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neurology > Block 2 > Flashcards

Block 2 Flashcards

1
Q

at what day does gastrulation occur

A

12

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2
Q

at what day does neurulation occur, what signifies the start

A

16
neuroectoderm

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3
Q

at what day does the neural tube close

A

21-28
day 21= anterior pore
day 28= posterior pore

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4
Q

what are the 10 derivatives of the neural crest

A

mesencephalic nucleus of midbrain
melanocytes
meninges (pia and arachnoid)

cranial nerve ganglion
autonomic ganglia cells
schwann cells
chromaffin cells
adrenal medullary cells
dorsal root ganglion
enteric neurons

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5
Q

what are the divisions at the 3 vesicle stage

A

rhombencephalon (hindbrain)
mesencephalon (midbrain)
prosencephalon (forebrain)

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6
Q

what are the 5 divisions at the 5 vesicle stage

A

rhombencephalon forms metencephalon and mylencephalon
mesencephalon remains as mesencephalon
prosencephalon forms diencephalon and telencephalon

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7
Q

what are the 2 genes involved in transcription of induction and suppressor factors in early neurogenesis of the CNS

A

BMP (bone morphogenic protein)
SHH (sonic hedgehog)

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8
Q

SHH is involved in what function

A

motor

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9
Q

what forms from the telencephalon

A

cerebral hemispheres
basal ganglia

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10
Q

what forms from the diencephalon

A

thalamus
pineal gland
hypothalamus
neurohypophysis
retina

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11
Q

what forms from the mesencephalon

A

midbrain

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12
Q

what forms from the metencephalon

A

pons
cerebellum

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13
Q

what forms from the myelencephalon

A

medulla

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14
Q

what are 2 aspects of the developing neural tube

A

alar plate
basal plate

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15
Q

is the alar or basal plate the dorsal vs ventral aspect of the neural tube

A

alar plate= dorsal
basal plate= ventral

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16
Q

what causes induction of the alar plate vs the basal plate

A

alar plate is induced by BMP (bone morphogenic proteins)
basal plate is induced by SHH (sonic hedgehog)

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17
Q

how do the alar and basal plate differ in the types of neurons they form

A

alar forms sensory tract neurons (alar plate is dorsal aspect)
basal forms motor and preganglionic autonomic neurons (basal is ventral aspect)

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18
Q

what divides the alar and basal plates

A

sulcus limitans

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19
Q

what does the cerebellum develop from

A

rhombic limb

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20
Q

at what time does the cerebellum develop

A

week 5-6

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21
Q

the central part of the rhombic limb becomes the __
the lateral parts are the __

A

central- vermis
lateral- cerebellar hemispheres

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22
Q

when does growth from the telencephalon occur

A

week 5

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23
Q

the diencephalon is organized into a dorsal and ventral part. the dorsal part forms the __ while the ventral part forms the __

A

dorsal= thalamus
ventral= hypothalamus

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24
Q

what are the 3 major components of the basal ganglia in the telencephalon

A

caudate nucleus
putamen
globus palidus

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25
Q

what are the 2 components of the basal ganglia which are found in the diencephalon or midbrain

A

substantia nigra
subthalamus

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26
Q

the limbic system functions for __ and __

A

emotion and memory

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27
Q

most of the components of the limbic system come from what

A

telencephalic vesicle neurons

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28
Q

the lateral ventricles come from what embryonic structure

A

telencephalic hemisphere

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29
Q

the third ventricle comes from what embryonic structure

A

diencephalon

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30
Q

the fourth ventricle comes from what embryonic structure

A

rhombencephalon

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31
Q

when does myelination of the spinal cord begin

A

4th month (week 16)

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32
Q

when does myelination of the brain begin

A

6th month

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33
Q

when does myelination of the corticospinal tract begin

A

6th months post-natal

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34
Q

when is myelination of the spinal cord complete

A

it continues until at least 2.5-3 years

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35
Q

when does myelination of the brian complete

A

it may continue up to age 20-25 in the frontal lobes

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36
Q

what is the cause of a Babinski reflex present in those under age 2.5

A

incomplete myelination of corticospinal tracts

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37
Q

what is the mechanism of anencephaly

A

failure of anterior neuropore closure between day 25-28

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38
Q

what causes anencephaly

A

folic acid deficiency

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39
Q

what is the mechanism of spina bifida

A

failure of posterior neuropore closure

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40
Q

what is the characteristic of spina bifida occulta

A

benign

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41
Q

what is the characteristic of spina bifida cystica meningocele

A

protrusion of meninges

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42
Q

what is the characteristic of spina bifida meningomyelocele

A

protrusion of meninges and nerves

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43
Q

what is the characteristic of spina bifida myelocele

A

protrusion of nerves

*this is the worst type of spina bifida

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44
Q

what is the mechanism of encephalocele

A

failure in processes associated with closure of anterior neuropore

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45
Q

what are the 2 main causes of encephlocele

A

folic acid deficiency
teratogens

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46
Q

what is a main concern of hemorrhage of the placenta during the second trimester

A

underdevelopment of part of the cerebral cortex
(germinal matrix hemorrhage)

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47
Q

what causes gray matter heterotopia

A

failure of cortical cells to migrate to their final position of the cortex

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48
Q

what causes gray matter heterotopia

A

interruption in germinal matrix, especially during 2nd trimester

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49
Q

what causes lissencephaly

A

failure of cortical cells to migrate to their final position in the germinal matrix

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50
Q

what is a common characteristic of lissencephaly

A

smooth brain lacking gyri

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51
Q

Arnold Chiari malformation is characterized by herniation of __ in type
I= __
2=__
3/4=__

A

1= cerebellar tonsil
2= cerebellum
3= lower brain stem through foramen magnum

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52
Q

Dandy Walker syndrome is visible by what

A

complete or partial cerebellar agenesis, often the vermis

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53
Q

what are the symptoms of Dandy Walker syndrome

A

dilated 4th ventricle
hydrocephalus
small vermis (absent or small)

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54
Q

syringomyelia is characterized by what

A

abnormal enlargement of the central canal of the spinal cord, often damaging fibers of the spinothalamic tract

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55
Q

what are the 3 broad categories of cerebral palsy

A

spastic
ataxic
athetoid/dyskinetic

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56
Q

what is the most common type of cerebral palsy

A

spastic

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57
Q

what type of damage is common in those with spastic cerebral palsy

A

upper motor neuron lesions and GABAnergic receptor dysfunction in the spine

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58
Q

what type of damage is common in those with ataxic (intension/action tremors) cerebral palsy

A

cerebellar

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59
Q

what type of damage is common in those with athetoid (dyskinetic) cerebral palsy

A

damage to basal ganglia or just the substantia nigra

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60
Q

what are the 2 classes of athetoid (dyskinetic) cerebral palsy

A

choreoathetoid
dystonic

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61
Q

how do choreoathetoid and dystonic cerebral palsy differ

A

choreoathetoid- involuntary movements in the face and extremities
dystonic- strong, slow contractions, whole body or local

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62
Q

how does ATP act as an inflammatory chemical

A

ATP activates peripheral nociceptors, signaling the presence of inflamed tissue, producing pain

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63
Q

how do neutrophils act as an inflammatory chemical

A

they synthesize COX-2 which metabolizes arachidonic acid into prostaglandins and cytokines

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64
Q

how does prostaglandin PgE2 act as an inflammatory chemical

A

it blocks K+ efflux from nociceptors causing additional depolarization and altering pain sensitivity by increasing the responsiveness of peripheral nociceptors

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65
Q

how do nerve growth receptors act as inflammatory chemicals

A

they promote structural reorganization and alteration in the patterns of nerve connections

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66
Q

the neospinothalamic tract is involved in what aspect of pain

A

direct consciousness

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67
Q

the neospinothalamic tract directs to the __

A

VPL

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68
Q

the paleospinothalamic tract is involved in what aspect of pain

A

indirect arousal/emotional impact of pain

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69
Q

there are 3 pathways of the paleothalamic tract. these include…

A
  1. general paleothalamic to cingulate gyrus
  2. spinoreticular to cerebral cortex
  3. spinotectal/spinomesencephalic
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70
Q

what is analgesia

A

insensibility to pain without loss of consciousness

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71
Q

what is anesthesia

A

insensitivity to pain with induced loss of consciousness

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72
Q

what is paresthesia

A

numbness (pins and needles)

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73
Q

what is hyperalgesia/hyperesthesia

A

enhanced sensation to pain due to exposure of inflammatory factors

*prostaglandin E2 can cause hyperalgesia

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74
Q

what is allodynia

A

feeling of pain sensation following a non-painful stimulus

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75
Q

what is neuralgia

A

neuropathic pain not related to activation of pain receptors

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76
Q

what is phantom pain

A

pain sensation felt in an amputated body area due to over activity of a second order pain mediating neuron

77
Q

what is thalamic pain syndrome (Dejerine-Rousy)

A

pain caused by vascular lesion to VPL of the thalamus

78
Q

what is trigeminal neuralgia (Tic douloureux)

A

neuralgia of the areas innervated by CNV (trigeminal)

79
Q

trigeminal neuralgia is associated with compression of the trigeminal nerve root by what artery

A

superior cerebellar artery

80
Q

what are 2 main treatments for trigeminal neuralgia

A

carbamazepine (stabilizes closed Na+)
phenytoin (blocks Na+)

81
Q

if there is a lesion in the grey matter, will there be loss only at the site of the lesion or at the site and below

A

only at site of lesion

82
Q

if there is a lesion in the white matter, will there be loss only at the site of the lesion or at the site and below

A

at site of lesion and below

83
Q

what is contained in the lateral horn

A

preganglionic sympathetic autonomics

84
Q

in what vertebrae segments are preganglionic sympathetic autonomics located

A

T1-L2

85
Q

alpha motor neurons supply __
gamma motor neurons supply __

A

alpha= skeletal muscle
gamma= muscle spindles

86
Q

what are the 2 branches of the motor division of the PNS

A

autonomic
somatic

87
Q

what are the 2 classes of receptors of the autonomic nervous system

A

cholinergic
adrenergic

88
Q

cholinergic receptors of the autonomic nervous system can be classified as __ or __

A

nicotinic
muscarinic

89
Q

nicotinic cholinergic receptors use __
muscarinic cholinergic receptors use __

(GPCR vs ligand gated)

A

nicotinic= ligand gated ion channel
muscarinic= GPCR

90
Q

nicotinic ACh receptors are found where

A

neuromuscular junction
preganglionic synapses
adrenal medulla
throughout CNS

91
Q

what are the 2 classes of nicotinic receptors

A

N1/Nm at neuromuscular junction
N2/Nn at autonomic ganglia, CNS, and adrenal medulla

92
Q

does epinephrine bind to alpha or beta adrenergic receptors with higher affinity

A

beta

93
Q

does norepinephrine bind to alpha or beta adrenergic receptors with higher affinity

A

alpha1>alpha2>beta1

94
Q

does epinephrine or norepinephrine cause a greater response at beta 2 nicotinic receptors

A

epinephrine

95
Q

which adrenergic receptor type acts as an autoreceptor (negative feedback system)

A

alpha2

96
Q

what are beta 1 adrenergic receptors responsible for

A

increased heart contractility/CO/HR
increased renin release through juxtaglomerular cells

97
Q

alpha 1 and beta 1 adrenergic receptors are mainly __ responses
alpha 2 and beta 2 adrenergic receptors are mainly __ responses

A

1= excitatory
2= inhibitory

98
Q

does the adrenal medulla release more epinephrine or norepinephrine

A

80% epinephrine
20% norepinephrine

99
Q

activity of what hormones contributes to sympathetic tone during waking hours

A

adrenal medullary (high cortisol at night, high adrenaline during the day)

100
Q

preganglionic neurons of the parasympathetic nervous system comprise cell bodies of cranial nerves __ which are all located in the brain stem

A

3, 7, 9, 10

101
Q

parotid gland surgery can result in damage to what nerve

A

facial (CN 7)

102
Q

what are the 2 parasympathetic preganglionic neurons of cranial nerve X

A

dorsal motor nucleus (viscera of lungs and abdomen)
nucleus ambiguus (muscles of pharynx, larynx, heart)

103
Q

are pelvic splanchnic nerves sympathetic or parasympathetic

A

parasympathetic

104
Q

what is the sympathetic receptor found in the eyes, what is the response

A

alpha1
pupil dilation (mydriasis

105
Q

what is the sympathetic receptor found in the vascular smooth muscle
what is the response

A

alpha1 with vasoconstriction>beta1 with vasodilation

106
Q

what is the sympathetic receptor found on the sweat glands
what is the response

A

acetylcholine onto M3

107
Q

what is the sympathetic receptor found on myocardiocytes
what is the response

A

beta1
increase contractility, increase HR

108
Q

what is the sympathetic receptor found on the lungs what is the response

A

beta2
increase bronchodilation, decrease secretions

109
Q

what is the sympathetic receptor found in the digestive tract
what is the response

A

alpha2
decrease peristalsis and secretions

110
Q

what is the sympathetic receptor found on the rectum/anal sphincter
what is the response

A

alpha1
contracts internal anal sphincter

111
Q

what is the sympathetic receptor found on the liver
what is the response

A

beta2
increase glycogenolysis

112
Q

what is the sympathetic receptor found on juxtaglomerular cells
what is the response

A

beta1
increase renin release

113
Q

what is the sympathetic receptor found on the detrusor muscle
what is the response

A

beta3>beta2
relaxation, urine storage

114
Q

what is the sympathetic receptor found bladder internal sphincter
what is the response

A

alpha1 contraction
urine storage

115
Q

what is the sympathetic receptor found on the renal medulla
what is the response

A

Ach onto Nn (nicotinic AChR)

116
Q

what is the parasympathetic receptor found on the eyes
what is the response

A

M3
pupil constriction (myosis)

117
Q

what is the parasympathetic receptor found on the vascular endothelium
what is the response

A

M3
vasodilation through production of Nitric Oxiide (NO)

118
Q

what is the parasympathetic receptor found on the myocardiocytes
what is the response

A

M2 (atrium>ventricles)
↓contractility >↓ heart rate

119
Q

what is the parasympathetic receptor found on the lungs
what is the response

A

M3
↓bronchodilation , ↑secretions

120
Q

what is the parasympathetic receptor found on the digestive tract
what is the response

A

M2»>M3
↑peristalsis and secretions

121
Q

what is the parasympathetic receptor found on the detrusor muscle
what is the response

A

M3
contraction, urine voiding

122
Q

what is the parasympathetic receptor found on the bladder internal sphincter
what is the response

A

M3 and M2
relaxation through unknown mechanism

123
Q

what is the sensory presentation of acute ulnar nerve neuropathy

A

numbness/tingling

124
Q

what is the sensory presentation of chronic ulnar nerve neuropathy

A

loss of sensation over the medial 1.5 fingers and palm

125
Q

what is the motor presentation of ulnar nerve neuropathy

A

wasting of interosseous muscles
reduction/loss of abduction and adduction of fingers

126
Q

what are the 2 sites that cubital tunnel syndrome can affect

A

ulnar groove (elbow)
cubital tunnel (forearm)

127
Q

what are the 5 causes of cubital tunnel syndrome

A

trauma
compression/entrapment
diabetes
rheumatoid arthritis
overactivity

128
Q

what are the 5 causes of Guyon’s canal syndrome

A

trauma
compression/entrapment
diabetes
rheumatoid arthritis
overactivity

129
Q

what is the site of Guyon’s canal syndrome

A

Guyon’s canal which is in the wrist

130
Q

if there is severe motor involvement with ulnar nerve neuropathy, what is the management

A

surgery

131
Q

carpal tunnel syndrome is the result of entrapment of what nerve

A

median

132
Q

where is the site of carpal tunnel syndrome

A

wrist at flexor retinaculum

133
Q

what is the sensory presentation of carpal tunnel syndrome

A
  1. intermittent nocturnal paresthesia of thumb, index fingers and palm which awakes patients from sleep
  2. reduced/loss of sensation over lateral 3.5 fingers and palm, and distal tip of thumb, index, middle, and ring fingers

relived by shaking hands

134
Q

what is the motor presentation of carpal tunnel syndrome

A

weakness/wasting of thenar muscles (abductor pollicis brevis)

135
Q

what is the non-surgical management of carpal tunnel syndrome

A

oral or injection glucocorticoid for short term relief

136
Q

what is involved in surgery for carpal tunnel syndrome

A

open carpal tunnel or endoscopic carpal tunnel release

137
Q

what is the sensory presentation of herpes zoster

A

acute lancinating pain and hyperalgesia over skin surface supplied by affected nerve for 3-4 days followed by vesicular herpetic eruptions

muscle wasting and weakness may also occur

138
Q

what is the treatment for herpes zoster

A

oral or topical acyclovir

139
Q

what is the cause of herpes zoster (shingles)

A

varicella zoster virus

140
Q

what is a nerve conduction study

A

a test used to evaluate the function, especially the ability of electrical conduction, of motor and sensory nerves of the body

141
Q

in a nerve conduction study, amplitude decrease is more indicative of __, while velocity decrease is more indicative of __

A

amplitude- nerve damage
velocity- demyelination

142
Q

how does referred pain arise

A

pain arises from deep visceral structures that is felt on the body surface due to convergence of general cutaneous afferents on second order spinothalamic fibers
the pain then either travels on the same fiber or activates neighboring secondary pain fibers

143
Q

what causes CIPA (congenital insensitivity to pain with anhidrosis)

A

absence/mutation in neurotropic tyrosine kinase receptor 1 which usually binds nerve growth factor to help axons reach their targets
(C-fibers)

144
Q

what nerve fiber type is affected by CIPA (congenital insensitivity to pain with anhidrosis)

A

C-fibers

145
Q

how does water soluble olfactory transduction differ from water insoluble

A

soluble- binds to receptors on ciliary surface of bipolar neurons
insoluble- use odorant binding proteins to be transported toward the cilia of bipolar neurons

146
Q

how many receptor types are expressed by each olfactory neuron which get clustered in a single ganglion

A

1

147
Q

what are the primary olfactory sensory neurons

A

bipolar ciliated olfactory cells

148
Q

do olfactory primary neurons regenerate

A

yes

149
Q

what are the main output cells (second order neurons) that become the olfactory tract

A

mitral and tufted cells

150
Q

what is an olfactory transport disorder of olfaction

A

rhinitis

151
Q

what are 3 olfactory sensory disorders of olfaction

A

viral infection
cigarette smoking
fracture of cribriform plate of ethmoid

152
Q

what is a neural disorder of olfaction

A

psychotic disorders

153
Q

the afferent nerves of cranial nerves ___ make up the cell bodies of 1st order neurons of taste

A

CN 7, 9, 10
facial, glossopharyngeal, vagus

154
Q

what taste papillae make up the anterior 2/3 of the tongue

A

filiform
fungiform

155
Q

what taste papillae makes up the posterior 1/3 of the tongue

A

foliate

156
Q

what type of channels do each of the 5 basic tastes use

A

salty and sour use ion channels
sweet, bitter, and umani use G protein

157
Q

what is ageusia

A

loss of taste

158
Q

what is dysgeusia

A

distorted perception of taste

159
Q

what is phantogeusia

A

perception of taste where there is none

160
Q

what are 2 transport disorders of taste

A

Sjogren syndrome (autoimmunity against salivary and lacrimal glands)
xerostomia (dry mouth)

161
Q

what are 2 sensory disorders of taste

A

antibiotics/insecticides
candida

162
Q

what are 3 neural disorders of taste

A

cigarette smoking
Bell’s palsy (CN VII)
stroke

163
Q

what is the most common cause of taste dysfunction

A

medication

164
Q

what is the sequence of initiation of voluntary muscle movement between upper and lower motor neuron and the muscle

A

upper motor neuron innervates a lower motor neuron which innervates the muscle

165
Q

where is the location of upper motor neurons compared to lower motor neurons

A

upper- motor cortex
lower- motor nuclei of cranial nerve and ventral horn of spinal cord

166
Q

alpha motor neurons innervate __
gamma motor neurons innervate __

A

alpha- extrafusal fibers (skeletal muscle)
gamma- intrafusal (muscle spindles) to maintain spindle stretch

167
Q

what 4 symptoms of a lower motor neuron injury

A

muscle fasciculation (twitching)
flaccid paralysis
areflexia
muscle atrophy

168
Q

what is the function of muscle spindles

A

provide sensory afferents about muscle length and stretch

169
Q

what part of the muscle spindle contains contractile muscle fibers and receives input from gamma lower motor neuron efferents

A

ends of the fiber

170
Q

what maintains muscle spindle sensitivity over a muscle length/stretch

A

gamma lower motor neurons

171
Q

what is the function of spinal interneurons

A

integrate cutaneous, proprioceptive, and supraspinal influences in the control of movements, muscle tone, and power through modulating activity of lower motor neurons

172
Q

what are Renshaw cells

A

inhibitory glycinergic neurons in the ventral horn of the spinal cord which mediate reciprocal inhibition of Ia afferent excitation of lower motor neurons

173
Q

what is the cellular activity that causes tetanus

A

inhibition of cells by tetanospasmin

174
Q

what is the autoregulatory method that axons of the lower motor neurons use

A

axons of lower motor neurons have recurrent branches that synapse onto Renshaw cells which then inhibit the same lower motor neurons

175
Q

what is the cellular activity of tetanus

A

the toxin has a high tropism for Renshaw cells and as a result, inhibit their release of glycine and GABA from pre-terminals of inhibitory interneurons associated with lower motor neurons

176
Q

the lateral corticospinal tract is most responsible for control of __ musculature

the anterior corticospinal tract is most responsible for control of __ musculature

A

lateral= appendicular/distal
anterior= axial/proximal

177
Q

what prevents the spread of the toes with the Babinski reflex after around age 2

A

myelination of corticospinal tract

178
Q

what type of neurons make up the caudate and putamen (dorsal striatum)

A

medium spiny neurons

179
Q

what type of neurons make up the globus pallidus (dorsal pallidum)

A

medium aspiny neurons

180
Q

what is the function of the caudate and putamen (dorsal striatum)

A

process converging motor and sensory input

181
Q

what is the function of the globus pallidus (dorsal pallidum)

A

disseminate processed information to the thalamocortical feedback loop

182
Q

pars compacta of the substantia nigra contains what class of neurons

A

dopaminergic

183
Q

pars reticulata contains what class of neurons

A

GABAnergic

184
Q

what is the major neurotransmitter produced by the substantia nigra

A

dopmaine

185
Q

what is the cause of Huntington’s disease

A

increase in CAG repeats in the HTT gene

186
Q

what is the neurological presentation of Huntington’s disease

A

neuronal loss in the caudate nucleus then putamen

187
Q

what is the main symptom of Huntington’s disease

A

choreiform (rapid, jerky movements, personality changes, and/or dementia)

188
Q

what is seen on a scan in a patient with Huntington’s diesease

A

enlargement of lateral ventricles

neurology (11 decks)

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