neuro patho Flashcards
1
Q
what are the time frames of fetal development
A
Pre-embryonic: fertilization to 2wks
Embryonic: 2-8wks
Fetal: >8wks
2
Q
what stage do the majority of organs develop
A
embryonic
3
Q
when is neuro development
A
2-20wks
4
Q
what are blastomeres
A
cells from first mitotic division
5
Q
what is a morula
A
The spherical embryonic mass of blastomeres formed before the blastula and resulting from cleavage of the fertilized ovum.
6
Q
what is a blastocyte
A
when a cavity forms in the morula
7
Q
which develops last (ectoderm, endoderm, mesoderm)
A
mesoderm
8
Q
where are the ectoderm, endoderm, mesoderm formed
A
Ectoderm(Upper lip)
Endoderm (Lower lip)
mesoderm froms between them
9
Q
what is the synchiotrophoblast
A
epithelial covering of the trophoblast that forms deep into the endometrial lining to establish nutrient circulation between the embryo and the mother
10
Q
what is the cytotropoblast
A
inner layer of the tropoblast. deep to the synchiotrophoblast
11
Q
what develops from the ectoderm
A
Sensory Organs
Epidermis
Nervous
System
12
Q
what develops from the mesoderm
A
Dermis Muscles Skeleton Urogenital Systems Circulatory System
13
Q
what develops from the endoderm
A
GI System
Liver
Pancreas
Respiratory System
14
Q
what is neurulation
A
process of neural tube(spinal cord) formation
15
Q
what is primary neurulation
A
infolding of neural plate
16
Q
what is secondary neurulation
A
sacral and cocyxgeal formation
17
Q
what portion of the neural plate is the last to close
A
inf region
18
Q
what should occur by the 3rd week
A
dorsal midline ectoderm thickens to form neural plate
19
Q
when should the ecoderm folds touch and close
A
touch at 21 days
close at 27 days
20
Q
what do neural crest cells form
A
PNS, Posterior root ganglia Sensory: cranial nerves Autonomic ganglia Adrenal medulla Melanocytes Pancreatic Islets
21
Q
what are radial glial cells
A
important for migrating neuroblasts and pivotal in CNS formation
22
Q
what do the bumps on the ectoderm represent
A
each bump is a somite and represent dermatomal development of the dermis
23
Q
what is colchicine and what is its SE
A
drug used for gout. cnat use in child bearing age women bc it blocks microtubules causing neurotube defects
24
Q
what is the notochord
A
defines the long axis
orients vertebrae
nucleus pulposus
cell adhesive molecules
25
what is the alar plate
sensory
26
what is the basal plate
motor
27
what is polyneuronal development
migration of cells in the fetal stage
>50% die in the process of migration
Usually completed by 25th week
28
when does myelination occure (specifically Corticospinal tracts and Cortical association fibers)
Begins 4th month of gestation and finished by 3 years of age.
Corticospinal tracts myelinated by 2 years
Cortical association fibers by 3 years of age
29
what are association fibers
allow one cortex to make connections for fine motor skills
30
what are the causes and defects associated with closure 1
Folic acid deficiency
Metabolic teratogens
causing Spinal Bifida
31
what are the causes and defects associated with closure 2
Maternal hyperthermia
Folic acid deficiency
Metabolic teratogens
causing Anencephaly
32
what are the causes and defects associated with closure 3
Usually resistant
| causing Mid-facial clefts
33
what are the causes and defects associated with closure 4
Maternal hyperthermia
| causing Cephalocele
34
what are the causes and defects associated with closure 5
Valproic acid exposure
| causing Sacral Meningocele
35
what is meningoencephalocele
meninges and brain tissue out of skull bc altered cranium closure
36
what is meningocele
meninges out of skull bc altered cranium closure
37
what is meningohydoencephalocele
meninges,ventricle, and brain tissue out of skull bc altered cranium closure
38
what are the characteristics of anencephaly
cerebral hemispheres replaced by vascular tissue making a frog like appearance
Protruding eyes:
Prominent nose
Long Arms
Most die in utero or within 1 week after birth
Rostral neuropore fails to close
Brainstem usually intact
39
what is spina bifida occulta
failure of dorsal vertebrae to close
10% of population(L5-S1)
usually asymtomatic
40
what is spina bifida-Meningocele
usually no deficits
41
what is spina bifida-meningomyelocele
part of cord gets outside
| always defects
42
what is myeloschisis
spina bifida with no overlying skin
| cord exposed on surface
43
what is arnold chiari
inf cerebellum and medulla protrude through foramen magnum
44
what are the manifestations of arnold chiari
```
asymptomatic
CN defect (usually IX-XII)
cerebellar defect
hydrocephalus
migraine
```
45
what is holoprosencephaly
Single large ventricle with fusion of midline structures, including thalami.
Affected fetuses and neonates typically have severe facial defects, such as cyclopia
46
what are possible causes of holoprosencephaly
Underlying chromosomal abnormalities, such as trisomy 13, or maternal diabetes mellitus are possible causes, but some cases are sporadic.
47
what are the somatic senses
Pain
Temperature
Crude touch/pressure
Discriminatory touch
48
what is stereognosis
the ability to perceive and recognize the form of an object
49
what is graphesthesia
ability to recognize writing on the skin purely by the sensation of touch
50
nociception
Recognition and signaling of a deleterious stimuli
51
pain
Conscious awareness of the nociceptive event
52
suffering
Emotional and behavioral sequelae
53
deafferentiation pain
pain due to loss of sensation of an afferent fiber
54
hyperalgesia
increased sensitivity to stimulation
55
what causes pain afferent nerve endings
"naked nerve endings" activated by thermal, mechanical, or chemicals increasing Na permeability= inc APs
56
what chemicals can activate afferent pain nerves
H+, bradykinin, histamine, prostaglandin, hypoxia
57
what are A-delta fibers (location, stimuli, type of pain, size, myelination, speed)
```
afferent pain neuron
Location: body surface/skin
Stimuli: mechanical, thermal, chemical
Type of pain: sharp, prickly
Large diameter
Myelinated
5-30 m/sec
```
58
what are C-fibers (location, stimuli, type of pain, size, myelination, speed)
```
Location: deep skin/ tissue
Stimuli: thermal, mechanical, chemical
Type of pain: aching, burning
Large diameter
Unmyelinated
.5-2 m/sec
```
59
what is Lissauers tract
Afferent pain fibers go a few segments up or below before crossing over
60
where would pain and temp loss in reguards to a spinal cord lesion
typically 2 segments down from lesion not at the lesion
61
where do I, II, and IV lamina send signals to
I and II- to brain
| IV- reflex(not to brain)
62
why does chronic pain cause insomnia
the C-fibers signal the RAS on the way to the thalamus.
63
what is the pathway of the neospinothalmic tract
RAS
Thalamus(VPL)
Somatosensory cortex
Pain localization and intensity
64
what is the pathway of the paleospinothalmic tract
```
RAS (more than neospinothalmic)
Thalamus(VPL
Limbic (emotion, inc aggression with chron pain)
Somatosensory Cortex
Emotional response to pain
```
65
what is the Periaqueductal gray
in the midbrain
activated by Mu-R
release Enkephalin and neurotension at the Raphe Nucleus in the medulla
66
what does the raphe nucleus do
activated from periaqueductal gray
| releases 5-HT and Enkephalin at terminal afferent neuron to block release of substance P and block pain
67
what does 5-HT do
causes more enkephalin release
68
what does enkephalin do
endogenous opiod that blocks substance P release to block pain
69
what does Fentinil do
used in epidurals to bind opiod Mu-R and prevent substance P release= block pain
70
why do they give tricyclic antidepressents for chr pain
block seratonin, dopamine, NE reuptake to alleviate pain
| Keeps seratonin around so Enkephalin can block substance P
71
what is the danger of epidurals and intrathecal(sub arachnoid) opiod administration
can diffuse upward and stop breathing
72
how do local anesthetic agents work
block Na channels
73
what is lidocaines and Marcaines(bupivicaine) MSD
Lido=5-7mg/Kg
Marcaine= 2-3 mg/kg
(can use the higher doses if epi is used bc keeps it local)
74
what is the toxicity from Lidocaine
CNS before cardiac
CNS: twitch, tinnitus, Sz
Cardiac:heart block
75
what is the toxicity from Marcaine
Cardiac before CNS (need to be on cardiac monitor. watch for vfib)
76
what is 1% lido
1g/100ml or 10mg/mL
77
how do NSAIDs dec pain
block prosteglandin production
78
how does a cordotomy help pain
lateral spinothalmic tractotomy= loss of pain on one contralateral side one to 2 segments down
Temporary relief
79
What is a Rhizotomy
cut dorsal root to prevent pain but also blocks other sensory
80
what does a lesion of intralaminar nuclei do
decreases suffering type of pain and leaves the acute pain
81
what does a VPL lesion cause
Lesion is in thalamus causing contralateral loss of all sensory
82
what does a VPM lesion cause
lesion is in the thalamus causing contralateral loss of facial sensory
83
what is radicular pain vs local pain
radicular pain is along a dermatome
84
what is thalamic syndrome
Posteriolateral branch of posterior cerebral artery (anterior thalamus OK)
Loss of sensation opposite side of body bc VPL and VPM blocked
Ataxia
Usually damage to internal capsule
After insult there is hemianesthesia followed by burning pain after several weeks
85
how does the cerebellum and thalamus maintain balance
cerebellum compares intended action to actual act and makes adjustments. Adjustments are sent through thalamus to upper motor cortex.
86
what is the pain component of complex regional pain syndrome(reflex sympathetic dystrophy)
Out of proportion to injury
Burning, numbness, tingling, itching
May be confined to dermatomal or diffuse (less diffuse and of a vascular distribution)
Usually distal
Superficial nonnoxious stimuli: ie air accentuates pain
Behavioral changes: seclusion/withdrawn
87
what is the circuit of continuing pain in complex regional pain syndrome
Pain= inc SNS= dec circulation=hypoxia/inc H+=inc Pain
88
what is CRPS I
triggerd by tissue inj with no identified nerve inj
| AKA reflex sympathetic dystrophy(RSD)
89
what is CRPS II
Associated with nerve inj
| AKA causalgia
90
what is the 2nd component of complex regional pain syndrome
```
unspecified abnormalities of sensation, motor function and blood flow
Soft puffy edema
Skin color changes
Cold or warm
Joint limitations
```
91
what is the 3rd component of complex regional pain syndrome
```
Sweating and trophic changes in the skin and soft tissue
Excessive moisture or dryness
Increased hair or nail growth
Osteoporosis(dec circulation)
Muscle atrophy(dec circulation)
```
92
what are the three types of pain from complex regional pain syndrome
1Algodystrophy: pain and all features of dystrophy
2Dystrophy without pain
3Sympathetically maintained pain, not exhibiting dystrophic changes
93
what is the 1st stage of complex regional pain syndrome
pain is in the limb.
distribution is not compatible with single nerver, trunk, or root lesion
vasomotor disturbance
radiology normal
94
what is the 2nd stage of complex regional pain syndrome
progressive soft tissue edema, thickening of skin, mm wasting
95
is the 3rd stage of complex regional pain syndrome
limitation of movement, contractures, bone demineralization
96
what is the Tx of complex regional pain syndrome
```
Medications
-Phenoxybenzamine hydrochloride (alpha blocker)
-Clonidine (alpha 2 agonist)
-GABA analogs
Nerve blocks
-Inject into dorsal root ganglion
```
