
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What do rods and cones synapse with?
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bipolar cells which synapse with ganglion cells which form optic nerves
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What is the neuronal pathway for vision?
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1. visual field divided into nasal and temporal parts
2. light passes thru lens and from each half projects ot opposite side of retina 3. optic nerve consists of axons extending from retina to optic chiasm 4. axons in optic chiasm from nasal part cross and project on opposite side. axons from temporal part of retina do not cross 5. optic tract consists of axons that have passed thru the optic chiasm to thalamus 6. axons synapse in lateral geniculate nuclei of thalamus and collateral branches go to colliculi (superior) 7. optic radiation has axons from thalamic neurons that project to visual cortex 8. right parts of visual field project to the left side of brain left part of each visual field projects to right side of brain |
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What is depth perception?
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the ability to judge relative distances
comes from binocular vision (slightly different image is seen from each eye) |
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What is the osseous labyrinth?
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canal system within the temporal bone
contains perilymp and membranous labryinth |
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Where is the endolymph
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inside membranous labryinth
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what are the structures of the external ear?
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auricle
external acoustic meatus |
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Describe the middle ear
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middle ear connects the external and inner ears
tympanic embrane (stretched over external acoustic meatus) malleus, incus and stapes connect the tympanic membrane to oval window of inner ear auditory tube connects the middle ear to pharynx and equalizes pressure |
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What are the three parts of the inner ear?
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semicircular canals
vestible (utricle and saccule) cochlea |
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What is the cochlea?
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spiral shaped canal within the temporal bone
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Describe the 3 compartments of the cochlea
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scala vestibuli and scala tympani contain perilymph
cochelar duct contains endolymph and organ of Corti |
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What is the spiral organ (organ of Corti)?
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consists of inner and outer hair cells that attach to the tectorial membrane
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What is perilymph?
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fluid contained within the bony labyrinth of the inner ear
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What is endolymph?
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Fluid found within the membranous labyrinth of the inner ear.
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Describe auditory function
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1 auricle funnels sound waves down external acoustic meatus causing tympanic membrane to vibrate
2. vibrations carried along ossicles to oval window in inner ear 3. stapes moves causes perilymph, vestibular membrane, endolymph to basilar membrane to vibrate 4. stereocilia bend on inner hair cells of spiral organ 5. K+ channels open 6. depolarization 7. glutamate released and stimulates vestibulocochlear nerve |
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What is the olivary nucleus?
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synapse with VIII here and efferent neurons project back to the cochlea where they regulate the perception of pitch
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What is the neuronal pathway for hearing?
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1. sensory axons from the cochlear ganglion terminate in the cochlear nucleus in the brainstem
2. axons from the neurons in the cochlear nucleus project to the superior olivary nucleus or to the inferior colliculus 3. Axons from the inferior colliculus project to the medial geniculate nucleus of the thalamus 4. Thalamic neurons project to the auditory cortex 5. neurons in superior olivary nucleus send axons to the inferior colliculus back to the inner ear or to the motor nuclei in brainstem that send efferent fibers to the middle ear muscles (dampens sound in middle ear) |
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What is static balace?
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evaluates the position of the head relative to gravity and detects linear acceleration and deceleration.
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What do the utricle and saccule contain?
What is it? |
maculae
consists of hair cells with the hairs embedded in a gelatinous mass that contain otoliths |
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What does the gelatinous mass do?
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moves in response to gravity
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What is kinetic balance?
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evaluates movements of the head
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What and where is the crista ampullaris?
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what--hair cells in gelatinous mass (cupula)
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What happens to the endolymph within the semicircular canal when the head moves?
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it moves the cupula
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describe the neuronal pathway for balance
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axons from the maculae and cristae ampullares extend to the vestibular nucleus of the medulla
fibers run from medulla to spinal cord, cerebellum, cortex and nuclei that control extrinsic eye muscles |
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What else does balance depend on?
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proprioception
visual input |
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What are the effects of aging on special senses?
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decline in function for all special senses
loss of appetite visual impairment disorientation risk of falling |
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The lens normally focuses light onto the _________
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macula
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What is aqueous humor?
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watery solution that fills the anterior and posterior eye
exits thru the sleral venous sinus |
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Where are olfactory neurons?
Where do they synapse with mitral or tufted cells? |
pass thru cribiform plate
olfactory bulb |
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Name 3 characteristics of olfactory cells?
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axons combine to form olfactory neurons
olfactory neurons synapse with cells in olfactory bulb olfactory neurons have receptors that react with odorants dissolved in fluid |
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What is the lateral olfactory area do?
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conscious perception of smell
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What does the medial olfactory area do?
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visceral and emotional responses to odor
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What does intermediate olfactory area do?
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connects neurons in the bulb so it modulates sensory info in the bulb
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If limbic system is "emotional brain" which system of olfactory areas is associated with it?
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medial olfactory area
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What are the cranial nerves that detect taste?
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VII (facial), IX (glossopharengeal),
X Vagus |
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What's the taste area of cortex?
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postcentral gyrus
(somatosensory) |
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Describe the relationship between smell and taste
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olfactory sensations porvide inof about a substance that may be thought of as taste.
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Trochlear nerves moves which eye muscle?
What about the Abducent? |
superior oblique
lateral rectus |
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What are the 3 layers of the eye?
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fibrous--sclera and cornea
vascular--choroid, cilliary body and iris nervous--retina |
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What are the whites of the eyes?
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sclera
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What are conjuctiva?
What two types are there? |
thin transparent mucuous membrane
2 kinds: palpebral--inner surface of eyelids bulbar--anterior white surface of eye |
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What is the choroid of the eye?
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connects vascular layer to sclera
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What is retina?
What does it consist of? |
Inner layer
pigmented layer neural layer |
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What allows light rays into interior of eye and bends or refracts it?
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cornea
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What secretes aqueous humor and where is it reabsorbed?
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ciliary process
canal of Schlemm |
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What is glaucoma?
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increased intraocular pressure by build up of aqueous humor.
blockage or overproduction pressure closes off blood vessels, causing starvation and death of retinal cells |
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What is a sty?
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inflammed ciliary gland (modified sweat gland)
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What gland produces tears and where do they go after washing across the eye?
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lacrimal gland
nasolacrimal ducts |
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what are the functions of the sclera?
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attachment points for muscles that move the eye
maintain shape of eye protect internal eye structures |
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What are the 3 main cell layers of the retina?
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Photoreceptors
bipolar cells ganglion cells |
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What is a cataract?
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clouding of the lens resulting from buildup of proteins
occurs from loss of nutrition from aqueous humor occurs as a result of age, infection trauma |
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What is macular degeneration?
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loss of acute vision
older, infections, trauma or hereditary disorders |
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Name 3 characteristics of the cornea
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transparent
refracts light avascular |
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What are 3 characteristics of the cornea
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transparent
refracts light avascular |
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What are 3 characteristics of lens?
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biconvex
helps focus light on retina covered by highly elastic, transparent capsule |
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Where do blood vessels go in eye?
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optic disc
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What are the 3 compartments of the eye?
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anterior--aqueous humor
posterior--aqueous humor vitreous--largest, vitreous humor |
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What does vitreous humor do?
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helps maintain intraocular pressure
shape of eyeball hold lens and retina in place refraction of light |
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What are cilliary processes?
What do they produce? |
complex of capillaries and cuboidal epithelium that produce aqueous humor
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What function do suspensory ligaments perform?
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hold the lens in place
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What do the ciliary muscles do?
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change the shape (thickening) of the lens
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how does the lens become thicker?
how does the lens become flatter? |
cilliary muscles contract
suspensory ligaments relax lens thickens cilliary muscles relax suspensory ligaments pull lens flattens |
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What is myopia?
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nearsightedness
poor distance vision eye is too oval |
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what is presbyopia?
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degeneration of eye due to aging
lens is less flexible reading glasses |
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What is astigmatism?
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refractive error affecting quality of focus
regular (fixed with glasses) and irregular (difficult to fix with glasses) |
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What is hyperopia?
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farsightedness
cornea and lens don't work well together and image is focused behind the retina |
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Describe the Rhodopsin cycle response to light
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1. retinal attaches to opsin to make rhodopsin.
Na+ channels stay open 2. light changes retinal to trans-retinal (opsin changes shape) closes Na+ channels depolarization 3.trans-retianl detaches from opsin 4. Na+ channels open 5.ATP needed to make retinal out of trans-retinal 6. repeat |
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Where is rhodopsin located?
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Rods
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Name 3 characteristics of Rods?
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black and white images
contain rhodopsin general outlines of objects |
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Name 3 characteristics of Cones?
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color images
less sensitive to light than rods sharp clear images |
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what is the main function of the constriction of the pupil?
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affects the depth of focus
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What retinal cells create action potentials?
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ganglion cells
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describe rod cell unstimulated
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1. Na+ channels open, Na+ diffuse into rod cell
2. glutamate is constantly released from unstimulated rod cell 3. glutamate inhibits bipolar cells so that ganglionic cells do not create action potentials |
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Describe rod cell stimulated
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1. rhodopsin activated causes all the gprotein stuff
closes Na+ channels hyperpolarization 2. glutamate released from stimulated rod cells decreases 3. bipolar cells release neurotransmitters which stimulate ganglionic cells to make action potentials |
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What 2 structures regulate the amount of light in the eye?
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iris
eyelid |
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What wavelengths can humans percieve?
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400-700nm
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Name 3 things that bring an image into focus
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accomodation of the lens
constriction of the pupil convergence of the eyes |
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What exits the eye thru the optic nerve?
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axons of ganglion
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Which auditory ossicle is attached to the tympanic membrane?
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malleus
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What does the stapes do?
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causes the oval window to move in and out setting the fluid in the ear in motion
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What is located on the basilar membrane
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receptor cells for hearing
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What is the passageway between the middle ear and the pharynx?
What does it do? |
eustachian tube
equalizes air pressure between the outside air and the middle ear cavity |
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What is perilymph?
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Similar to CSF
located between the membranous and bony labyrinths |
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What is endolymph?
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Similar to CSF
located in the membranous labyrinth |
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What is the organ of corti?
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spiral organ
highly modified cochlear duct cells have hair cells for hearing and regulating basilar membrane tension |
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What is the helicotrema?
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hole at the end of the spiral
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What communicates with the helicotrema?
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scala vestibuli via fluid in the scala tympani
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What are the 2 organs for balance?
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static labyrinth
--utricle --saccule evaluating position of head relative to gravity kinetic labyrinth --semicircular canals evaluates movement of the head |
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What are the orientations of maculae?
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utricle parallels the base of the skull
saccule perpindicular to base of skull |
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What is the kinetic labyrinth consist of?
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3 semicircular canals placed at nearly right angles to eachother
allows you to detect movement in all directions |
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What is an ampulla?
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expanded base of semicircular canal of the kinetic labryinth
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Define crista ampullaris
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specialized epithelium within each ampulla
functions similar to epithelium of maculae |
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Describe what happens in maculae and crista ampullarae
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hair cells are embedded in a gelatinous mass of proteins and calcium carbonate (otoliths)
gelatinous mass moves in response to gravity bending hair cells and initiating action potentials |
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How often are olfactory neurons replaced?
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Every 2 months
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What are canthi?
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angles where eyelids join at the medial and lateral margins of the eye
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Follow a tear from start to finish. What structures does it pass?
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Lacrimal gland
lacrimal duct across the eye past the puncta through the lacrimal canaliculi nasolacrimal canal |
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What do you think about when you hear 'eye muscle innervated by sympathetic fibers'
and 'parasympathetic' |
Dilator pupillae
sphincter pupillae (intrinsic eye muscles) |
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What electromagnetic energy has the longest wavelength?
of colors which one has the longest wavelength? the shortest? |
infared
red blue |
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What is refraction?
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light traveling from one transparent medium to another
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What is emmetropia?
WHen does it occur? |
condition in which lens is flattened so that nearly parallel rays from a distant object are focused on the retina
normal resting condition of lens occurs when viewing objects 20 feet or more from the eye |
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What happens when ciliary muscles contract?
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The choroid is pulled toward the lens
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What type of cells are cones and rods?
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bipolar
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What is accomodation?
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eye focusing on nearby object
parasympathetic stimulation of oculomotor nerve contracts ciliary muscles pull the choroid toward the lens making lens more spherical |
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after light strikes the retina what structures does it go thru?
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photoreceptor
bipolar cells ganglion cells optic disc optic nerve |
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Temporal retina axons go__________
Nasal retina axons go___________ |
same side of brain
opposite side of the brain |
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When the stapes vibrates follow the movement...
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oval window
scala vestibuli helicotrema scala tympani round window |
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What is most important to hearing?
Describe what happens here |
distortion of basilar membrane.
hair cells resting on basilar membrane move relative to the stationary tectorial membrane. causes depolarization (K+) |
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what are some effects of aging on special senses?
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decreased sense of taste
decreased flexibility of lens decreased # of cone cells decreased # of hairs in the cochlea |
