Tiff's Random Neuro Block 2

Front 1

olfactory bulb targets

Back 1

pyriform cortex
olfactory tubercle
amygdala
entorhinal cortex

Front 2

olfactory targets project to:

Back 2

entorhinal cortex --> hippocampal formation

all: thalamus, hypothalamus, orbitofrontal cortex

Front 3

lesion of path from thalamus to orbitalfrontal cortex

Back 3

unable to discriminate/perceive odors

Front 4

scratch and sniff test for Alzheimer's

Back 4

first sign of Alzheimer's is difficulty identifying common odors because of lesion between thalamus and orbitalfrontal cortex

Front 5

lesion of path to amygdala and hypothalamus

Back 5

emotional, motivational and visceral effects of odors -probs

Front 6

visceral motor responses to smell/olfaction:

Back 6

pleasant odors: salivation, increased GI motility, anticipation, fond memories
unpleasant/noxious: gagging, vomiting, aversive association and memories

Front 7

autonomic and reproductive responses to olfaction

Back 7

opposite gender attraction
perfumes and pheromones

Front 8

hyperosmia

Back 8

seizures
hysteria
iatrogenic

Front 9

how many taste cells make a taste bud? where are they localized?

Back 9

30-100
taste buds are localized to papillae in oral cavity

Front 10

how is gustatory sense transduced?

Back 10

ionic and 2nd messenger mediated gating of ion channels
-leads to depolarization and chemical transmission of receptor potential to gustatory afferent
*note that olfaction is only 2nd messenger G protein mediated

Front 11

labeled lined code--neural code for taste definition:

Back 11

taste cells and their afferent nerve fibers are specialists, responds to single taste ligands
prude prude prude

Front 12

describe central gustatory pathway

Back 12

CN7,9,10--> nucleus of solitary tract --> VPM of thalamus --> insula and frontal cortex --> amygdala
solitary tract also project to hypothalamus and amygdala

Front 13

function of anterior insula and frontal operculum cortex

Back 13

recognition
appreciation
subjective reaction

Front 14

hypothalamus and amygdala function in taste:

Back 14

appetite
satiety
emotional/motivational/visceral effects: salivation/pleasure/dislike/digestive actions/superior and inferior salivatory nuclei associated with CN7

Front 15

what is trigeminal chemoreception?

Back 15

polymodal nociceptors from CN 5, 9, 10 that convey GENERAL somatic sensory responses
activated by irritatns or toxins
input to SPINAL TRACT and NUCLEUS of CN 5
triggers pain and visceral effects like salivation, tearing, sweating, bronchoconstriction
concentration dependent

Front 16

number of functionally unique genetically encoded human odorant receptors

Back 16

350
can be highly selective (prude prude)
or slightly promiscuous (slut prude)

Front 17

combined activity of odorant receptors discriminate how many odors?

Back 17

10,000

Front 18

olfactory tract is made up of: (2 branches) which is main one?

Back 18

medial and lateral (main)

Front 19

eye has inner layer consisting of a neural and nonneural portion. the non-neural anterior potion consists of:

Back 19

iris and ciliary body

Front 20

middle layer of eye = uvea consists of:

Back 20

choroid
ciliary body
ciliary process
iris

Front 21

steps to eye development

Back 21

optic stalk from embryonic forebrain
invaginate to form optic vesicle --> cup becomes retina
vesicles induces ectoderm to form lens vesicle --> differentiate and overlying corneal epithelium
mesenchyme condenses to form vascular and connective tissue layers

Front 22

layers of cornea

Back 22

epithelium -stratified nonkeratinized squamous
bowman's membrane - acellular thick BM
substantia propria
Descemet's membrane
endothelium

Front 23

faulty drainage of this will cause glaucoma

Back 23

canal of schlemm

Front 24

aqueous humor is drained into:

Back 24

venous system

Front 25

iris is

Back 25

pigmented diaphragm w/ smooth mm
controls amount of light admitted via pupil
functions in accomodation
contains pigmented cells, loose connective tissue, vessels, separates anterior from posterior chamber

Front 26

pupillary sphincter -nerve innerv

Back 26

CNIII parasympathetics

Front 27

pupillary dilator - nerve innerv

Back 27

superior cervical ganglion
sympathetics

Front 28

adhesion of pigment epithelium

Back 28

from outer layer of optic cup
potential space from embryonic development, adhere strongly to choroid more than the rest of retina

Front 29

function of pigment epithelium

Back 29

absorbs scattered light rays
phagocytosis of worn out discs shed from rods
stores and releases VITAMIN A to photoreceptors

Front 30

outer segments of rods made up of:

Back 30

modified cilia, contain discs derived from outer PM of cilium vi

Front 31

visual pigments of cones sensitive to what colors?

Back 31

blue
green
red

Front 32

external limiting membrane is:

Back 32

specialized desmosome-like junctions btwn glial cells of retina nad photoreceptors
appears like line at LM level

Front 33

signal transmission in phototransduction

Back 33

receptor potentials (hyperpolarizing in light) by photoreceptors
slow grade potentials by bipolar cells
APs by ganglion cell layer

Front 34

rhodopsin is made from

Back 34

aldehyde of vit a
retinal + opsin

Front 35

AMD

Back 35

common cause of blindness in older individuals

Front 36

human ear is most sensitive to what frequency range?

Back 36

1200-4000 Hz

Front 37

why decrease audibility with age?

Back 37

lose auditory and vestibular hair cells
loss of ganglion cells
loss of hearing and balance esp high frequencies
20-30 db difference at 2000-4000 hz

Front 38

function of outer hair cells

Back 38

sharpen frequency
otoacoustical smissions

Front 39

endolymph
perilymph
inside cell
voltage in mVs?

Back 39

endolymph is 80 mV
perilymph is 0 mV
inside cell is -45 mV

Front 40

how does tip links start signal transduction?

Back 40

displace cells towards stria vascularis --> open cation selective channels --> depolarization
K+ influx from endolymph
Ca2+ entry
activates Ca-dependent K+ efflux
release of transmitter (glutamate_
8th nerve excitation/inhibition

Front 41

receptor potentials are proportional to:

Back 41

frequency of cilia shearing
frequency of BM vibration
frequency of soundwave

Front 42

olivocochlear input mechanism
able to block out background noise

Back 42

descending inhibition
near superior olivary nucleus
regulate flow of auditory input into CNS
terminates on hair cell/afferent fibers of IHC
cause OHC to contract --> auditory sensitivity/input responses
medial geniculate and auditory cortex send input to hair cells

Front 43

intensity encoding depends on:

Back 43

degree of movement of BM
intensity of hair movement
receptor potential
amount of transmitter released
firing rate and recruitment of 8th nerve

Front 44

2 ways of pitch interpretation

Back 44

one to one correlation
place theory

Front 45

one on one correlation

Back 45

low frequencies up to 3 kHz
volley theory: nerve cells fire in groups
the pattern of firing determines pitch
1 receptor potential --> 1 8th nerve fiber discharge

Front 46

place theory

Back 46

tonotopic organization
labeled line coding
each hair/neuron is tuned to a specific frequency

Front 47

medial superior olive responsible for

Back 47

interaural TIME DIFFERENCES
analyze difference in time to etermine where sound arises

Front 48

lateral superior olive

Back 48

interaural SOUND differences

**pontine vascular lesion and MS difficulty localizing sound

Front 49

acoustic startle reflex

Back 49

head sound, turn head
due to TECTOSPINAL TRACT
lateral meniscus connects superior olive of medulla to inferior colliculus of pons

Front 50

brachium of inferior colliculus innervates

Back 50

medial geniculate

Front 51

in conduction deafness: AC and BC?

Back 51

BC > AC

Front 52

causes of unilateral hearing loss

Back 52

EAC
cochlea
8th nerve
middle ear
cochlear nuclei
*once information enters brainstem info immediately crosses bilaterally at multiple levels

Front 53

treat otosclerosis by:

Back 53

microsurgery to make stapes mobile or replace stapes

Front 54

tx Meniere's

Back 54

antihypertensives and diuretics
-prevent rupture of membraneous labrynth

Front 55

otosclerosis caused by

Back 55

arthritis ossification of middle ear bones/neogenesis of labrynthine spongy bone
fixes stapes

Front 56

parts of cochlear implant

Back 56

microphone
speech processor
electrode array

Front 57

use cochlear implant when:

Back 57

pt is deaf with intact auditory nerve

Front 58

neurofibromatosis type 2

Back 58

tx by transect 8th nerve
must use brainstem inplant

Front 59

what disease with these sx?
nausea vomiting vertigo tinnitus

Back 59

meniere's

Front 60

nystagmus

Back 60

slow -opposite (vestibular)
fast - same (cortex)

Front 61

post rotary nystagmus

Back 61

slow - same side
fast - opposite side
spin 10x, stop suddenly

Front 62

past pointing

Back 62

in direction of head rotation

Front 63

tendency to fall

Back 63

in direction of head rotation

Front 64

spontaneous nystagmus

Back 64

pathology
lesion to labryinth, CN8, brainstem nuclei, flocconodular lobe of cerebellum

Front 65

vertigo

Back 65

opposite direction of original rotation

Front 66

irritative lesion

Back 66

slow-opposite
fast-same

Front 67

destructive lesion

Back 67

slow-same
fast return to opposite

Front 68

what condition causes:
canalithiasis
prevalent in adults
caused by sudden changes in position
test using dix hall-pike positional test

Back 68

benign paroxysmal position vertigo

Front 69

canalithiasis

Back 69

rocks in posterior and horizontal semicircular canal are LOOSE

Front 70

how do you treat canalithiasis?

Back 70

resposition loose canaliths CRPs

Front 71

what autonomic effects does vestibular stimulations cause?

Back 71

motion sickness
sweating pallor
nausea vomiting

Front 72

caloric test - test for

Back 72

vestibular function
brainstem integrity

Front 73

caloric test - method

Back 73

recline 60 degrees
horizontal canal is vertical
irrigate EAC with warm or cold water --> deflection of cupula/stimulate hair cells
irrigation perceived as profound unilateral stimulus

Front 74

Caloric test-normal response

Back 74

COWS
cold (Decrease firing) =fast to opposite
warm (increase firing)= fast to same
eyes move side to side if brainstem is intact

Front 75

caloric test - abnormal

Back 75

unequal response
good caloric - cortex prob
unilateral response = MLF lesion
no caloric response = brainstem prob

Front 76

positional vertigo test (dix-hallpike)

Back 76

vestibular dysfunction test
recline head face left or right
change position for max stimulation

Front 77

positional vertigo test -normal

Back 77

no nystagmus
no vertigo

Front 78

positional vertigo test-abnormal

Back 78

nystagmus with complaint of vertigo

Front 79

peripheral vertigo

Back 79

short onset delay with adaptation with repetition

Front 80

Central vertigo

Back 80

immediate
not adaptation

Front 81

oculocephalic doll's eye

Back 81

unconsciou patient
test vestibular function
passive movement of head side to side

Front 82

oculocephalic -normal

Back 82

eyes move oppositely to head

Front 83

oculocephalic abnormal

Back 83

eyes are fixed
brainstem/MLF prob

Front 84

ear develop from what?

Back 84

rhombencephalon (hindbrain)

Front 85

what is the spiral bony extension from modiolus and site of Basilar membrane attachment?

Back 85

spiral lamina

Front 86

saccades

Back 86

rapid ballistic movements of eyes that abruptly change point of fixation
cannot control velocity
voluntary, conjugate movements
commands originate in frontal cortex

Front 87

smooth pursuit movements

Back 87

much slower tracking movements of eyes designed to keep a moving stimulus on the fovea
under voluntary control, conjugate movement
originates in parietal-occipital cortex

Front 88

optokinetic nystagmus

Back 88

combination of smooth pursuit and saccadic correction
alternating slow and fast movement of eye in response to stimuli
normal reflexive response of eyes in response to large scale movements of visual scene and should not be confused with pathological nystagmus (Due to brain injury)
commands originate in occipital cortex
fixation on an object in visual field can suppress vestibulo-ocular reflex
requires an image on retina
reflex conjugate movements
commands originate in occipital cortex
fixation on object in visual field can suppress vestibulo-ocular reflex

Front 89

vergence movements

Back 89

align fovea of each eye with targets located at different distances from observer
linked with pupillary constriction and accomodation to keep image in focus (near triad)

Front 90

conjugate eye movement

Back 90

2 eyes move in same direction

Front 91

disconjugate eye movement

Back 91

vergence movements either convergence of divergence of lines of sight of each eye to see an object that is nearer or farther away

Front 92

vestibulo-ocular movements

Back 92

vestibular input keeps visual images fixed on retina during head movement
continuous input from semicircular canals
nystagmus resets eyes when reach limits of orbit
reflex conjugate movements
commands originate in vestibular nuclei

Front 93

vestibular control

Back 93

signals originating in semicircular canals drive vestibular input
directly input in abducens, trcholear, oculomotor not through gaze centers

Front 94

What is required for conjugate gaze?

Back 94

MLF

Front 95

what participates in control of eye movement through vestibular neurons?

Back 95

cerebellum

Front 96

_______ is the horiontal or lateral gaze center

Back 96

paramedian pontine reticular formation

Front 97

lateral gaze venter is important for what?

Back 97

control in saccade and pursuit for conjugate eye movements

Front 98

stimulation of PPRF drives the eyes to the:

Back 98

ipsilateral side

Front 99

destruction of PPRF results in

Back 99

paralysis of ipsilteral gaze

Front 100

vertical gaze center

Back 100

located in the rostral part of midbrain reticular formation
responsible for vertical movements

Front 101

lesion of right abducens nerve

Back 101

CN6 palsy
right eye cant move to right

Front 102

lesion of right abducens nucleus

Back 102

right lateral gaze palsy
both eyes cannot look right

Front 103

lesion of PPRF

Back 103

right lateral gaze palsy
both eyes cannot look right

Front 104

lesion of left MLF

Back 104

when looking right:
right eye nystagmus
left eye cannot look right

Front 105

lesion of left MLF and left abducens nucleus

Back 105

when looking right,
right eye nystagmus
left eye cannot look right
when looking left,
both eyes cannot look left
(left lateral gaze palsy)

Front 106

strabismus

Back 106

misalignment of eyes

Front 107

strabismus has what symptoms??

Back 107

diplopia due to
esotropia
exotropia

Front 108

esotropia

Back 108

weakness of lateral rectus causes eye to be pulled medially

Front 109

exotropia

Back 109

medial rectus is weak so lateral rectus is pressed laterally

Front 110

amblyopia

Back 110

constant diplopia
brain ignores input one eye and does not focus or orient the eye

Front 111

paralysis of lateral gaze of the left eye with ptosis together with hemi paresis on riaght side of body would be consistent with a vascular lesion of:

Back 111

the ventral midbrain

Front 112

INO internuclea ophthalmoplegia

Back 112

MLF lesion
the side of INO, is side of lesion
eye adduction on affected side is impaired with horizontal gaze but it often spared during convergence because inputs to oculomotor nucleus mediates convergence that arise from the pretectal region and does not travel in caudal MLF
may observe a slight lag in adduction of eye on affected side

Front 113

common causes of MLF

Back 113

MS plaques
also: pontine infarcts, neplasms

Front 114

one and a half syndrome

Back 114

MLF lesion on one eye
and abducens nucleus lesion on same side

Front 115

frontal eye fields controls what in eye movement?

Back 115

contralateral saccades via connections with contralateral PPRF

Front 116

parieto-occipito-temporal area controls what in eye movement?

Back 116

ipsilateral smooth pursuit via connections with vestibular nuclei, cerebellum, and PPRF
may make some contralateral eye movement contributions too

Front 117

what descending control of eye movement heavily influences visual inputs?

Back 117

primary visual cortex and visual association cortex

Front 118

vertical gaze venter is impotant for control of:

Back 118

saccades and pursuit conjugate eye movements

Front 119

___________ organize vertical conjugate eye movements

Back 119

mesencephalic reticular formation and pretectal area

Front 120

vertical eye movements require activity on both side of midbrain with communication through what?

Back 120

posterior commissure

Front 121

convergence of eyes is produced by

Back 121

medial recti

Front 122

divergence of eyes is produced by

Back 122

lateral recti

Front 123

disconjugate eye movements are organized in:

Back 123

midbrain, near oculomotor nucleus
based on retinal disparity

Front 124

accomodation and pupillary constriction is accomplished through retinal input to:

Back 124

optic tectum (superior colliculus) and Edinger-Westphal nucleus (parasympathetic)

Front 125

Parinaud's syndrome

Back 125

constellation of eye abnormalities usually seen with lesions compressing dorsal midbrain and pretectal area:
impaired vertical gaze especially upgaze
large irregular pupils, do not react to light
eyelid abnormalities
impaired convergence sometimes convergence-retraction nystagmus

Front 126

what is responsible for pupillary dilation?

Back 126

sympathetics

Front 127

what is responsible for pupillary constriction?

Back 127

parasympathetics

Front 128

what sympathetics are involved in pupillary dilation?

Back 128

superior cervical ganglion
carotid and ciliary ganglion
from T1-L2

Front 129

what parasympathetics?

Back 129

edinger-westpal
via oculomotor nerve to ciliary ganglion

Front 130

pupillary light reflexes

Back 130

direct/consensual reflexes to light in one eye
pupil size is determined by a balanced input of both sympathetic/parasympathetic systems
accomodation response

Front 131

miosis

Back 131

small pupil - loss of sympathetics

Front 132

mydriasis

Back 132

dilated pupil - loss of parasympathetics

Front 133

anisocoria

Back 133

pupillary asymmetry

Front 134

Argyll-Robertson pupil

Back 134

accommodating
will constrict on vergence
not responsive to light
result of tertiary syphilis, alcoholism, encephalitis

Front 135

Horner's syndrome is caused by what kind of nervous damage?

Back 135

sympathetics

Front 136

a vascular infarct of what could cause horner's?

Back 136

PICA - dorsal lateral medulla infarct

Front 137

nonvascular causes of horner's

Back 137

spinal cord injury usually trauma
sympathetic chain injury or trauma
T1 and T2 spinal roots, apical lung tumor
carotid plexus - carotid dissection
cavernous sinus - thrombosis, infection, tumors, aneurysms
orbit infection or neplasm

Front 138

Cause of Parinaud's syndrome

Back 138

tumor of pineal gland
hydrocephalus can increase pressure of optic tectum of midbrain(pushes down by dilation of 3rd ventricle)

Front 139

parinaud's syndrome has paralysis of:

Back 139

upward gaze (cannot elevate eye)
paralysis of convergence

Front 140

common causes of visual loss

Back 140

optical (refractive errors)
medial opacities (cataracts)
retinal disease (macular degeneration/diabetic retinopathy)
optic nerve diseases (glaucoma/optic neuritis)
CNS (ischemia-CVA)

Front 141

visual acuity

Back 141

ability to see detail
as measured on eye chart

Front 142

dyschromatopsia

Back 142

inability to distinguish colors
"color blindness"

Front 143

scotoma

Back 143

small (visual field defect)

Front 144

anopsia

Back 144

larger (visual field defect)

Front 145

agnosia

Back 145

inability to recognize, name objects

Front 146

what is needed for good visual acuity?

Back 146

1. proper focus of light rays on macula
2. clear media - cornea/lens/vitreous
3. healthy macula and optic nerve

Front 147

refractive errors

Back 147

light rays coming in from a distance
if not focused on retina, image will be blurred

Front 148

myopia

what lenses to correct?

Back 148

near sighted

minus power lenses needed

Front 149

hyperopia

Back 149

far sighted

plus power lenses needed

Front 150

astigmatism

Back 150

not a disease but a complicated optic error where there are multiple focal points because cornea is not perfectly spherical
poor focus near and far
need special cylinder lens

Front 151

cataracts cause

Back 151

loss of visual acuity
no specific visual fields loss

Front 152

macula

Back 152

contains fovea
allows for sharp and detailed vision

Front 153

macular degeneration

Back 153

loss of central acuity
still can have ambulatory vision

Front 154

retinitis pigmentosa

Back 154

loss of night vision
loss of peripheral vision

Front 155

papilledema

Back 155

optic nerve head (disc)
swelling due to high intracranial pressure

Front 156

glaucoma

Back 156

increased cupping of disc
loss of RIM OF NEURO-RETINAL TISSUE (ganglion cell axons)
comprise nerve tissue of optic nerve

Front 157

optic neuritis

Back 157

often caused by MS

Front 158

optic atrophy

Back 158

loss of axons

Front 159

describe rods

Back 159

higher sensitivity
low light levels
monochromatic
peripheral vision

Front 160

describe cones

Back 160

bright light
color
detailed central vision

Front 161

color vision - cones have 3 types of pigment:

Back 161

red
green
blue

Front 162

dichromats

Back 162

red or green deficiency most common

Front 163

monochomats

Back 163

see only one cone pigment or no cones just rods or even a cerebral deficit

Front 164

hereditary dyschromatopsias

Back 164

5-6% males have some color vision loss
usually red/green discrimination deficit
X-linked

Front 165

acquired dyschromatopsias

Back 165

can be red/green or blue/yellow
sign of macular disease or optic nerve disease
e.g. optic neuritis

Front 166

projections of retinal ganglion to:

Back 166

lateral geniculate nucleus
hypothalamus (suprchiasmatic nucleus)
superior colliculus (saccadic eye movements)
pretectum (pupillary eye reflex)

Front 167

lateral geniculate involved in

Back 167

vision

Front 168

hypothalamus (suprachiasmatic nucleus) involved in

Back 168

circadian rhythms

Front 169

superior colliculus

Back 169

coordination of head and eye movements

Front 170

pretectum

Back 170

pupillary eye movements

Front 171

projections of retinal ganglion to:

Back 171

lateral geniculate nucleus
hypothalamus (suprchiasmatic nucleus)
superior colliculus (saccadic eye movements)
pretectum (pupillary eye reflex)

Front 172

main visual pathway

Back 172

ganglion cells --> LGN --> occipital cortex
2 neuron pathway

Front 173

lateral geniculate involved in

Back 173

vision

Front 174

optic radiations

Back 174

2 parts
meyer's loop in temporal lobe (superior visual field)
fibers representing superior retinal quadrants (inferior visual field)

Front 175

hypothalamus (suprachiasmatic nucleus) involved in

Back 175

circadian rhythms

Front 176

extra-striate visual areas

Back 176

occipital lobe not dead end
dorsal pathway - parietal lobe
ventral pathway - temporal lobe

Front 177

superior colliculus

Back 177

coordination of head and eye movements

Front 178

parietal lobe involved in:

Back 178

spatial vision and movement processing

Front 179

pretectum

Back 179

pupillary eye movements

Front 180

temporal lobe involved in:

Back 180

object recognition
color appreciation

Front 181

main visual pathway

Back 181

ganglion cells --> LGN --> occipital cortex
2 neuron pathway

Front 182

optic radiations

Back 182

2 parts
meyer's loop in temporal lobe (superior visual field)
fibers representing superior retinal quadrants (inferior visual field)

Front 183

extra-striate visual areas

Back 183

occipital lobe not dead end
dorsal pathway - parietal lobe
ventral pathway - temporal lobe

Front 184

parietal lobe involved in:

Back 184

spatial vision and movement processing

Front 185

temporal lobe involved in:

Back 185

object recognition
color appreciation

Front 186

projections of retinal ganglion to:

Back 186

lateral geniculate nucleus
hypothalamus (suprchiasmatic nucleus)
superior colliculus (saccadic eye movements)
pretectum (pupillary eye reflex)

Front 187

lateral geniculate involved in

Back 187

vision

Front 188

hypothalamus (suprachiasmatic nucleus) involved in

Back 188

circadian rhythms

Front 189

superior colliculus

Back 189

coordination of head and eye movements

Front 190

pretectum

Back 190

pupillary eye movements

Front 191

main visual pathway

Back 191

ganglion cells --> LGN --> occipital cortex
2 neuron pathway

Front 192

optic radiations

Back 192

2 parts
meyer's loop in temporal lobe (superior visual field)
fibers representing superior retinal quadrants (inferior visual field)

Front 193

extra-striate visual areas

Back 193

occipital lobe not dead end
dorsal pathway - parietal lobe
ventral pathway - temporal lobe

Front 194

parietal lobe involved in:

Back 194

spatial vision and movement processing

Front 195

temporal lobe involved in:

Back 195

object recognition
color appreciation

Front 196

projections of retinal ganglion to:

Back 196

lateral geniculate nucleus
hypothalamus (suprchiasmatic nucleus)
superior colliculus (saccadic eye movements)
pretectum (pupillary eye reflex)

Front 197

lateral geniculate involved in

Back 197

vision

Front 198

hypothalamus (suprachiasmatic nucleus) involved in

Back 198

circadian rhythms

Front 199

superior colliculus

Back 199

coordination of head and eye movements

Front 200

pretectum

Back 200

pupillary eye movements

Front 201

main visual pathway

Back 201

ganglion cells --> LGN --> occipital cortex
2 neuron pathway

Front 202

optic radiations

Back 202

2 parts
meyer's loop in temporal lobe (superior visual field)
fibers representing superior retinal quadrants (inferior visual field)

Front 203

extra-striate visual areas

Back 203

occipital lobe not dead end
dorsal pathway - parietal lobe
ventral pathway - temporal lobe

Front 204

parietal lobe involved in:

Back 204

spatial vision and movement processing

Front 205

temporal lobe involved in:

Back 205

object recognition
color appreciation

Front 206

what would cause a unilateral visual defect?

Back 206

retinal disease
degenerative/ischemic
optic nerve disease: glaucoma, optic neuritis, ischemia

Front 207

macular degeneration

Back 207

central field loss

Front 208

ophthalmoplegia can be caused by

Back 208

internal: iris and ciliary body muecles

external: extraocular muscles

Front 209

pupillary light reflex pathway

Back 209

Optic Nerve
Optic Chiasm
Crossing Over Occurs
Pretectum
Crossing over occurs
Edinger-Westphal Nuclei
Joins IIIrd Cranial Nerve
Ciliary Ganglion
Pupillary Sphincter muscle

Front 210

relative afferent pupillary defect (RAPD)

Back 210

unilateral afferent dysfunction results in diminished efferent impulses traveling back to both pupils

Front 211

anisocoria

Back 211

damage to iris/pupil, surgery, glaucoma, trauma
pharmacologic
toxic
efferent pathway problem

Front 212

Marcus Gunn pupil relative afferent pupil defect

Back 212

several optic nerve diseases
optic neuritis
other optic nerve disease: tumor/ischemia/infarctions/optic atrophy
some retinal disease - ischemia
Central retinal artery occlusion

Front 213

parasympathetics control:

Back 213

pupil constriction
accomodation
3rd CN, ocular motility
eyelid retraction

Front 214

sympathetics control

Back 214

pupil dilation
lid elevation
sweating

Front 215

horner's syndrome sx

Back 215

ptosis
miosis
anhydrosis

Front 216

CN3 controls these muscles

Back 216

levator palpebrae
superior rectus
inferior rectus
inferior oblique
medial rectus

Front 217

CN4

Back 217

superior oblique

Front 218

CN6

Back 218

lateral rectus

Front 219

fxn of superior oblique

Back 219

primarily intorsion

some depression

Front 220

fxn of inferior oblique

Back 220

primarily extorsion

some elevation

Front 221

ductions

Back 221

single eye movements
adduction
abduction
infraduction
supraduction
excycloduction
incycloduction

Front 222

versions

Back 222

movement of both eyes
convergence/divergence

Front 223

fixation

Back 223

keeping eye steady on a visual target
maintaining image on fovea of a stationary target

Front 224

VOR

Back 224

maintain fixation with head movements

Front 225

saccades

Back 225

sudden rapid ballistic movements to refixate
-rapid eye movements to fixate on a stationary object of regard

Front 226

smooth pursuit

Back 226

maintain stable eye tracking of a slowly moving object

Front 227

optokinetic (nystagmus)

Back 227

stabilize retinal image during sustained head rotation
following fast moving objects

Front 228

INO

Back 228

lesion to MLF
producing ipsalateral adduction deficit

Front 229

left gaze palsy

Back 229

lesion in left PPRF or left 6th nerve nucleus

Front 230

right gaze palsy

Back 230

lesion in right PPRF or right 6th nerve nucleus

Front 231

dorsal midbrain syndrome

Back 231

cannot look up
compress rostral midbrain RF and pretectal area

Front 232

study of brain waves during sound stimuli

Back 232

BAER

Front 233

what can cause unilateral hearing loss?

Back 233

any disease affecting middle and inner ear apparatus or
cranial nerve 8
ex: otitis media, otosclerosis, Meniere's, presbyacusis, acoustic schwannoma

Front 234

what neurological systems are necessary to maintain balance?

Back 234

proprioception-vibration sysem (dorsal columns)
visual system
vestibular-midline cerebellum system

Front 235

poor speech discrimination suggests where is lesion?

Back 235

cochlear nerve or most rostral parts of auditory pathway

Front 236

what would result in problems closing left eye tightly?

Back 236

facial nerve lesion

Front 237

corneal reflex -afferent/effent limb?

Back 237

afferent is trigeminal ophthalmic division
efferent is facial nerve

Front 238

well circumscribed enhancing lesion without surrounding edema extending from internal auditory canal into left cerebello-pontine angle

Back 238

acoustic schwannoma

Front 239

what would acoustic schwannoma cause in BAE?

Back 239

wave I (auditory nerve) and wave II (cochlear nucleus in pns) would cause prolongation in interlatency difference between Wave I and II

Front 240

due to disturbance of vestibular apparatus of inner ear

Back 240

peripheral vertigo

Front 241

due to CNS disturbance

Back 241

central vertigo

Front 242

• Slow onset of hearing loss in left ear
• Odd sensation of fullness in back of his head
• Unsteady when walking especially after a quick turn
• Mild balance and agility problems
• Hissing noise became progressively worse in left ear
• Stooping → dizziness and loss of balance

Neuro exam
• Definite hearing loss on left
• Poor speech discrimination and decreased perception of loud noises
• Weber lateralize to the right
• Depressed direct corneal reflex on left
• Depressed consensual reflex on right
• Facial sensation normal
• Left face mildly weaker than right

Back 242

acoustic schwannoma

Front 243

sensation of motion of self or surrounding

Back 243

vertigo

Front 244

mild
nystagmus is multidirectional
nonfatiguable
abrupt in onset
long duration

Back 244

central vertigo
due to brainstem problem

Front 245

perception of abnormal sounds in ear like buzzing, humming, whistling, roaring, clicking, hissing pulselike

Back 245

tinnitus

Front 246

nonvibratory tinnitus

Back 246

only heard by patient
implies disease of middle ear, inner ear or 8th cranial nerve

Front 247

vibratory tinnitus

Back 247

conduction of sound from other structure of head and neck, vascular bruit, repetitive contraction of muscles of palate, ear popping

Front 248

defect in amplification and conduction due to diseases process of outer/middle ear

Back 248

conductive hearing loss

Front 249

sensorineural loss

Back 249

disease of cochlear and auditory nerve

Front 250

why does lying on right side help vertigo?

Back 250

allow to easily look toward affected side to decrease amount of subsequent nystagmus
suggesting left labryinth is probably effected

Front 251

fast beating nystagmus suggests what?

Back 251

slow phase (vestibular) to left
fast phase to right (cerebral cortex provides corrective saccade to opposite direction)

Front 252

• Whistling in ear
• Hearing loss
• Room spinning
• Nausea and vomiting
• Climbed in bed, more comfortable on right side with eyes open
• Normal mental status
• Bilateral hearing loss with relative preservation of speech discrimination
• Whistling in ears
• Other CNs are normal
• Increased whistling
• Middle attack of spinning during physical exam
• Nystagmus was noted, fast beating to right
what is dx?

Back 252

Meniere's

Front 253

what CN would be affected with a large tumor in the cerebellar pontine angle?

Back 253

5, 7, 8

6 is more ventral

Front 254

39 yo is unconscious but responds to pain stimuli
cold calorics in both ears provokes no nystagmus
both eye moves slowly to side irrigated and remain there
these finding are indicative of damage limited to:

Back 254

cortex drives fast phase

Front 255

33 yo male suffers severe trauma to left side of his head that destroys the inner ear cochlea and labyrinth. During early stages of his recovery he is unsteady and has poor balance. 6 months later, no longer has deficits in balance

Back 255

the right labyrinth compensates by decreasing its function
visual and proprioceptive systems increase function to compensate

Front 256

under normal circumstances, irrigating a patient’s left external adutory meatus with warm water would elicit:

Back 256

left beating nystagmus
fast phase of nystagmus is same as side of irrigation

Front 257

cluster of nuclei in caudal pons is the first to receive binaural input and responsible for localization of sound:

Back 257

superior olive

Front 258

in an unconciscous patient caloric testing reveals:
cold water in right ear causes right eye to look right but left eye does not move.
cold water in left ear causes left eye to look left, right eye does not move where is the likely location of lesion?

Back 258

MLF bilateral

Front 259

Meniere's is also called

Back 259

endolymphatic hydrops

Front 260

4 yo presented with painful earache, fever, complained of right ear was touched
drum was red and inflamed suggesting infection and infection of middle ear
what do you expect to be the child’s condition

Back 260

dysfunctional eustachian tube

Front 261

53 yo man noticed that hearing in his right ear was deteriorating
could not hear a watch ticking on right
left side as normal

Back 261

conduction deafness
most likely otosclerosis

Front 262

45 yo man who went to see his family physician for a life insurance exam
he is a hunter. His pure tone right ear audiogram indicated peripheral abnormality

Back 262

evidence of a sensorineural hearing loss

Front 263

65 yo diabetic woman has aphasia secondary to stroke involving inferior division of left middle cerebral artery
hearing is intact
temporal lobe infarction will not produce complete deafness because

Back 263

each cochlear nerve projects to BOTH temporal lobes

Front 264

13 yo has a severe case of left sided mastoiditis
develops a fluent aphasia
aphasia is most likely the result of extension of the infection into the

Back 264

temporal lobe
Wernicke's

Front 265

52 yo man on multiple medication medications develops temporary hearing loss which agent?

Back 265

aspirin

Front 266

50 yo man is evaluated for tinnitus
worse on some days than others
which of the following may exacerbate tinnitus?

Back 266

think auditory
aspirin quinine
aminoglycosides

Front 267

21 yo right handed woman works at airport as a luggage handler
ear protection must be worn to protect against hearing loss and development of

Back 267

tinnitus

Front 268

what is dissociated sensory loss?

Back 268

regional sensory loss that involves only one of 2 primary sensory modalities with sparing of the other

Front 269

electric shocklike sensation spreading down body or into back or extremities when she flexes her neck is:

Back 269

Lhermitte's sign

Front 270

what causes Lhermitte's sign?

Back 270

lesion of cervical spinal cord due to:
MS, tumor, herniated disc, body ridge indenting cord

Front 271

what kind of lesion can cause Horner's?

Back 271

caused by lesion to sympathetic nerve fibers that innervate face
-caused by ipsilateral lesion inhypothalamus, brain stem reticular formation, cervical and upper thoracic spincal cord, superior cervical ganglion, sympathetic fibers running along carotid artery and branches of cranial nerve V

Front 272

what are all the possible levels of neuraxis at which a lesion can produce this triad?

Back 272

lower cervical and upper thoracic spinal cord

Front 273

what muscles elevate the eyelid?

Back 273

levator palpebrae
superior tarsal muscle

Front 274

levator palpebrae is innervated by

Back 274

CN III (voluntary)

Front 275

superior tarsal muscle

Back 275

involuntary, sympathetic nervous system

Front 276

left leg hyperreflexi and increased muscle tone suggests:

Back 276

upper motor dysfunction due to ipsilateral lesion affecting left corticospinal tract in cervical and thoracic spinal cord

Front 277

plantar response

Back 277

superficial NOCICEPTIVE reflex elicited by stroking the lateral plantar surface of foot from heel toward the ball of foot
normal: plantar flexion of great toe
babinski's is abnormal, extension of groeat toe IMPLIES UPPER MOTOR NEURAL LESION involving corticospinal tract

Front 278

abdominal reflexes

Back 278

superficial NOCICEPTIVE reflexes obtained by stroking skin lightly on abdomen from umbilicus toward any abdominal quadrant
look for deviation of umbilicus toward the quadrant stroked
absence of abdominal reflexes on one side suggest UMN dysfunction and roughly equivalent to extensor plantar response

Front 279

lesion in left cervical spinal cord can produce ipsilateral upper motor neuron dysfunction, ipsilateral dorsal column sensory dysfunction and contralateral spinothalamic sensory dysfunction
this is called

Back 279

Brown sequard's syndrome

Front 280

where does the dorsal columns pathway cross?

Back 280

internal arcuate fibers of medulla

Front 281

where does anterolateral pathway cross?

Back 281

right when enter spinal cord and synapse at dorsal horn, anterior white commissure

Front 282

lower motor neuron dysfunction is associated with

Back 282

decreased muscle bulk
hypoactive muscle stretch reflexes

Front 283

upper motor neuron dysfunction is associated with

Back 283

hyperactive and plantar response to be extensor (babinski)

Front 284

where can you get a single lesion that affects BOTH right and left anterolateral pathways

Back 284

anterior white commissure

Front 285

• Both hands lost muscle bulk
• Right neck pain that radiates down right arm and describes a burning in quality
• Burned right hand and forearm
• Decreased muscle bulk in intrinsic muscles bilaterally and left forearm
• Mild spastic catch in both legs
• Lower extremity strength is normal bilaterally
• Loss of thermal sense and pinprick over posterior neck and shoulders extending down both arms in “capelike” fashion
• Plantar response is extensor on right (Babinski) and flexor on left
• Gait is normal

Back 285

due to central lesion in cervical spinal cord such as syrinx

Front 286

list 3 regions that can produce a left hemibody sensory loss

Back 286

right parietal cortex
right corona radiata
right thalamus

Front 287

left-sided neglect is caused by

Back 287

ability to attend to hemispatial field is a function of CONTRALATERAL PARIETAL LOBE

Front 288

pronator drift is specific to what kind of dysfunction?

Back 288

upper motor neuron

Front 289

sensory drift

Back 289

profound loss of sensation resulting in inability to localize in space

Front 290

profound hemisensory lesions that split the midline are often seen where?

Back 290

THALAMUS where the sensory inputs converge
can localize to right thalamus in lateral and medial division of VPL and VPM
sensory relay nuclei relay somatosensory/facial sensory information to primary sensory cortex

Front 291

what supplies the thalamus?

Back 291

thalamogeniculate branches of PCA (right lateral thalamus)

Front 292

thalamic pain syndrome (Dejerine-Roussy)

Back 292

involvement of VPL and VPM of thalamus
usually due to vascular lesion--> distressing spontaneous pain and discomfort on side of contralateral lesion

Front 293

truncal sensory level

Back 293

diminished sensation from all dermatomes below a particular dermatome on the trunk

Front 294

tertiary syphilis can cause

Back 294

deficits in fine touch vibratory proprioceptive sens

Front 295

T4 vertebral fracture at what spinal level would these deficits in pain and thermal sense be greatest?

Back 295

T6 and lower
anterolateral tract lesion distribute info rostrally
complete loss 2-3 segments below

Front 296

Brown-sequard syndrome

Back 296

results in dissociated sensory loss
DORSAL-VENTRAL hemisection of spinal cord

Front 297

why can a spinal cord lesion produce horner's?

Back 297

fibers from hypothalamus descend in spinal cord to control preganglionic sympathetic neurons

Front 298

a patient revels deficits in sensation of vibration, fine touch, proprioception but NO EVIDENCE of CNS lesion
you suspect a peripheral neuropathy involving what kind of fibers?

Back 298

A-beta fibers

Front 299

Anterolateral tracts are primarily served by what class of peripheral nerve fibers?

Back 299

group 3 and 4

Front 300

A delta fibers convey

Back 300

initial response, first pain that leads to STT, is fed by a-delta fibers to check the integrity of the anterolateral system

Front 301

slow persistent pain is conveyed by

Back 301

C fibers

Front 302

A pt presents with hypoesthesia to thermal and nociceptive sensations in a capelike distribution across both shoulders and both arms?

Back 302

anterior white commissure

Front 303

syringomyelia

Back 303

central cavitation of spinal cord

Front 304

18 yo male present with dissociated segmental deficits in thermal/pain sensation across both arms hyperreflexia and spasticity with weakness and atrophy of arm and hand muscles

Back 304

cervical syrinx has UMN AND LMN damage
herniated disk is ONLY LMN damage

Front 305

what is the comorbidity to a cervical cord syrinx?

Back 305

herniation of cerebellar tonsils (chiari malformation)

Front 306

54 yo hypertensive and diabetic female complains of several recent episodes of paresthesias in right arm and shoulder

Back 306

transient ischemic attacks

Front 307

59 yo male suffers stroke resulting in complete LEFT side hemibody sensory loss of modalities but NO motor impairment. Based only on this info, what are possible sites of lesion

Back 307

right posterior parietal cortex, right corona radiata/internal capsule/right thalamus/right dorsal pons
where do sensory tracts run together? Both the DC-ML and AL tracts run together in a VERY small region in the dorsal pons → thalamus → corona radiata/internal capsule → posterior pariteal cortex

Front 308

same male stroke resulting in complete left side hemibody sensory loss of modalities but no motor impairment and no left-sided sensory neglect. What structure can you now eliminate from you list of possible sites?

Back 308

Right parietal cortex – involved in space and spatial representation

Front 309

Same guy suffers a stroke resulting in complete left side hemibody sensory loss of all modalities but NO motor impairment
The lack of motor signs allows to diminish which of the following potential lesion site

Back 309

corona radiata and internal capsule

Front 310

Same guy suffers a stroke resulting in complete left side hemiody sensory loss of all modalities but not motor impairment and NO cranial nerve deficits

Back 310

right dorsal pons would cause CN deficits
must be thalamus

Front 311

Stroke 9 mo ago and reports episodes of severe burning and stabbing on right side of his body where was stroke?
Especially shoulder arm and torso

Back 311

left VPL nucleus of thalamus
thalamic pain syndrome

Front 312

A stroke results in complete left side hemibody sensory loss of all modalities, no motor impairment and no cranial nerve deficits. Nine months later he develops thalamic pain syndrome
What arteries most likely compromised?

Back 312

right thalamoperforator and thalamogeniculate

Front 313

known risk factors for stroke

Back 313

high blood cholesterol
high LDL
hypertension
diabetes
peripheral artery disease
coagulation disorder

Front 314

medial medulla is supplied by

Back 314

paramedian branches of vertebral and anterior spinal arteries

Front 315

lateral medulla

Back 315

verebral artery
or more commonly PICA

Front 316

anatomical structures found in the medial medulla

Back 316

pyramidal tract
medial lemniscus
hypoglossal nucleys and exiting CNXII fascicles

Front 317

anatomical structures found in lateral medulla

Back 317

inferior cerebellar peduncle
vestibular nuclei
trigeminal nucleus
spinothalamic tract
desceding sympathetic fibers
nucleus ambiguus
nucleus solitarius

Front 318

medial medullary syndrome -symptoms

Back 318

contralateral arm or leg weakness
contralateral decreased position and vibration sense

Front 319

lateral medullary syndrome (Wallenberg's syndrome) symptoms

Back 319

ipsilateral ataxia, vertigo, nystagmus nausea
ipsilateral facial decreased pain and temp
cnotralateral body decreased pain and temp
ipsilateral horner's
hoarseness dysphagia
ipsilateral decreased taste

Front 320

lateral caudal pons supplied by

Back 320

AICA

Front 321

dorsolateral rostral pons supplied by

Back 321

SCA

Front 322

Weber's syndrome

Back 322

branches of PCA and top of basilar artery infarct
causes oculomotor nerve ipsilateraly palsy
contralateral hemiparasis due to cerebral peduncle

Front 323

midbrain tegmentum is supplied by

Back 323

PCA and basilar
cause of Claude's syndrome

Front 324

an infarct in PICA can cause what?

Back 324

Lateral medullary syndrome or Wallenberg's

Front 325

what are the symptoms?

Back 325

ipsilateral ataxia vertigo nystagmus
ipsilateral facial decreased pain and temperature
contralateral body decreased pain and temperature sense
ipsilateral horner's syndrome
hoarseness and hysphagia
ipsilateral decreased taste

Front 326

lesion of oculomotor nerve fascicles

Back 326

ipsilateral third nerve palsy

Front 327

lesion of vestibular nuclei causes

Back 327

vertigo
nystagmus

Front 328

trigeminal nucleus and tract lesion causes

Back 328

ipsilateral facial decreased pain and temperature sensation

Front 329

facial colliculus lesion causes

Back 329

ipsilateral face weakness
ipsilateral horizontal gaze palsy

Front 330

lesion of hypoglossal nucleus and its existing fascicles

Back 330

ipsilateral tongue weakness

Front 331

lesion of nucleus solitarius

Back 331

ispilateral decreased taste

Front 332

lesion of descending sympathetic fibers

Back 332

Horners syndrome

Front 333

radiculopathy

Back 333

pain or neuro abnormality in a dermatome

Front 334

absent ankle reflex caused by

Back 334

S1

Front 335

subjective weakness plantar flexion caused by

Back 335

S1

Front 336

slight numbness left posterolateral leg

Back 336

L5, S1

Front 337

main cause of back pain in 30 yo

Back 337

musculoskeletal
herniated disc

Front 338

40 yo cause of back pain

Back 338

degeneration, infection, ovarian cancer, pancreatitis

Front 339

over 50 yo cause of back pain

Back 339

metastatic cancer
spinal stenosis
rheumatoid diseases
abdominal aneurysm
myeloma

Front 340

does most back pain arise from herniated disc?

Back 340

NO
3% of herniated discs require surgery

Front 341

distinguish low back pain from radiculopathy

Back 341

radiculopathy is defined as an abnormality involving a nerve root (pain in a dermatomal pattern)
back pain: pain arising from muscle or peripheral nerve entrapment (no radiating pain to limbs)

Front 342

left S1 radiculopathy with pain radiating to the left posterolateral leg and lateral foot
numbness in a left S1 dermatomal pattern and absent Achilles reflex (S1)
sensory and motor changes
weakness if subtle

Back 342

findings due to physical compression or irritation of nerve root by herniated disc

Front 343

review tx options for radiculopathy

Back 343

opioid based analgesic
hydrocodone
acetaminophen
stronger NSAID
physical therapy is optional

Front 344

most common psychiatric disorders in patients with lower back pain

Back 344

depression
generalized anxiety disorder
somatization disorder
personality disorder

Front 345

paracentral disc herniation of left lateral L5-S1 will cause impingement of what nerve root?

Back 345

S1 nerve root

Front 346

is this acute or chronic?
low back pain with left S1 radiculopathy
left herniated disc at L5/S1
mild neurological findings

Back 346

acute pain

Front 347

Tx for persistent pain

Back 347

epidural injection of steroids and local anesthetics may provide good pain relief
effect on DRG -irritating
anti-inflammatory mechanism most well-established

Front 348

inflamed ganglion demonstrates upregulation of:

Back 348

opiod receptors
sodium channels
NK1 receptors whe

Front 349

when do you consider surgery for back pain?

Back 349

disc is concordant with sx
pain is radicular
adequate time for healing has passed
risk factors for surgery are appropriate
back pain alone responds less well

Front 350

gate control theory

Back 350

activity on large diameter afferents can inhibit activity on small diameter pain transmission neurons
occurs in DH
requires inhibitory interneurons

Front 351

what is the basis for counter irritatns to relieve pain?

Back 351

gate control theory

Front 352

what type of fibers have the lowest threshold

Back 352

large fibers

Front 353

PAG send output to monoaminergic nuclei in medulla to:

Back 353

Raphe (serotonin)
locus coeruleus (NE)

Front 354

monoaminergic fibers descend in dorsolateral region of SC to terminate on dorsal horn
similar projections to:

Back 354

caudal spinal nucleus of CN5

Front 355

2 ways to block pain transmission via NE/5-HT

Back 355

1.excite interneurons --> release enkephalin --> inhibit pain transmission at synaptic junction where glutamate and substance P are released
2. may synapse directly on pain transmission fibers to inhibit impulse

Front 356

stress induced analgesia
give examples

Back 356

anticipatory, preparatory, emtional stress
physical exertion and exercise
acupuncture/acupressure
placebo

Front 357

how does stress induced algesia work?

Back 357

via hypothalamus and limbic system (amygdala)
opiates and non-opiate mechanisms are involved

Front 358

PAG receives descending input from:

Back 358

RF, STT, SRT, SMT
implanted electrodes
opiate drugs (morphine)
stress and anxiety (limbic system/endocannabinoids)

Front 359

PAG send out descending projection to synapse at:

Back 359

raphe magnus --> dorsolateral spinal cord/spinal nucleus of 5 --> dorsal horn --> serotonin to enkephalin interneurons --> inhibit pain transmission
locus coeruleus --> lateral spinal cord/spinal nucleus of CN5 --> dorsal horn --> NE to enkephalin interneurons --> inhibit pain transmission

Front 360

what type of pain is NOT pathological

Back 360

somatic superficial pain

Front 361

yperalgesia

Back 361

enhanced pain response to noxious stimuli after injury
primary at site of injury
2ndary at surrounding sit of injury due to spread of chemical mediators

Front 362

allodynia

Back 362

severe sensitization to extend that normal non-noxious stimuli are painful

Front 363

what type of pain is slow, generally localized emotional, motivational

Back 363

persisting: can be inflammatory vs. neuropathic
caused by inflammation
OR altered receptor, damaged nerve, facilitated CNS transmission

Front 364

what type of pain persists beyond healing period
profoundly altered receptor, nerve or CNS pathways

Back 364

abnormal/chronic

Front 365

TRPV1

Back 365

legitimate polymodal receptor
elicits intense burning pain sensation
concomitant exposure to 2 or more adequate stimuli --> hyperalgesia or allodynia

Front 366

TRPV1 responds to:

Back 366

capsaicin
low pH (H+)
heat

Front 367

inflammatory pain (peripheral)

Back 367

sensitized peripheral receptors
chemical mediators (cytokines and chemical that decrease threshold of nociceptors)
primary afferent cell surface receptors and receptive intracellular signaling
pharmacologic basis for analgesic (NSAIDS)

Front 368

neuropatic pain (peripheral)

Back 368

damage/demyelination
ectopic impulse generation via pseudoreceptors/short circuits
barrage of input from recurrent excitation in local circuit
transcriptionally altered primary afferents
C fibers express MORE nociceptors
large fibers begin to convey nociceptive input

Front 369

Central desensitization

Back 369

damage to peripheral nerves
Abeta fibers rearrange termination to make MORE synapses with nociceptive relay neurons
altered secondary relay neurons
new receptors are expressed for NTs of primary pain afferents: glutamate/substance P
altered electrophysiology
Reverberation (thalamic syndrome)
damage to descending inhibitory pathways
nonnociceptive central pathways take on role of conveying nociception

Front 370

what is a key component of PERSISTENT NEUROPATHIC PAIN

Back 370

central desensitization

Front 371

CRPS1

Back 371

complex regional pain syndrome
no identifiable nerve injury

Front 372

how do you treat central sensitization

Back 372

opiods dont work well
gabapentin, pregabalin, tricyclic antidepressants are effective

Front 373

CRPS2

Back 373

identifiable nerve trauma/disease --> neuropathic pain

Front 374

what is the etiology of CRPS?

Back 374

unknown etiology
NE activates and sensitives nociceptors
cytokine abnormality
autoimmune

Front 375

visceral pain is conveyed by

Back 375

anterolateral system
dorsal columns-ML
spinocervical -ML

Front 376

referred visceral pain

Back 376

poorly localized
convergence of 2 or more primary afferents
superficial receptive field onto visceral receptive field
spread via Lissauer's
conveyed by AL system

Front 377

brain interpretes input as coming from a familiar region

Back 377

referred pain

Front 378

phantom limb

Back 378

brain remembers missing limb in somatotopic map so SS cortex and map are rewired

Front 379

what happens when nerves dev independently of peripheral input

Back 379

phantom limb

Front 380

what could cause tickle itch and sex?

Back 380

carried by small diameter myelinated and unmyelinated fibers
STT, SRT, VTT
could be due to pattern vs population coding
or labeled line primary afferents selective for category of sensation

Front 381

how does brain respond differently than other organs?

Back 381

localization: site of lesion makes a big difference
confined to a fixed volume/space
BBB
selective vulnerability
autoregulation - brain can control its own blood flow in response to oxygen and glucose levels
no lymphatic drainage
glial - not fibrotic sars
-DOES NOT make fibrotic scars in response to lesions/undergoes glial proliferation

Front 382

cause gliosis and involved in Alzheimer's type II change

Back 382

astrocytes

Front 383

proliferation of astrocytes in response to injury (nonspecific)

Back 383

gliosis

Front 384

Alzheimer's type II changes

Back 384

change in astrocytes
has nothing to do with Alzheimer's disease
seen in metabolic issues like hepatic encephalopathy - toxic injury to brain

Front 385

losing oligodendrocytes leads to

Back 385

demyelination

Front 386

rod cells, nodules, phagocytosis

Back 386

microglia

Front 387

definition of ICP

Back 387

P > 200 mm water

Front 388

complications of increased intracranial pressure

Back 388

headache
confusion
papilledema

Front 389

what can cause ICP?

Back 389

cerebral edema
tumors
abscesses
hematoma
main adverse effect: herniation

Front 390

noncommunicating hydrocephalus

Back 390

obstruction of ventricular system

ex: pineal tumor

Front 391

communicating

Back 391

not due to obstruction of ventricular system
due to impaired reabsorption of CSF at arachnoid villi (scarring)
or meningeal scarring after meningitis --> subarachnoid hemorrhage
fibrosis occlude foramen of magendie

Front 392

overproduction of CSF by choroid plexus is what kind of hydrocephalus
due to benign tumor choroid plexus that makes too much CSF

Back 392

communicating

Front 393

bulging tense soft spot on top of infants
large prominent veins in scalp
may not be able to look downward with white of eyes (setting sun sign)
irritability/lethargy
high pitched cry
seizures
vomiting
papilledema

Back 393

hydrocephalus in babies

Front 394

anterior horn of lateral ventricles rounded tip instead of sharp point

Back 394

hydrocephalus

Front 395

increased ICP with headache
signs of dementia, parkinsonian gait, memory loss,

Back 395

hydrocephalus

Front 396

brain pushing out during craniotomy
ventricular dilation due to cerebral atrophy
dilatation of ventricles bc brain is shrinking

Back 396

hydrocephalus ex vacuo
ex of communicating hydrocephalus

Front 397

anterior cerebral artery infarct
cingulated gyrus pushes under falx

Back 397

subfalcine herniation

Front 398

oculomotor compression
posterior cerebral artery infarct
midline midbrain/pontine (duret) hemorrhages
uncus gets pushed under tentorium

Back 398

transtentorial herniation

Front 399

compression of medulla/respiratory centers

Back 399

tonsillar

Front 400

1-5 per 1000 live births
replaced by area cerbrovasculosa
posterior fossa spared
frog babies
missing skull and brain
forebrain is replaced by tangled up mass of blood vessels and neuropil

Back 400

anencephaly

Front 401

forebrain replaced by tangled mass of blood vessels and neuropil

Back 401

area cerebrovasculosa

Front 402

opening in occipital or posterior fossa

Back 402

encephalocele

Front 403

meningocele and meningomyelocele are examples of

Back 403

spina bifida

Front 404

opening to meninges or to spinal cord

Back 404

spina bifida

Front 405

what is the least significant form of spina bifida?

Back 405

spina bifida occulta

Front 406

open from head to lower spain - worst neural tube defect

Back 406

craniorachischesis

Front 407

how do you test for neural tube defect?

Back 407

look for elevated alpha-fetoprotein

Front 408

prenatal folate deficiency increases risk of what?

Back 408

having a baby with neural tube defect

Front 409

small posterior fossa, cerebellar vermis displace down through foramen magnum, hydrocephalus, lumbar meningomyelocele

Back 409

arnold-chiari malformation

Front 410

posterior fossa is enlarged
4th ventricle is a cystic area
posterior vermis is not there (rudimentary)

Back 410

dandy-walker malformation

Front 411

hydromyelia

Back 411

dilated central canal (patent and dilated, normally should be completely collapsed)

Front 412

syringomyelia

Back 412

cleftlike cavity of inner portion of cervical cord or brainstem
little cavities in cervical SC
usually due to a space occupying lesion, arnold-chiari malformation, trauma

Front 413

incomplete midline separation, midline facial anomalies (cyclopia)
trisomy 13
arrhinencephaly

Back 413

holoprosencephaly

Front 414

what is arrhinencephaly

Back 414

lack of olfactory apparatus

Front 415

petau syndrome

Back 415

trisomy 13

Front 416

sometimes corpus callosum fails to form in agenesis

Back 416

holoprosencephaly
spectrum of retardation (normal to severely mentally retarded)

Front 417

• Premature babies often have
• Hemorrhage in the periventricular brain parenchyma, particularly in germinal matrix where neurons are growing before the move out the cortex
• Germinal matrix very prone to hemorrhage
• Right under ependymal cells so if it hemorrhages it is easy to break through into the CSF (reason neonatologists call intraventricular hemorrhage)

Back 417

intraparenchymal hemorrhage

Front 418

infarcts with mineralization, prematurity, extensive cases multicystic encephalopathy
• Also happens in premature babies
• Infarcts in brain that tend to calcify
• Sometimes there will be lots of these and they become cystic which results in multicystic encephalopathy

Back 418

periventricular leukomalacia

Front 419

- deep sulci in cortex (ulegyria), basal ganglia & thalamus aberrant myelination
• Brings us back to concept of selective vulnerability
• Some neurons are more susceptible to different kinds of injury, especially ischemia, than others
• Neurons on cerebral cortex surface are more resistant to ischemia than deep neurons
• Ulegyria

Back 419

ischemic injury

Front 420

– gyri look like a mushroom, at base of gyrus it looks shrunken up

Back 420

ulegyria

Front 421

elastic biconvex transparent
composed of living cells
highly modified epithelial cells from ectoderm

Back 421

lens

Front 422

lens is low in

Back 422

water 66%

Front 423

lens is high in

Back 423

protein 33%

Front 424

does the lens have blood supply?

Back 424

no and low oxygen

Front 425

what is important in lens?

Back 425

glutathione

Front 426

what does glutathione do?

Back 426

lowers the O2 content

Front 427

what is important in regenerating glutathione?

Back 427

ascorbic acid

Front 428

metabolism in the lens is by

Back 428

anaerobic
glycolysis

Front 429

zonules

Back 429

attach lens to ciliary process for focusing

Front 430

what pathway is important for using high glucose levels and recycling NADPH from HMP shunt?

Back 430

sorbitol

Front 431

what converts glucose to sorbitol?

Back 431

aldose reductase

Front 432

what maintains the low water content in lens?

Back 432

Na+/K+ ATPase

Front 433

what keeps protein from aggregation?

Back 433

glutathione lower O2 content and keeps protein reduced

Front 434

what is a molecular filter for light and reduces chromatic aberration?

Back 434

lens

Front 435

effect of sorbitol on lens

Back 435

diabetic cataracts

Front 436

what does aldose reductase convert galactose to?

Back 436

Galactitol or Dulcitol

Front 437

Can infants or adults metabolize galactose better?

Back 437

adults

Front 438

what enzyme do you need to break down galactose and is only found in trace amount in infant liver

Back 438

UDP-Gal pyrophosphorylase

Front 439

what are 4 kinds of protein found in the lens?

Back 439

alpha-crystallin
beta-crystallin
gamma-crystallin
albuminoid

Front 440

which is more potent? sorbitol or galactitol (dulcitol)

Back 440

dulcitol bc it does not get neutralized to fructose

Front 441

cataract formation causes what types of changes

Back 441

change in permeability of membrane of lens cells
change in physical state of proteins
change in enzymatic properties of lens

Front 442

how much oxygen does the retina have?

Back 442

5x the oxygen content of any other tissue in the body

Front 443

does the retina have a large blood supply?

Back 443

yes
has more membrane than any other tissue

Front 444

how does retina maintain fluidity of retinal membrane?

Back 444

polyunsaturated fatty acids
lots of omega 3s

Front 445

light breaks double bonds of lipids in membrane of retina in presence of O2 to form...

Back 445

free radicals

Front 446

2 superoxides + 2H+ forms

Back 446

peroxide and oxygen

Front 447

superoxide + hydrogen peroxide forms

Back 447

peroxidation and cleavage of unsaturated fatty acids --> destroys eye with Iron (fe3+)

Front 448

what can break down hydrogen peroxide?

Back 448

catalase

Front 449

hydrogen peroxide + 2GSH is catalyzed by what to form GSSG and water?

Back 449

glutathione peroxidase
need selenium

Front 450

lens protects against what wavelengths?

Back 450

315-400 nm light

Front 451

UV light is blocked by what in the eye?

Back 451

cornea and lens

Front 452

only wavelengths that gets to retina

Back 452

400-1400 nm

Front 453

what protects against 400-500 nm light in macule?

Back 453

carotinoids

Front 454

what helps protect against light damage?

Back 454

pigment in the iris (not good to have blue eyes)

Front 455

what absorbs almost all of damaging UV?

Back 455

cornea

Front 456

does retinal pigment epithelium protect against light damage?

Back 456

no not much
probably used to block light scatter

Front 457

what are the bodyguards tha help arrest harmful free radicals?

Back 457

vit E, C, beta-carotene

others:
superoxide dismutase
glutathione, taurine
chromium
selenium

Front 458

what kinds of cells in the eye are analogous to neuoglia of CNS?

Back 458

Muller - have long cytoplasmic processes which embrace encircle retinal neurons

Front 459

what type of metabolism does the retina use?

Back 459

glycolysis
krebs cycle

Front 460

what has 5x more glutamine synthetase?

Back 460

retina in the muller cells

remember that glutamate is toxic to retina if not metabolized

Front 461

what has a high requirement for protein and phospholipid for membrane synthesis?

Back 461

retina

Front 462

light converts 11-cis retinal to

Back 462

all trans forms

Front 463

inner segment of rod photoreceptors contain

Back 463

prominent golgi apparatus and many mitochondria

Front 464

outer segment contains

Back 464

stack of flattened membrane discs, incorporate rhodopsin
membranous discs are continuously shed from end of rod
phagocytosed by pigmented epith cells

Front 465

phototransduction-steps

Back 465

light converts rhodopsin to a fom that activates transducin (GDP-GTP)
transducin activates phosphodiesterase (PDE) by Talpha subunit
PDE decreases cGMP
cGMP increases Na+ inflow in photoreceptor cell
this light is an off signal

Front 466

ratio of proteins in eye

Back 466

900 rhodopsin/ 1 PDE/ 2 cGMP

Front 467

1 rhodopsin activates:

Back 467

2000 PDE --> Hydrolyzes 2.5 million cGMP/sec

rhodopsin is embedded in disc membrane

Front 468

does the lens last a lifetime?

Back 468

yes
no turnover, but slow addition of cells at periphery
transplantable

Front 469

anterior epithelium of lens is made up of

Back 469

single layer of cuboidal cells

Front 470

mature lens fibers are greatly elongated specialized epithelial cells, prism-shaped, los nuclei as they age and squeezed toward midline. new lens fibers form from lens cells at:

Back 470

equator
compress central cells

Front 471

what has a vascular core surrounded by double layer of pigmented epithelium?

Back 471

ciliary processes

Front 472

what does the ciliary processes secrete?

Back 472

aqueous humor

Front 473

what serves as the junction between ciliary body and choroid?

Back 473

ora serrata

Front 474

vascular and pigmented
helps provide nutrition to the retina and absorbs scattered light

Back 474

choroid

Front 475

what is derived from the outer layer of embryonic optic cup?

Back 475

pigment epithelium

Front 476

what are the functions of the pigment epithelium?

Back 476

absorbs scattered light rays
phagocytosis of worn out discs
stores and releases vitamin A to photoreceptors

Front 477

where are receptor potentials generated in the eye?

Back 477

rods and cones

Front 478

specialized desmosome-like junctions between glial cells of
retina (Muller cells) and photoreceptors. Appears like line at L.M. level.

Back 478

external limiting membrane

Front 479

what are horizontal cells?

Back 479

association neurons (interneurons) involved in local processing of visual information in retina

Front 480

what kind of cells are found in the outer plexiform layer?

Back 480

bipolar and horizontal cells

Front 481

what kind of cells are found in the inner nuclear layer?

Back 481

bipolar neurons

Front 482

what kind of potential do bipolar cells generate?

Back 482

slow graded potential

Front 483

what kinds of cells are found in the inner plexiform cells

Back 483

amacrine, bipolar, ganglion

Front 484

nerve fiber layer

Back 484

unmyelinated axons of retinal ganglion cells that follow curvature of retina
become myelinated optic nerve outside retina after existing lamina cribosa

Front 485

what do ganglion cells generate?

Back 485

APs

Front 486

expanded ends of muller glial cells and BM directly adjacent to vitreous
appears like line with light microscopy

Back 486

internal limiting membrane

Front 487

where is the blind spot in the eye?

Back 487

optic disc

Front 488

is cis stable or trans rhodopsin?

Back 488

cis is more stable
trans is unstable and dissociates from opsin --> increase outward conduction in calcium --> reduce membrane permeability to Na --> hyperpolarization/generation of receptor potential which leads to production of further electrical signals to brain

Front 489

Two transmitters of primary afferent fibers.

Back 489

Glutamate
Substance P

Front 490

olfactory sensation is processed virtually entirely by components of:

Back 490

limbic system

Front 491

Lesions of the trigeminal nuclei produce this laterality of facial sensory deficits.

Back 491

ipsilateral

Front 492

Level of brainstem rostral to which all sensations from the face are represented contralaterally?

Back 492

mid pons

Front 493

common cause of caloric testing reveals both L and R eyes cannot adduct

Back 493

bilateral MLF
cause of this: MS

Front 494

General (NOT TASTE!) somatic sensation from the oral & nasal cavities is carried by these CNs and this pontomedullary nucleus.

Back 494

CN V, IX, X

Front 495

Deficits, laterality and body region involved with a lesion of the anterior white commisure of the SC.

Back 495

CAN be cape-like if it’s in the cervical cord.
Lesion lower→ bilateral band of loss of sensation 2-3 segments below.

Front 496

Ear that will hear the loudest song if you plug your L ear & place a tuning fork on your forehead midline.

Back 496

left ear

Front 497

CN level to which CNS depression must descend (be present) if the Doll’s Eyes (oculocephalic reflex) is absent

Back 497

a. CN VI or below
i. You have to get at least to VI bc you have to get to MLF. If you go further, it’s even worse…
ii. You have to get III & VI to get the eyes locked in the head
iii. Btw 3 and 6 would be equivalent to an MLF lesion.

Front 498

Labyrinth pathology accounting for the following: slow phase of nystagmus (active, physiologically driven movement), past-pointing and a tendency to fall to the R:

Back 498

irritative lesion on LEFT
destructive lesion on RIGHT
if my eyes are HYPOACTIVE on the R, i would look R

Front 499

Descending inhibition of nociception utilizes these THREE transmitters @ a minimum:

Back 499

NE
5-HT
opiods

Front 500

most caudal location of a lesion producing decreased pain/ temperature sensation over the L face and decreased pain/ temperature sensation on the R side of the body, below the head.

Back 500

left caudal medulla
aka lateral medullary syndrome

Front 501

Infarct of this vessel can produce deficits in taste from the tongue, palate & epiglottis.

Back 501

PICA and vertebral artery
where solitary nucleus is

Front 502

nociception, thermal sense & perception of pain from the body are conveyed by this system that is comprised of these tracts:

Back 502

AL: SMT, STT, SRT

Front 503

Specific area of brainstem involved w sound localization through analyzing time differences.

Back 503

superior olive
medial (time)
lateral (intensity)

Front 504

Lesions of trigeminal nuclei produce this laterality of facial sensory deficits:

Back 504

ipsilateral

Front 505

CN V nuclei involved in relaying two-point discrim & vibr sense from the face

Back 505

Chief or principal sensory
rostral spinal (2/3)

Front 506

location of lesion causing CN deficits and deficits of sensory and / or motor modalities from the body: (where do long tracts cross CN nuclei)

Back 506

brainstem (medulla and pons)

Front 507

19. CN V sensory nucleus involved exclusively in proprioception and reflex control of chewing:

Back 507

mesencephalic nucleus of V

Front 508

Internal structures that amplify sounds by 30-40 db

Back 508

ossicles

Front 509

brainstem nucleus & thalamic nucleus responsible for conveying taste sensation

Back 509

solitary nucleus of V
VPM

Front 510

CNs responsible for conveying taste

Back 510

7, 9, 10

Front 511

possibly symptoms assoc with acoustic neuroma (schwannoma)

Back 511

a. tinnitus,
b. ipsilateral deficits in corneal reflex,
c. spontaneous facial pain with sensory loss,
d. ipsilateral facial weakness and decreased taste,
e. deafness,
f. loss of equilib

Front 512

dynamic function of vestibular function

Back 512

VOR eye movements

Front 513

tract utilized and effect exerted to maintain balance when pushed or shoved while studying

Back 513

lateral vestibulospinal tract & facilitation of motor neurons of leg extensors (VSR)

Front 514

main blood supply to pons at level of CN6 and 7

Back 514

circumferential br of basilar
AICA

Front 515

infarct of this vessel leads to alternating hemianesthesia
loss of pain and themal sense from one side of face and opposite side of body, vertigo, nystagmus, and ipsilateral Horner's syndrome

Back 515

vertebral artery and PICA (lateral medullary syndrome)

Front 516

main blood supply to all SS tracts at the level of the midbrain

Back 516

PCA

Front 517

condition and pathology that causes sensory loss in hands or feet in a glove or stocking pattern

Back 517

diabetic neuropathy

Front 518

lesion of CN VI nucleus and/or surrounding reticular formation produces this deficit

Back 518

ipsilateral gaze paralysis

Front 519

hyperalgesia to extent that non-noxious stimuli are painful

Back 519

allodynia

Front 520

lesion below R calcarine fissure results in visual field deficit

Back 520

Left superior quadrantanopia
pie in the sky

Front 521

visual field defect caused by lesion of R caudal part of temporal lobe

Back 521

L superior quadrantanopia (meyer's loope)
object recognition will be lost

Front 522

lesion of ascending MLF leads to this visual defect

Back 522

INO internuclear ophthalmoplegia

Front 523

injury-induced local mechanism leading to hyperalgesia originating at peripheral receptors

Back 523

inflammation caused by release of local chemical mediators

Front 524

lesion of this assocn cortical region can produce asterognosis & agraphesthesia

Back 524

5 & 7 parietal cortex

Front 525

right side bilterally is wiped out

Back 525

R homonymous hemianopia

Front 526

cause of the following: L eye rotated down and out at rest & dilated L pupil

Back 526

lesion of CN3, including edinger-westphal

Front 527

3 signs of horner's syndrome

Back 527

ptosis
miosis
anhydrosis

Front 528

41. lesion that causes loss of pain and temp sense from L body and loss of proprioception, fine touch and vibratory sense on the R body lacking face involvement (include laterality)

Back 528

brown-sequard

Front 529

recently discovered and cloned receptor family that fulfills criteria of a legit polymodal nociceptor at “Free nerve endings.”

Back 529

TRP

Front 530

possible mechanism contributing to central sensitization of the dorsal horn of the spinal cord:

Back 530

a. rearranegement of A-β fibers to nocicceptive relay cells and/or transcriptionally altered secondary relay neurons (RE-WIRING)

Front 531

pituitary tumor can produce this visual field defect

Back 531

bitemporal hemianopsia
optic chiasm is squished

Front 532

accommodation triad

Back 532

convergence
pupillary constriction
ciliary muscle contraction

Front 533

eye movement deficits seen with destruction of L cerebral hemisphere anterior to central sulcus

Back 533

frontal fields, no saccadias
b. lessened ability to excute voluntary R saccades (conj gaze

Front 534

lesion of this causes ipsilateral complete sensory (and motor) loss in one dermatome

Back 534

DRG or spinal nerve lesion

Front 535

site of lesion and vessels causing complete L facial paralysis and inability to abduct eye

Back 535

MCA and AICA

Front 536

tumor growing in this structure causes parinaud's syndrome

Back 536

paralysis of upward vertical gaze
pineal gland tumor compresses on tectum

Front 537

vessel supplying region of sensory and motor cortex that maps leg and foot

Back 537

ACA

Front 538

51. arteries supplying the ventral basal thalamus

Back 538

thalamoperforator and thalamageniculate arteries of PCA

Front 539

52. site of a focal lesion and vessels most likely involved that explains the following: complete R side deficits to all somatic sensation and upper motor neuron heiparesis on the entire R side, no visual deficits & no sensory neglect.

Back 539

Posterior limb of the L internal capsule; lenticulostriate branches of the MCA and/or anterior choroidal artery

Front 540

the lever system of ossicles causes

Back 540

increase in force
decrease in amplitude

Front 541

tensor tympani inserts into

Back 541

malleus
innervated by mandibular division of V

Front 542

stapedius inserts onto

Back 542

stapes
innervated by facial

Front 543

eustachian tube connects what to what?

Back 543

middle ear to nasopharynx
to equalize pressure during yawning or swallowing

Front 544

perilymph

Back 544

high in Na+, low in K+ like CSF

Front 545

endolymph

Back 545

high in K+, low in Na+
hair cells -specialized neuroepithelial mechanoreceptors for audition and vestibular function, located in specialized regions of membranous labryrinth

Front 546

invagination of ectoderm from hindbrain pinches off and forms what?

Back 546

otocyst

Front 547

otocyst becomes

Back 547

membranous labyrinth to form bony labyrinth

Front 548

what forms bony labyrinth?

Back 548

mesoderm

Front 549

tectorial membran is a stiff gelatinous structure attached to:

Back 549

limbus - a connective tissue shelf extending from spiral lamina

Front 550

pilar (tunnel) cells are

Back 550

specialized support cells around tunnel of corti
tightly attached to BM
contain tonofibrils (large microtubules) that make rigif triangular structure which acts as a fulcrum of BM

Front 551

a gelatinous mass (glycosaminoglycans) in which the stereocilia are embedded.
Cupola is tethered to roof of ampulla.

Back 551

cupula

Front 552

elevated ridge of highly specialized
epithelial tissue inside ampulla of membranous semicircular duct, is the sensory organ for
detection of rotational motion (angular acceleration).

Back 552

crist ampullaris

Front 553

role of melanin in choroid

Back 553

revents light rays that have passed through the rods and cones from bouncing back onto these cells

Front 554

retina receives its blood supply primarily from branches of

Back 554

ophthalmic artery
which comes from internal carotid

Front 555

strong electrical potential will record AP with what types of nerve fibers?

Back 555

Abeta, delta, C

Front 556

weak electrical AP in what fiber?

Back 556

Abeta only
big nerve fibers have lowest threshold

Front 557

tap, light pressure, movement

Back 557

Abeta peak only

Front 558

heavy pressure

Back 558

Abeta and A delta

Front 559

pinch prick

Back 559

Abeta C

Front 560

Hot, cold

Back 560

A delta and C

Front 561

Strong electrical with pressure cuff

Back 561

Adelta and C

Front 562

strong electrical with local anesthetic

Back 562

Abeta peak only

Front 563

fast conduction fibers

Back 563

large diameter
heavily myelinated
Abeta

Front 564

intermediate conduction fibers

Back 564

smaller diameter
lightly myelinated fibers

Front 565

slow conduction fibers

Back 565

smallest diameter
unmyelinated C

Front 566

ischemia preferentially blocks

Back 566

large myelinated fibers

Front 567

local anesthetics first block

Back 567

unmyelinated fibers then lightly myelinated then heavily myelinated (myelination protects against anesthetic)

Front 568

large diameter fibers subserve

Back 568

reflex activities
fast discriminative sensations
well localized and characterized
high quality and fidelity

Front 569

small diameter fibers subserve

Back 569

slow and more diffuse sensation
can be poorly localized and characterized
lower quality and fidelity

Front 570

free nerve endings include

Back 570

thermal receptors
pain receptors

Front 571

specialized cells that directly affect afferent nerve terminal:

Back 571

touch receptors such as merkel's, meissner's pacinian
hair follicles
golgi tendon organ

Front 572

exteroceptors

Back 572

localized on external surface
sense ambient environment

Front 573

proprioceptors

Back 573

mainly in muscles, tendons, joints
signal position and movement of limbs by sensing muscle length

Front 574

interoceptors

Back 574

localized to internal organs and blood vessels
sense visceral and internal environment

Front 575

mechanoreceptors

Back 575

physical change or movement
fast and slow adapting

Front 576

thermoreceptors

Back 576

warm cold slowly adapting

Front 577

nociceptors

Back 577

mechanical nociceptors
thermal nociceptors
polymodal nociceptors
slowly adapting

Front 578

ex of proprioceptors

Back 578

muscle spindles
golgie tendon organs
joint receptors
rapidly adapting
generally out of realm of conscious awareness
can be perceived consciously
important modality to assess neurologic deficits

Front 579

are receptor potentials grade?

Back 579

yes
amplitude is proportional to stimulus strength

Front 580

receptor potentials trigger what in afferent nerve if threshold is exceeded?

Back 580

APs

Front 581

frequency of action potential firing is proportional to what?

Back 581

the magnitude of receptor potential
larger receptor potential
faster the neuron will fire

Front 582

neural code

Back 582

pattern, frequency, and duration of groups of APs
encodes intensity and duration

Front 583

adequate stimulus

Back 583

type of stimulus energy to reach lowest threshold

Front 584

slow adapting

Back 584

on response followed by sustained response
A delta and C fibers
signals location and continued presence of stimuli

Front 585

nociceptors can show afterdischarge

Back 585

continued generation of APs after cessation of nociceptive stimulus

Front 586

receptor potential and frequency of firing is related how?

Back 586

proportional
stronger stimuli excite more receptors and afferents = recruitment of sensory units

Front 587

location coding depends on 3 principals

Back 587

receptive fields of peripheral afferents
dermatomes
somatotopic organization of pathways

Front 588

what is peripheral receptive field

Back 588

area of body that contains receptor ending of a single afferent fiber and stimulated with adequate stimulus for receptor endings
activates afferent fiber

Front 589

receptive fields-can be exitatory or inhibitory with respect to projection neurons?

Back 589

yes

Front 590

surround inhibition in CNS

Back 590

sharpens contrast of stimulus signals for better intensity and location coding
sensory systems function as edge detectors and contrast comparators
change in neural activity pattern = increased contrast

Front 591

do receptive fields differ in size at different parts of body?

Back 591

yes
small on hands and face
large on back and legs and arms

Front 592

spatial discrimination ability is best where

Back 592

small receptive fields like hands

Front 593

2 point discrimination

Back 593

on hands/lips are small -mm
back and legs --cm

Front 594

occlusive stroke caused by

Back 594

thrombosis
atherosclerosis

Front 595

hemorrhagic strokes caused by

Back 595

hypertension
aneurysm

Front 596

excitotoxicity elicits cell death by

Back 596

binding inflammatory cytokines like TGF to receptors in neuronal membrane
loss of neuronal connections to a target and deprivation of trophic support --> cell death

Front 597

necrosis

Back 597

nonphysiological
disrupt homeostasis

Front 598

characteristics of necrosis

Back 598

disrupt cell membrane
influx of Ca2+ ions/water/ionic gradients
mitochondria swell/dysfunction
lysosomal enzymes activated
cell swells and lyses
denatured proteins, DNA --> local inflammatory response

Front 599

apoptosis

Back 599

programmed cell death is death with integrity
function in normal dev and homeostasis

Front 600

features of apoptosis

Back 600

req new RNA and protein synthesis
req activity of specific genes
involve endonucleolytic cleavage and cellular DNA fragmentation
membrane blebbing
intracellular compaction of nucleus and deposit electron dense chromatin
pinch off membrane bound apoptotic bodies
internal/external membranes are preserved

Front 601

glial scarring is accompanied by increased secretion of:

Back 601

TGF, FGF, TNFalpha, interleukins, interferon gamma, IGF1

Front 602

excitotoxicity and apoptosis can be triggered by

Back 602

perturbation of intracellular Ca homeostasis
dysregulation of free radical metabolism

Front 603

Is there evidence showing ischemia can lead to excitotoxicity?

Back 603

Conc’s of Glu and Aspartate (Asp) in the synaptic cleft around neurons increase during ischemia
Microinjection of Glu receptor antagonists in experimental animals protect neurons.
Presumably reduced supply of oxygen and glucose during ischemia elevates extracellular Glu levels by slowing the energy-dependent removal of Glu at synapses.

Front 604

blocking glutamate should protect neurons, but it hasnt worked well in clinical trials. why?

Back 604

substantial excitotoxic injury occurs quite soon after ischemia prior to typical treatment
excitotoxcity only one of several mechanisms by which ischemia damages neurons.