anatomy and phyisology part 2 Flashcards
(148 cards)
1
Q
watershed areas of the brain
A
ACA and MCA - upper leg and upper arm weakness
PCA/MCA - higher order visual processing
2
Q
ACA supplies
A
along olfactory bulbs on inferior surface of brain and medial parietsla dn fromtal lobes and then just arms on the medial surface
3
Q
MCA supplies
A
inferior frontal poles and then superior temporal on the medial side and medial surface fo frontal and parietal lobes
4
Q
PCA supplies
A
infetiot temporal and occipital and then interior temporal on medial border
5
Q
what is most common site of aneurysm in the circle of willic
A
anterior communicationt
6
Q
occlusion to the anterior cerebra; =
A
lower limb affected
7
Q
occlusion of the middle cerebral
A
upper limb and face weakness and werknickes (fluent, impaired comphrehension and cannto repeat)
8
Q
sxs of aneurysm in the posterior communicating
A
can affect CN III - down and out, ptosis, pupillary light reflex and vasodilation
9
Q
occlusion of the posterior cerebral
A
hemanopia with macular sparing
10
Q
two vessels that sandwich cranial nerve III
A
posterior cerebral and superior cerebellar
** also near CN VI
11
Q
branches of the internal carotid please
A
middle cerebral – ophthalmic and the lenticulstriacte
12
Q
what events can occur in the middle cerebral
A
thrombotic iscahemic strokes
13
Q
what events typicaly occur at the lenticulostriate vesesl
A
hypertension
hemorrhagic stroke
14
Q
symptoms of issues with lenticulostriate blood supply loss
A
hemiparesis
hemiplegia
(striatum and internal capsule)
15
Q
anterior inferior cerebellar acrtery occlusion
A
lateral pontine CNVII
16
Q
posterior inferior cerebellar artery occlusion
A
lateral medullary CNX
WALLENBERG SYNDROME
17
Q
what is wallenbuerg syndrome
A
lateral medullary with CN X
PICA occlusion
18
Q
anterior spinal artery occlusion
A
medial medullary syndrome
at spc - all but the dorsla colomns
CN XII
19
Q
what is the homunculus
A
topgraphic representation of motor and sensory areas in the cerebral cortex. distorted appearance bc certain body regions are more richly innervated and thus have increased cortical represertnation.
20
Q
describe the layout of the homunculus
A
feet dangle over the medial border with the kneea t the top. then roso and shoulders and elbow and arms. hands are at about 1-2 oclock and eyes thake over till reach chin at about 3 oclock then have toge at foru oclock lateral side
21
Q
how is cerebral perfusion regulation
A
on tight autoregulation between 60- 150 mmHg
primarily driven by PCO2 with influence of PO2 in severe hypoxemia (less than PO2=50)
22
Q
describe PO2 effect on cerebral blood flow
A
when PO2 reaches levels below 50 mmHg, will cause vasodilation to increased blood flow
above PO2 fo 50 mmHg, see no effect on cerebral blood flow
23
Q
describe PCO2 effects on cerebral blood flow
A
at PCO2 of 0 to PCO2 of 90 see an increased in cerebral perfusion - then levels off
PCO2 causes vasodilation at increasing levls
24
Q
how can you use the autoregulation of cerebral blood flow therapeutically
A
if person has increased ICP - hyperventilate to decrease bc lower levels of PCO2 cause vasoconstriction
ie in cases of cerebral oedema - want to hyperventilate to decrease PCO2 and have less blod flow
25
pathophys of fainting in a panic attack please
hyperventilation in panic attack leads to dereased PCO - less vasodlation - less cerebral blood flow - fainting.
26
what does cerebral perfusion depend on
a gradient between system blood flow and icp
| CPP = MAP-ICP
27
what is the influence of MAP and ICP on CPP?
MAP decreases = decreased CPP
ICP increases = decreased CPP
CPP = MAP - ICP
28
what happens if CPP is zero
no cerebral perfusion - brain death
29
what is an aneurysm
an abnormal dilation of artery due to weakening of the vessel wall
30
what is a saccular/berry anuerysm
occurs at the birucrations in the circle of willis
31
most common site of berry anuerysm
anterior communicating and anterior cerebral artery junction
32
what is the most common compliation of berry aneurysms and the consequences
most common complication of berry aneurysm is RUPTURE -- subarachnoid hemorrhage ''worst headache of my life'' or hemorrhagic stroke
33
if presents wit bitemporal heminanopia look for
prolactinoma/craniopharyngioma/aneurysm in AComm/ACA
34
what are risk factors for berry aneurysms
```
Ehlers Danlos
ADPKD
advanced age
hypertension
smoking
increased incidence in blacks
```
35
what is a charcto-bouchard microaneurysm
affects small vessels ie lenticulostriates
associated with chronic hypertension
basal ganglia and thalamus (internal capsule)
36
describe central post stroke pain syndrome
neuropathic pain due to thalamic lesions
intintall:paresthesias --> week to month slater allogynia (ordinary non painful stimuli cause severe pain) and dysestheisa (imparment of sensation sp touch)
10% of stroke pateitns
37
pt presentation: paresthesias then weeks/months later have allodynia and dyesthesias
thalamic lesions
central post stroke pain syndrome
**think of like UMN and LMN lesions in spinal cord injury)
38
epidural hematoma pathogenesis
rupture of middle meningeal artery (maxillary artery branch - Dr Curry KBT) - secondary to temporal bone
39
epideurla hemoatome presetnation
lucid invtercail
rapid expansion - systemic arterial pressure
biconvex/lentiform with hyperdense blood collection
40
epidural hematoma local
no cross suture lines
| yes croos falx and tentorium
41
pathogenesis of subdural hematoma
rupture of bridging veins
42
presentation of subdural hematoma
@ risk groups: elderly, OHics, infants, blunt trauma ie brain atrophy, shaking, whiplash
43
clinical findings in subdural hematoma
crescent shaped hemorrhaces
crosses suture lines
cannot corss falx or tentorium
can present with acute ( lighter on imaging) and chronic (darker on imaging)
44
pathogenesis of subarachnoid hemorrhage
rupture of an aneurysm (berr in ED or ADPKD) or arteriovenous malformation
45
presentation of subarachnoid hemorrhage
rapid time course
worst headache of my life
blood or xanthochromic/yellow spinal tap
2-3 days later have risk of vasospasm due to blood break down and rebleed
46
how to treat vasospasm post subarachnoid hemorrhage
NIMODIPINE CCB
47
nimodipine
CCB used to treat vasospasm post subarachnoid hemorrahace
48
what is an intraparenchymal hemorrhage
most commonly cause by systemic hypertension
| also see with amyloid angiopathy, vasculitis, neoplasm
49
where do intraparenchymal hemorrhages typical occur
int he basal cganglia and internal capsule - charcot bouchard aneurysms of lenticulostriate cessels
can be lobar
50
who is at risk of itnraparenchymal hemorrages
pts with hypertension
amyloid angiopathy in elderly
vasculitis
neoplams
51
what is recurrent lobar hemorrhagic stroke
in elder with amyloid angiopathy
| a intraparenchymal hemorrhage
52
compare how subarachoid vrs intraparenchymal strokes show up on imaging
subarachoind - along folds of brain surface
| intraparenchymal - blob
53
how long does it take to get irrevesribel damage in ischaemic brain disease
within 5 minutes
54
which areas of the brain are most vulnerable to ischemic brain disease
hippocampus
neocortex
cerebellum
watershed
55
what do hippocampus, neocortex, cerebellum and watershed areas have in common
most vulnerable to iscahemic brain trauma
56
what must do before can give tPa for strokes
noncontrast CT to exclude hemorrhage
57
when will CT detect ischemic changes
6-24 hours after event
58
when will diffusion weighter MRI detect iscahemic changes
3-30 mins post event
59
histologic feature of icahemic damage and time course pelase
```
12-48 hours - red neurons
24-72 hours - necrosis and PMN
3-5 days - macrophages/microglia
1-2 weeks - reactive gliosis and vascular proligeration
>2 weeks - glial scar
```
60
histo feature of ischaemic changes @ 12-48 hours
red neurons
61
histo feature of ischaemic changes @ 24-72 hours
PMN and necrosis
62
histo feature of ischaemic changes @ 3-5 days
microglia/macrophages
63
histo feature of ischaemic changes @ 1-2 weeks
reactive gliosis and vascular proliferation
64
histo feature of ischaemic changes @ > 2 weeks
glial scar
65
when do you see red neurmos
post iscahemic trauma 12-48 hours
66
when do you see necrosis and PMNs
24-72 hours post iscahemic trauma
67
when do you see microglia
3-5 days post iscahemic trauma
68
when do you see reactive gliosis and vascular proliferation
1-2 weeks post ischaemic trauma
69
when do you see glial scar
> 2 weeks post iscahemic trauma
70
what is a hemorrhagic stroke
intracerebral bleeding
71
what causes hemorrhagic stroke
hypertension
anticoagulation
cancer - abnormal cessels
secondary to ischemic stroke followed by reperfusion - increased vessel fragility
72
where is the most common site for intracerebral hemorrhage
the basal ganglia (hypertension, anticoagulation, caner)
73
what is an iscahemic stroke
acute blockage of vessels - disruption of blood flow and subsequent ischemia = LIQUEFACTIVE NECROSIS
74
what are the three types of iscahemic stroke
thrombotic
embolic
hypoxic
75
describe a thrombotic iscahemic stroke
due to clot forming directly at side of infarction usually over an atherosclerotic plaque
76
where is most common site of thrombotic iscahemic stroke
MCA
77
describe an embolic iscahemic stroke
embolus from another part of the body obstructs vessels. can affect MULTIPLE VASCULAR territories
78
what are risk factors for embolic ischaemic strokes
atrial fibrillation
| DVT with patent foreamen ovale (paradoxical)
79
describe hypoxic iscahemic stroke please
due to hypoperfusion or hypoxemia
| common during cardiovascular surgeries @ water shed areas
80
where do hypoxic ischameic strokes tend to occur
during cardiovascular surgeries @ water shed areas
81
how to treat ischaemic strokes
with tPA if within 3-4.5 hours of onste and no righ of hemorrahge
82
how do you reduce risk of stroke
medical therapy - aspirin and clopidogrel
contrl bp, sugars, lipids
treat conditions with increase risk ie atrial fibrillation
83
what is a transient iscahemic attack
brief, reversible episode of focal neurologic dysfunction without acute infarction - show on MRI (3-30 mins; diffusion weighted)
majority resolve in 15 mins
deficits - due to focal iscahemia
84
what are dural venous sinuses
large cenous channels that run through the dura. drain blood from cerebral veisn and received CSF from arachnoid granulations -- empty into internal ugular vein
85
pathway from superior sagittal to internal jugular vein pelase
superior sagittal - confluence of sinuses (meets up with straight sinus collecting from intferior sagittal sinus and the gret cerebral vein of galen AND the occipital sinus) - transveres - sigmoid - intrenal jugular
86
what two veins drain into the cavernous sinus
superior opthlamic vein
sphenoparietal sinus
TRIANGLE OF DOOM or something like that on face
87
describe the pathway of CSF drainage through the ventricular system
arachnoid villi -- lateral ventricles -- foramen of monro -- third ventricles -- cerebral aqueduct of slyvius - foruth ventricle - subarachonoid space via foramina of luschka and framen of magendie
88
describe pseudotumor cerebri
idiopathic intracranial hypertension - increased ICP with no apparent cause on imaging (ie no hypdrocephalus or obstruction fot CSF flow)
89
headache
diplopia
no metnal stauts alteration
papillemdema
psuedotumor cerebri/idiopathic intracranial hypertension
90
what are risk factors for pseudotumor cerebri
women of childbearing age
vitamin A excess
danazol
91
how to treat psuedotumor cerebri
LPs will have high opening pressure and procide headache relief
weight loss and acetazolamide, and topiramtae,
92
what if initital treatment for pseudotumor cerebri don't work
invasive for refractory cases - repeated LPs, CSF shunt placemnt, optic nerve fenestration surger
93
what Cn usually causes diplopia in pseudotumor cerebri
CNVI palsy
94
what is communicating hydrocephalus
decreased CSF absorption by arachnoid granulations - increased ICP, papilloedema, hernation
95
what causes communicating hydrocephalu
arachnoid scarring post meningitis
96
what is normal pressure hydrocephalus
often in elderly, idiopathyic
CSP pressure elecated ony episodically
no increase in subarachoind spave colume
97
describe symptoms of normal pressure hydrocephalus
ventricles expand and distort the fibres of the corona radiate -- wobbly wet and wacky/weird.
urinary incontinence
ataxia
congintive dysfunction
98
what is non communicating hydrocephalus
structural blockage of CSF circulation in the ventricular system
ie stenosis of aqueduct of sylvious, colloid cyst blocking foramen of monro
99
what is e vacuo ventriculomegaly
appearance of icnreaesd CSF of imagine but is actually due to derease brain tissue ie neural atrophy
ICP is normal
no triad
100
patients to suspect ex vacuo ventriculomegaly
hydrocephalus mimicry
| @ neuronal atrophy in Alzheimer disease, advanced HIV, and Pick disease
101
how many spinal nerve pairs are there
31 - 8 c, 12 t, 5 l, 5 s and 1 coccygeal
102
describe a vertebral disc herniation
nucleus pulposus the soft cenral disc remnant of the notochord - herniates through the annulus fiboruss
usually postero laterally at L4/5 ro L5/S1
103
where does the spinal cord ened in adults
L1/2`
104
where does the subarachnoid space extend to in adults
s2
105
where should you poke for the LP
L3-5 at the level of the cauda equina
106
to keep the cord alive keep the spinal needle between L 3 and L5
thanks fa
107
whats in the fasciculus gracilis?
lower bod and legs pvtp
108
whats in the fasciculus cuneatus
upper body and arm pvtp
109
whats in the anterior corticospinal tract
voluntary motor
110
describe where the cervical region is represented for each tract in the spc
cervical for lateral corticospinal tract @ closest to gray matter/medial
cervical for dorsal colomn/medial lemniscus @ closest to gray matter/lateral
cervical for lateral spinothalamic tract @ closest to grey matter/medial
111
describe the pathway of the dorscal colomn
ascending pressure, vibration, fine touch, proprioception --> first order neron from sensory nerve ending to cell body in the dorsal root ganglion to the spinal cord and ascends ipsilaterally in the dorsal colomn --> synapse 1 at the nucleus cuneatus or gracilis in the medulla --> DECUSSATES int he medulla and ascends contralaterally in the medial lemniscus -- synapse 2 in the VPL of the thalamus - third order neuron to the sensory cortex
112
whats in the anteriorspinothalamic tract
crude touch and pressure
113
describe the spinothalamic tract
ascending: pain and temp from lateral and crude touch and pressure from anterior -- sensory nerve endinds Adelta and C with cell body in dorsal root ganglion - enters spinal core - synapse 1 in the ipsilateral gray matter of spinal cord -- second order decussates and anterior white commissure and ascends contralaterally - to the vpl in the thalamus synapnses - third order to the sensory cortex
114
describe the lateral corticospinal tract
descending - volumtanr movement of contralateral limns
umn with cell body in the primar motor cortex - descends ipsilatreally thorugh the internal capsule - most fibres decussate at cauda medullat - pyramidal decussaiton - descends contralaterally -- synapse one in the cell body of the anterior/ventral/basal horn of the spc - and lower motor neuron leaves the spinal cord to synapse at the NMJ
115
UMN or LMN: clasp knife spasicity
UMN
116
UMN or LMN: everything increased, increased reflexes, increased tone, positive babinsk spasy paralysis
UMN
117
UMN or LMN: everything decrease, decrease reflexes, decreased atone, bo Babinski and flaccid paralysis
LMN
118
UMN or LMN: weakness
both
119
UMN or LMN: atrophy
LMN
120
UMN or LMN: fasciulations
LMN: muscle is freakign out cause its scared and alone with out its neuron
121
c2 dermatome
posterior half of skull cap
122
c3 dermatome
turtle neck region
123
c4
low collar shirt
124
t4 dermatome
nipples
125
t7 dermatome
xiphiod process
126
t10
umbilicus
127
l1
inguinal ligament
128
l4
keecaps
129
s234 dermatome
erection and sensation of penile and anal zones
130
where does referred pain from the diaphragm and gall bladder go
shoulder via phrenic nerves c345
131
biceps reflex pelase
c56
132
triceps reflex please
c78
133
quadriceps reflex please
L34
134
Achilles relfec pelase
S1S2
135
cremaster reflex pelase
L1L2
136
anal wink please
S34
137
what is the nerve root of the biceps reflex
c5
138
what is the nerve root of triceps reflex
c7
139
what is the nerve root of quadriceps refles
l4
140
what is the nerve root of Achilles reflex
S1
141
what are primitive reflexes
present in a healthy infact but are absent in neur intact adult. normally disappear within first year of live. inhibited by develipign frontal lobe
142
what to think about if see primitive reflexes in an adult
frontal lobe damage
143
what is the moro reflex
abduct/extend arms when startled and then draw together
| gone at three mothsn
144
rooting reflex
movement of head towards one side if cheek or mouth is strokes - nipple seeking
gone at four months
145
sucking reflex
sucking response when roof of moth is touched
146
palmar reflex
curling of fingers if plam is stroked
| 6 months
147
plantar reflex
dorsiflexion of large toe and fanning of toehr toes with plantar stimulation
gone at 12 motnhs
if present think UMN lesions
148
gallant reflex
remember Grenadian hospital
stroke alogn one side of spine whil enewborn is in ventral suspension ie face down and will cause lateral flexion fo lower body toward stimulated side
