Term
| Name a few characteristics of free nerve endings |
|
Definition
| minimal specialization; C & Adelta axons; transmit pain, temperature and touch; are slowly adapting; have a high threshold of activation |
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|
Term
| Name a few characteristics of Meissner's corpuscles |
|
Definition
| Encapsulated between dermal papillae; project to ABeta axons; located in glaborous skin; pressure sensitive; rapidly adapt; low threshold of activation |
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|
Term
| Name a few characteristics of Pacinian corpuscles |
|
Definition
| Encapsulated onion like covering; project to Abeta axons; found in subcutaneous tissue; detect deep pressure and vibration; rapidly adapting;low threshold of activation |
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Term
| Name a few characteristics of Merkel's disks |
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Definition
| Encapsulated and associated with peptide releasing cells; project to Abeta axons; located in all skin, hair follicles; touch sensitive; slowly adapting; low threshold of activation |
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Term
| Name a few characteristics of Ruffini's corpuscles |
|
Definition
| Encapsulated and oriented along stretch lines; project to Abeta axons; found in all skin; detect stretching ; slowly adapting; low threshold of activation |
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Term
| Name a few characteristics of Muscle spindles |
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Definition
| Associated with Ia and II axons; found in muscles; detect muscle length; can be either rapid or slowly adapting; low threshold of activation |
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|
Term
| Name a few characteristics of Golgi tendon organs |
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Definition
| Detect muscle tension; project to Ib axons; located in tendons; slowly adapting; low threshold of activation |
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Term
|
Definition
| when two nerves receving a stimulus terminate on one first order neuron |
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|
Term
|
Definition
| when one primary sensory neuron terminates on two first order neurons |
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|
Term
|
Definition
| when a nerve inhibits the nerve it was innervated by |
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|
Term
| what is the cascade of action in the visual system? |
|
Definition
| Photons- Rhodopsin-Transducin-phosphodiesterase-cGMP-cationic inward ion channel- channel closes- ca2+ - synapses |
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|
Term
| What is the cascade of action in olfaction |
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Definition
| molecules- olfactory membrane receptors- G protein, adenaylate cyclase III- cAMP and ip3- cationic and anionic inward channels- open channel- ca2+ and protein kinases- impulses |
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|
Term
| what is the cascade of action in Mechanoreception |
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Definition
| displacemsnt- cationic inward ion channels open - myosin/actin motor - synapses |
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Term
| Pain fibers project from primary sensory neurons to where |
|
Definition
| Ipsilatteral dorsal horn neurons |
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|
Term
| Dorsal horn pain neurons project to where |
|
Definition
| Contralateral raphe nuclei and thalamus |
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|
Term
| Raphe nuclei pain nerons project to where |
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Definition
| Periaqueductal gray matter contrallaterally |
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|
Term
| Periaqueductal gray matter pain neurons project to where? |
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Definition
| the hypothalamus and somatosensory cortex |
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|
Term
| where is the Periaqueductal gray located? |
|
Definition
| Next to the cerebral aqueduct in the midbrain |
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|
Term
| where is the raphe nuclei located? |
|
Definition
| The ventromedial area of the mid medulla |
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|
Term
| how do thermoreceptors and nociceptors differ in their threshold and adaptation to heat stimuli? |
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Definition
| Thermoreceptors begin firing at a lower threshold and become saturated before nociceptors begin to fire. Nociceptors have a high threshold but have an even higher level of saturation. |
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|
Term
| How do Adelta and C pain fibers differ |
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Definition
| Adelta pain fibers are myelinated and provide the initial sharp response to pain. C fibers are unmyelinated and provide the slower burning sensations |
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Term
| name some endogenous opioids |
|
Definition
leucine-enkephalin
methionine- enkephalin
beta-endorphin
alpha- neoendorphin
dynorphins |
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|
Term
|
Definition
| referred pain is when visceral tissue pain is presented as pain on the surface of the body, sometimes not near the area of visceral tissue eg. left arm pain from heart attack |
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Term
| how does the body cause pain in injured areas? |
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Definition
| injury or tissue damage releases bradykinin and prostaglandins which sensitize and activate nociceptors. activation of nociceptors releases substance p. substance p acts on mast cells which releases histamine which excites nociceptors. |
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Term
| what areas of the body are most sensitive to two point discrimination? |
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Definition
| fingers, cheeks, nose lips, and toes. think of the sensory homunculus. |
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|
Term
|
Definition
| hyperalgesia is the increased sensitivity to pain |
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|
Term
| what are the optimal firing ranges in Celcius for cold receptors |
|
Definition
|
|
Term
| what are the optimal firing ranges for warm receptors |
|
Definition
|
|
Term
| what is the difference between the optic nerve and the optic tract |
|
Definition
| the optic nerve contains information from only one eye and is the path from eye to optic chiasm. the optic tract contains information from both eyes and goes from optic chiasm to striate cortex |
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|
Term
| at what vibration frequencies would Pacinian corpuscle be activated |
|
Definition
| 50-400 hz, but focused around 200 |
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|
Term
| Describe the four major mechanoreceptors by receptive field size and fast or slow adapting |
|
Definition
Meissner corpuscle small field and fast
pacinian corpuscle large field and fast
Merkel cell small field and slow
Ruffini ending large field and slow |
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|
Term
| what are the benefits of repeating substructures in the mamalian brain |
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Definition
| sometimes they correspond to functional groups, such as in a1. other times we dont know yet. |
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Term
| beginning from outside the eye and including optic structures, explain how light information enters the optic nerve |
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Definition
| light passes through the cornea, the anterior chamber, then the lens, then the vitreous humor, then passes through the retina and contacts photoreceptors. photoreceptors transmit information through bipolar cells to retinal ganglion cells and then to the optic nerve |
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|
Term
| what are the wavelengths that our rods and cones are most suited for |
|
Definition
short cone- 375-475
rod- 400-580
middle cone- 430-625
long cone- 460-650 |
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|
Term
|
Definition
| the area between the absolute threshold and the cones thresholds |
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|
Term
|
Definition
| the area between the cones threshold and rod saturation area |
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|
Term
|
Definition
| the area where only cones are active up till maximum cone saturation/damage |
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|
Term
| what is the function of the ciliary muscle |
|
Definition
| pulls on zonule fibers to adjust the thickness of the lens |
|
|
Term
|
Definition
| nearsideness or a lengthening of the eye |
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|
Term
|
Definition
| farsidedness or a shortening of the ey |
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|
Term
|
Definition
|
|
Term
| why do old people become farsighted? |
|
Definition
| as the lens ages, it becomes less elastic. this increases the minimum focal distance that can be achieved. |
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|
Term
| what happens to the eye shape without visual stimuli |
|
Definition
|
|
Term
| what are the layers of the retina? |
|
Definition
nerve fiber layer
ganglion cell layer
inner plexiform layer
inner nuclear layer
outer plexiform layer
outer nuclear layer
photo receptor outer segments
pigment epithelium |
|
|
Term
| what cell types are found in the inner plexiform layer |
|
Definition
| amacrine cells, and the axons and dendrites of bipolar and ganglion cells |
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|
Term
| what cell types are found in the inner nuclear layer |
|
Definition
| amacrine cell bodies, bipolar cells and horizontal cell bodies |
|
|
Term
| what cell types are found in the outer plexiform layer |
|
Definition
| dendrites and axons of the horizontal, bipolar, rod, and cone cells |
|
|
Term
| what cell types are found in the outer nuclear layer |
|
Definition
|
|
Term
| where are cone cells most heavily concentrated? |
|
Definition
| 0* off center at the foeva |
|
|
Term
| where are rod cells most heavily concentrated? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| what role does retinal play in the visual system? |
|
Definition
| all trans retinal is a component of rhodopsin membrane proteins. All trans retinal is metabolized into 11-cis-retinal. light isomerizes this back to all trans retinal. the eye regenerates this back to 11-cis-retinal in the course of several minutes. |
|
|
Term
| what role does cGMP play in the visual system? |
|
Definition
| cGMP gated channels close in the presence of light, hyperpolarizing the cell |
|
|
Term
| how do cone cells respond to varying intensities of light? |
|
Definition
| the brighter the light flash, the longer and more intense the membrane depolarization. |
|
|
Term
| why is it necessary to have more than one type of cell sensitive to different wavelengths? |
|
Definition
| with only one cell type, while differentiation of various wavelengths might be possible due to changing of average firing rate as the wavelength moved away from the best frequency, frequencies equidistant from the BF in opposite directions would appear identical. |
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|
Term
| which layers of the Lateral geniculate nucleus are considered the magnocellular layers |
|
Definition
|
|
Term
| which layers of the lateral geniculate nucleus are considered the parvocellular layers? |
|
Definition
|
|
Term
|
Definition
| the optic chiasm is the place where visual information deccusates |
|
|
Term
| besides visual cortex, what structures process visual information? |
|
Definition
hypothalamus- for regulation of circadian rhythms
pretectum- for reflex control of pupil and lens
superior colliculus- for orienting movements of head and eyes
Lateral geniculate nucleus- for visual information processing |
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|
Term
| are fibers representing the inferior visual field located superior or inferior to those representing the superior visual field? |
|
Definition
|
|
Term
| What visual deficit would result from a lesion at the right optic nerve? |
|
Definition
| Right monocular blindness |
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|
Term
| What visual deficit would result from a lesion at the optic chiasm |
|
Definition
| loss of peripheral vision |
|
|
Term
| What visual deficit would result from a lesion at the right optic tract? |
|
Definition
|
|
Term
| What visual deficit would result from a lesion at the right superior optic fibers? |
|
Definition
| lower left quadrispatial neglect |
|
|
Term
| why was that cat so happy? |
|
Definition
| cause they had it hooked up to a feeding tube and it just had to look at lights all day. |
|
|
Term
| If an electrode is pushed vertically through the layers of striate cortex, what activation would be expected at each layer? |
|
Definition
| layers 1-3,5,6 would show activation for whatever orientation they were specialized for. layer 4 would not show orientation specificity. |
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|
Term
| if an election is placed horizontally through layers 1,2 or 3 in the striate cortex, what activation patterns would be expected? |
|
Definition
| as the electrode passes horizontally, the orientation specificity would change in a gradient. |
|
|
Term
| where does the information from both eyes first get processed together? |
|
Definition
| the striate cortex, as information is kept separate in the lateral geniculate nucleus. |
|
|
Term
| how is ocular dominance organized in the striate cortex? |
|
Definition
| neurons vary in their ocular dominance columns. |
|
|
Term
| what are some properties of x retinal ganglion cells? |
|
Definition
| medium size; many, most near foeva; medium conduction speed; project to lgn; linear spatial summation; movement sensitive, but not direction sensitive. color coded |
|
|
Term
| what are some properties of y retinal ganglion cells? |
|
Definition
| large cell size; few, most in periphery; fast conduction rate; project to superior colliculus and lgn; nonlinear spatial summation; very movement sensitive but not directionally sensitive; not color coded |
|
|
Term
| what are some properties of w retinal ganglion cells? |
|
Definition
| Vary in size; few in retina; vary in conduction rate; project to lgn and superior colliculus; mixed spatial summation. can be movement sensitive and directionally sensitive |
|
|
Term
| what is processed in the dorsal vision pathway? |
|
Definition
|
|
Term
| what is processed in the ventral vision pathway? |
|
Definition
|
|
Term
| describe the longest pathway visual information could take through the visual cortex |
|
Definition
eye-
dorsal lgn
striate v1
v2
v3
v3a
v4
v5
to one of the streams |
|
|
Term
| what are some properties of simple striatal cortex cells as described by hubel and wiesel |
|
Definition
| respond to edges bars and slits all with preferred orientation of movement; dependent on location in receptive field |
|
|
Term
| what are some properties of complex striatal cortex cells as described by hubel and wiesel |
|
Definition
| respond to edges bars and slits all with prefered orientation of movement; independent of location within receptive field |
|
|
Term
| what are some properties of lower order hypercomplex striatal cortex cells as described by hubel and wiesel |
|
Definition
| respond to edges corners and angles of particular sizes; stimulus orientation and location dependant |
|
|
Term
| what are some properties of upper order hypercomplex striatal cortex cells as described by hubel and wiesel |
|
Definition
| respond to edges corners and angles of particular sizes; similar to lower order hypercomplex cells, but responded at two angles 90 degrees apart |
|
|
Term
| describe the anatomy of the human ear from the outside in. |
|
Definition
| the pinna is the external structure, the concha is the entrance to the external auditory meatus or ear canal. then sound hits the tympanic membrane which vibrates three bones called the malleus the incus and the stapes. these vibrate the basalar membrane inside the cochlea. other structures are also present. usually. |
|
|
Term
| how is the basilar membrane oriented? |
|
Definition
| high frequency sound is processed closest to the stapes, low frequency sound furthest. |
|
|
Term
| how do the tectorial membrane and the basilar membrane interact to activate hair cells? |
|
Definition
| the two have ofset pivot points, so the difference in position this creates bends hair cells and activates the associated neural pathways. |
|
|
Term
| how do hair cells activate from distortion? |
|
Definition
| the "hairs" of the cells have potassium channels that are tied to potassium channels on other hairs of the same cell. distortion opens all these channels resulting in depolarization, the opening of inward ca2+ channels and the resulting release of neurotransmitter vesicles |
|
|
Term
| do inner or outer hair cells send the majority of the information? |
|
Definition
|
|
Term
| what do outer hair cells do? |
|
Definition
| outer hair cells can provide otoacoustical emissions via movement of the basilar membrane. it is believed this is done for frequency tuning via efferent neurons from the superior olivary complex |
|
|
Term
| what is the fastest primary like neuron found in the auditory nerve can fire? |
|
Definition
|
|
Term
| what type of cells are present in the Dorsal cochlear nucleus and how do they fire?? |
|
Definition
| pyramidal cells and they are pausers |
|
|
Term
| what type of neurons are present in the Anterior ventral cochlear nucleus and how do they fire? |
|
Definition
spherical bushy cells- source like
Stellate cells- choppers
globular bushy cells- partially modified source like information |
|
|
Term
| what cells are found in the posterioventral cochlear nucleus and how do they fire? |
|
Definition
octopus cells- on only
inhibitory multipolar cells- chopping |
|
|
Term
| describe the pathway of auditory information in the brain. |
|
Definition
| cochlear hair cells innervate the auditory nucleus which goes to the spiral gangion - dorsal cochlear nucleus- superior olive(ipsi and contrilateral) -inferior colliculus via the lateral lemniscus - medial geniculate nucleus of the thalams- A1 |
|
|
Term
| where is spatial auditory information processed? |
|
Definition
| the medial superior olivary complex |
|
|
Term
| describe the neural pathway of the vestibular system |
|
Definition
| vestibular nucleus - ipsi and contrilateral thalamus - S1 layer 3a and to an area just behind s1 |
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