Block 2 Flashcards
1
Q
at what day does gastrulation occur
A
12
2
Q
at what day does neurulation occur, what signifies the start
A
16
neuroectoderm
3
Q
at what day does the neural tube close
A
21-28
day 21= anterior pore
day 28= posterior pore
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
5
Q
what are the divisions at the 3 vesicle stage
A
rhombencephalon (hindbrain)
mesencephalon (midbrain)
prosencephalon (forebrain)
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
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)
8
Q
SHH is involved in what function
A
motor
9
Q
what forms from the telencephalon
A
cerebral hemispheres
basal ganglia
10
Q
what forms from the diencephalon
A
thalamus
pineal gland
hypothalamus
neurohypophysis
retina
11
Q
what forms from the mesencephalon
A
midbrain
12
Q
what forms from the metencephalon
A
pons
cerebellum
13
Q
what forms from the myelencephalon
A
medulla
14
Q
what are 2 aspects of the developing neural tube
A
alar plate
basal plate
15
Q
is the alar or basal plate the dorsal vs ventral aspect of the neural tube
A
alar plate= dorsal
basal plate= ventral
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)
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)
18
Q
what divides the alar and basal plates
A
sulcus limitans
19
Q
what does the cerebellum develop from
A
rhombic limb
20
Q
at what time does the cerebellum develop
A
week 5-6
21
Q
the central part of the rhombic limb becomes the __
the lateral parts are the __
A
central- vermis
lateral- cerebellar hemispheres
22
Q
when does growth from the telencephalon occur
A
week 5
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
24
Q
what are the 3 major components of the basal ganglia in the telencephalon
A
caudate nucleus
putamen
globus palidus
25
what are the 2 components of the basal ganglia which are found in the diencephalon or midbrain
substantia nigra
subthalamus
26
the limbic system functions for __ and __
emotion and memory
27
most of the components of the limbic system come from what
telencephalic vesicle neurons
28
the lateral ventricles come from what embryonic structure
telencephalic hemisphere
29
the third ventricle comes from what embryonic structure
diencephalon
30
the fourth ventricle comes from what embryonic structure
rhombencephalon
31
when does myelination of the spinal cord begin
4th month (week 16)
32
when does myelination of the brain begin
6th month
33
when does myelination of the corticospinal tract begin
6th months post-natal
34
when is myelination of the spinal cord complete
it continues until at least 2.5-3 years
35
when does myelination of the brian complete
it may continue up to age 20-25 in the frontal lobes
36
what is the cause of a Babinski reflex present in those under age 2.5
incomplete myelination of corticospinal tracts
37
what is the mechanism of anencephaly
failure of anterior neuropore closure between day 25-28
38
what causes anencephaly
folic acid deficiency
39
what is the mechanism of spina bifida
failure of posterior neuropore closure
40
what is the characteristic of spina bifida occulta
benign
41
what is the characteristic of spina bifida cystica meningocele
protrusion of meninges
42
what is the characteristic of spina bifida meningomyelocele
protrusion of meninges and nerves
43
what is the characteristic of spina bifida myelocele
protrusion of nerves
*this is the worst type of spina bifida
44
what is the mechanism of encephalocele
failure in processes associated with closure of anterior neuropore
45
what are the 2 main causes of encephlocele
folic acid deficiency
teratogens
46
what is a main concern of hemorrhage of the placenta during the second trimester
underdevelopment of part of the cerebral cortex
(germinal matrix hemorrhage)
47
what causes gray matter heterotopia
failure of cortical cells to migrate to their final position of the cortex
48
what causes gray matter heterotopia
interruption in germinal matrix, especially during 2nd trimester
49
what causes lissencephaly
failure of cortical cells to migrate to their final position in the germinal matrix
50
what is a common characteristic of lissencephaly
smooth brain lacking gyri
51
Arnold Chiari malformation is characterized by herniation of __ in type
I= __
2=__
3/4=__
1= cerebellar tonsil
2= cerebellum
3= lower brain stem through foramen magnum
52
Dandy Walker syndrome is visible by what
complete or partial cerebellar agenesis, often the vermis
53
what are the symptoms of Dandy Walker syndrome
dilated 4th ventricle
hydrocephalus
small vermis (absent or small)
54
syringomyelia is characterized by what
abnormal enlargement of the central canal of the spinal cord, often damaging fibers of the spinothalamic tract
55
what are the 3 broad categories of cerebral palsy
spastic
ataxic
athetoid/dyskinetic
56
what is the most common type of cerebral palsy
spastic
57
what type of damage is common in those with spastic cerebral palsy
upper motor neuron lesions and GABAnergic receptor dysfunction in the spine
58
what type of damage is common in those with ataxic (intension/action tremors) cerebral palsy
cerebellar
59
what type of damage is common in those with athetoid (dyskinetic) cerebral palsy
damage to basal ganglia or just the substantia nigra
60
what are the 2 classes of athetoid (dyskinetic) cerebral palsy
choreoathetoid
dystonic
61
how do choreoathetoid and dystonic cerebral palsy differ
choreoathetoid- involuntary movements in the face and extremities
dystonic- strong, slow contractions, whole body or local
62
how does ATP act as an inflammatory chemical
ATP activates peripheral nociceptors, signaling the presence of inflamed tissue, producing pain
63
how do neutrophils act as an inflammatory chemical
they synthesize COX-2 which metabolizes arachidonic acid into prostaglandins and cytokines
64
how does prostaglandin PgE2 act as an inflammatory chemical
it blocks K+ efflux from nociceptors causing additional depolarization and altering pain sensitivity by increasing the responsiveness of peripheral nociceptors
65
how do nerve growth receptors act as inflammatory chemicals
they promote structural reorganization and alteration in the patterns of nerve connections
66
the neospinothalamic tract is involved in what aspect of pain
direct consciousness
67
the neospinothalamic tract directs to the __
VPL
68
the paleospinothalamic tract is involved in what aspect of pain
indirect arousal/emotional impact of pain
69
there are 3 pathways of the paleothalamic tract. these include...
1. general paleothalamic to cingulate gyrus
2. spinoreticular to cerebral cortex
3. spinotectal/spinomesencephalic
70
what is analgesia
insensibility to pain without loss of consciousness
71
what is anesthesia
insensitivity to pain with induced loss of consciousness
72
what is paresthesia
numbness (pins and needles)
73
what is hyperalgesia/hyperesthesia
enhanced sensation to pain due to exposure of inflammatory factors
*prostaglandin E2 can cause hyperalgesia
74
what is allodynia
feeling of pain sensation following a non-painful stimulus
75
what is neuralgia
neuropathic pain not related to activation of pain receptors
76
what is phantom pain
pain sensation felt in an amputated body area due to over activity of a second order pain mediating neuron
77
what is thalamic pain syndrome (Dejerine-Rousy)
pain caused by vascular lesion to VPL of the thalamus
78
what is trigeminal neuralgia (Tic douloureux)
neuralgia of the areas innervated by CNV (trigeminal)
79
trigeminal neuralgia is associated with compression of the trigeminal nerve root by what artery
superior cerebellar artery
80
what are 2 main treatments for trigeminal neuralgia
carbamazepine (stabilizes closed Na+)
phenytoin (blocks Na+)
81
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
only at site of lesion
82
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
at site of lesion and below
83
what is contained in the lateral horn
preganglionic sympathetic autonomics
84
in what vertebrae segments are preganglionic sympathetic autonomics located
T1-L2
85
alpha motor neurons supply __
gamma motor neurons supply __
alpha= skeletal muscle
gamma= muscle spindles
86
what are the 2 branches of the motor division of the PNS
autonomic
somatic
87
what are the 2 classes of receptors of the autonomic nervous system
cholinergic
adrenergic
88
cholinergic receptors of the autonomic nervous system can be classified as __ or __
nicotinic
muscarinic
89
nicotinic cholinergic receptors use __
muscarinic cholinergic receptors use __
(GPCR vs ligand gated)
nicotinic= ligand gated ion channel
muscarinic= GPCR
90
nicotinic ACh receptors are found where
neuromuscular junction
preganglionic synapses
adrenal medulla
throughout CNS
91
what are the 2 classes of nicotinic receptors
N1/Nm at neuromuscular junction
N2/Nn at autonomic ganglia, CNS, and adrenal medulla
92
does epinephrine bind to alpha or beta adrenergic receptors with higher affinity
beta
93
does norepinephrine bind to alpha or beta adrenergic receptors with higher affinity
alpha1>alpha2>beta1
94
does epinephrine or norepinephrine cause a greater response at beta 2 nicotinic receptors
epinephrine
95
which adrenergic receptor type acts as an autoreceptor (negative feedback system)
alpha2
96
what are beta 1 adrenergic receptors responsible for
increased heart contractility/CO/HR
increased renin release through juxtaglomerular cells
97
alpha 1 and beta 1 adrenergic receptors are mainly __ responses
alpha 2 and beta 2 adrenergic receptors are mainly __ responses
1= excitatory
2= inhibitory
98
does the adrenal medulla release more epinephrine or norepinephrine
80% epinephrine
20% norepinephrine
99
activity of what hormones contributes to sympathetic tone during waking hours
adrenal medullary (high cortisol at night, high adrenaline during the day)
100
preganglionic neurons of the parasympathetic nervous system comprise cell bodies of cranial nerves __ which are all located in the brain stem
3, 7, 9, 10
101
parotid gland surgery can result in damage to what nerve
facial (CN 7)
102
what are the 2 parasympathetic preganglionic neurons of cranial nerve X
dorsal motor nucleus (viscera of lungs and abdomen)
nucleus ambiguus (muscles of pharynx, larynx, heart)
103
are pelvic splanchnic nerves sympathetic or parasympathetic
parasympathetic
104
what is the sympathetic receptor found in the eyes, what is the response
alpha1
pupil dilation (mydriasis
105
what is the sympathetic receptor found in the vascular smooth muscle
what is the response
alpha1 with vasoconstriction>beta1 with vasodilation
106
what is the sympathetic receptor found on the sweat glands
what is the response
acetylcholine onto M3
107
what is the sympathetic receptor found on myocardiocytes
what is the response
beta1
increase contractility, increase HR
108
what is the sympathetic receptor found on the lungs what is the response
beta2
increase bronchodilation, decrease secretions
109
what is the sympathetic receptor found in the digestive tract
what is the response
alpha2
decrease peristalsis and secretions
110
what is the sympathetic receptor found on the rectum/anal sphincter
what is the response
alpha1
contracts internal anal sphincter
111
what is the sympathetic receptor found on the liver
what is the response
beta2
increase glycogenolysis
112
what is the sympathetic receptor found on juxtaglomerular cells
what is the response
beta1
increase renin release
113
what is the sympathetic receptor found on the detrusor muscle
what is the response
beta3>beta2
relaxation, urine storage
114
what is the sympathetic receptor found bladder internal sphincter
what is the response
alpha1 contraction
urine storage
115
what is the sympathetic receptor found on the renal medulla
what is the response
Ach onto Nn (nicotinic AChR)
116
what is the parasympathetic receptor found on the eyes
what is the response
M3
pupil constriction (myosis)
117
what is the parasympathetic receptor found on the vascular endothelium
what is the response
M3
vasodilation through production of Nitric Oxiide (NO)
118
what is the parasympathetic receptor found on the myocardiocytes
what is the response
M2 (atrium>ventricles)
↓contractility >↓ heart rate
119
what is the parasympathetic receptor found on the lungs
what is the response
M3
↓bronchodilation , ↑secretions
120
what is the parasympathetic receptor found on the digestive tract
what is the response
M2>>>M3
↑peristalsis and secretions
121
what is the parasympathetic receptor found on the detrusor muscle
what is the response
M3
contraction, urine voiding
122
what is the parasympathetic receptor found on the bladder internal sphincter
what is the response
M3 and M2
relaxation through unknown mechanism
123
what is the sensory presentation of acute ulnar nerve neuropathy
numbness/tingling
124
what is the sensory presentation of chronic ulnar nerve neuropathy
loss of sensation over the medial 1.5 fingers and palm
125
what is the motor presentation of ulnar nerve neuropathy
wasting of interosseous muscles
reduction/loss of abduction and adduction of fingers
126
what are the 2 sites that cubital tunnel syndrome can affect
ulnar groove (elbow)
cubital tunnel (forearm)
127
what are the 5 causes of cubital tunnel syndrome
trauma
compression/entrapment
diabetes
rheumatoid arthritis
overactivity
128
what are the 5 causes of Guyon's canal syndrome
trauma
compression/entrapment
diabetes
rheumatoid arthritis
overactivity
129
what is the site of Guyon's canal syndrome
Guyon's canal which is in the wrist
130
if there is severe motor involvement with ulnar nerve neuropathy, what is the management
surgery
131
carpal tunnel syndrome is the result of entrapment of what nerve
median
132
where is the site of carpal tunnel syndrome
wrist at flexor retinaculum
133
what is the sensory presentation of carpal tunnel syndrome
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
what is the motor presentation of carpal tunnel syndrome
weakness/wasting of thenar muscles (abductor pollicis brevis)
135
what is the non-surgical management of carpal tunnel syndrome
oral or injection glucocorticoid for short term relief
136
what is involved in surgery for carpal tunnel syndrome
open carpal tunnel or endoscopic carpal tunnel release
137
what is the sensory presentation of herpes zoster
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
what is the treatment for herpes zoster
oral or topical acyclovir
139
what is the cause of herpes zoster (shingles)
varicella zoster virus
140
what is a nerve conduction study
a test used to evaluate the function, especially the ability of electrical conduction, of motor and sensory nerves of the body
141
in a nerve conduction study, amplitude decrease is more indicative of __, while velocity decrease is more indicative of __
amplitude- nerve damage
velocity- demyelination
142
how does referred pain arise
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
what causes CIPA (congenital insensitivity to pain with anhidrosis)
absence/mutation in neurotropic tyrosine kinase receptor 1 which usually binds nerve growth factor to help axons reach their targets
(C-fibers)
144
what nerve fiber type is affected by CIPA (congenital insensitivity to pain with anhidrosis)
C-fibers
145
how does water soluble olfactory transduction differ from water insoluble
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
how many receptor types are expressed by each olfactory neuron which get clustered in a single ganglion
1
147
what are the primary olfactory sensory neurons
bipolar ciliated olfactory cells
148
do olfactory primary neurons regenerate
yes
149
what are the main output cells (second order neurons) that become the olfactory tract
mitral and tufted cells
150
what is an olfactory transport disorder of olfaction
rhinitis
151
what are 3 olfactory sensory disorders of olfaction
viral infection
cigarette smoking
fracture of cribriform plate of ethmoid
152
what is a neural disorder of olfaction
psychotic disorders
153
the afferent nerves of cranial nerves ___ make up the cell bodies of 1st order neurons of taste
CN 7, 9, 10
facial, glossopharyngeal, vagus
154
what taste papillae make up the anterior 2/3 of the tongue
filiform
fungiform
155
what taste papillae makes up the posterior 1/3 of the tongue
foliate
156
what type of channels do each of the 5 basic tastes use
salty and sour use ion channels
sweet, bitter, and umani use G protein
157
what is ageusia
loss of taste
158
what is dysgeusia
distorted perception of taste
159
what is phantogeusia
perception of taste where there is none
160
what are 2 transport disorders of taste
Sjogren syndrome (autoimmunity against salivary and lacrimal glands)
xerostomia (dry mouth)
161
what are 2 sensory disorders of taste
antibiotics/insecticides
candida
162
what are 3 neural disorders of taste
cigarette smoking
Bell's palsy (CN VII)
stroke
163
what is the most common cause of taste dysfunction
medication
164
what is the sequence of initiation of voluntary muscle movement between upper and lower motor neuron and the muscle
upper motor neuron innervates a lower motor neuron which innervates the muscle
165
where is the location of upper motor neurons compared to lower motor neurons
upper- motor cortex
lower- motor nuclei of cranial nerve and ventral horn of spinal cord
166
alpha motor neurons innervate __
gamma motor neurons innervate __
alpha- extrafusal fibers (skeletal muscle)
gamma- intrafusal (muscle spindles) to maintain spindle stretch
167
what 4 symptoms of a lower motor neuron injury
muscle fasciculation (twitching)
flaccid paralysis
areflexia
muscle atrophy
168
what is the function of muscle spindles
provide sensory afferents about muscle length and stretch
169
what part of the muscle spindle contains contractile muscle fibers and receives input from gamma lower motor neuron efferents
ends of the fiber
170
what maintains muscle spindle sensitivity over a muscle length/stretch
gamma lower motor neurons
171
what is the function of spinal interneurons
integrate cutaneous, proprioceptive, and supraspinal influences in the control of movements, muscle tone, and power through modulating activity of lower motor neurons
172
what are Renshaw cells
inhibitory glycinergic neurons in the ventral horn of the spinal cord which mediate reciprocal inhibition of Ia afferent excitation of lower motor neurons
173
what is the cellular activity that causes tetanus
inhibition of cells by tetanospasmin
174
what is the autoregulatory method that axons of the lower motor neurons use
axons of lower motor neurons have recurrent branches that synapse onto Renshaw cells which then inhibit the same lower motor neurons
175
what is the cellular activity of tetanus
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
the lateral corticospinal tract is most responsible for control of __ musculature
the anterior corticospinal tract is most responsible for control of __ musculature
lateral= appendicular/distal
anterior= axial/proximal
177
what prevents the spread of the toes with the Babinski reflex after around age 2
myelination of corticospinal tract
178
what type of neurons make up the caudate and putamen (dorsal striatum)
medium spiny neurons
179
what type of neurons make up the globus pallidus (dorsal pallidum)
medium aspiny neurons
180
what is the function of the caudate and putamen (dorsal striatum)
process converging motor and sensory input
181
what is the function of the globus pallidus (dorsal pallidum)
disseminate processed information to the thalamocortical feedback loop
182
pars compacta of the substantia nigra contains what class of neurons
dopaminergic
183
pars reticulata contains what class of neurons
GABAnergic
184
what is the major neurotransmitter produced by the substantia nigra
dopmaine
185
what is the cause of Huntington's disease
increase in CAG repeats in the HTT gene
186
what is the neurological presentation of Huntington's disease
neuronal loss in the caudate nucleus then putamen
187
what is the main symptom of Huntington's disease
choreiform (rapid, jerky movements, personality changes, and/or dementia)
188
what is seen on a scan in a patient with Huntington's diesease
enlargement of lateral ventricles
