Brain Flashcards
(172 cards)
1
Q
What is the function unit of the nervous system?
A
the neuron
2
Q
what is the primary role of the neuron?
A
receive and send information
3
Q
what makes up the Gray matter?
A
cell bodies and nonmyelinated axons
4
Q
what makes up white matter?
A
myelinated axons
5
Q
What are the types of neurons in the CNS?
A
Multipolar
Pseudounipolar
Bipolar
6
Q
What kind of neuron is most numerous in the CNS?
A
Multipolar
7
Q
Where are pseudounipolar neurons found?
A
Dorsal root ganglion
Cranial ganglion
8
Q
Where are bipolar neurons found?
A
Retina
Ear
9
Q
What are the functions of the glia cell?
A
-creates a healthy ionic environment
-modulates nerve conduction
-controls reuptake of neurotransmitters
-Repairs neurons after injury
10
Q
what are the types of glial cell?
A
Astrocytes
Ependymal cells
Oligodendrocytes
Microglia
11
Q
What is the function of astrocytes?
A
-most abundant type of glial cell
-regulation of metabolic environment
-repairs neuron after injury
12
Q
what is the function of ependymal cells?
A
-Concentrated in the roof of the 3rd and 4th ventricles and spinal canal
-Form the choroid plexus, which produces CSF
13
Q
what is the function of oligodendrocytes?
A
Form myelin sheath in the CNS
* Schwann cells form myelin sheath in PNS
14
Q
What is the function of Microglia?
A
act as macrophages and phagocytize neuronal debris
15
Q
What do the dendrites do?
A
recieve and process signals
16
Q
what does the presynaptic terminal do?
A
release neurotransmitters
17
Q
what does the axon do?
A
send signals
18
Q
what does the soma do?
A
integrates signals
cellular machinery
19
Q
What structure connects the two cerebral hemispheres?
A
corpus callosum
20
Q
Frontal lobe:
A
contains the motor cortex
21
Q
parietal lobe:
A
contains the somatic sensory cortex
22
Q
occipital lobes:
A
contains the vision cortex
23
Q
temporal lobes:
A
contains the auditory cortex and speech centers
24
Q
where is broca’s area located?
A
- frontal lobe
- motor control of speech
25
where is wernicke's area:
temporal lobe
-understanding speech
26
Parietal lobe:
contains somatic sensory cortex
27
Occipital lobe:
contains vision cortex
28
What is the cerebral cortex responsible for?
cognition, movement (precentral gyrus of the frontal lobe), and sensation (postcentral gyrus of the parietal lobe)
29
what is the hippocampus responsible for?
memory and learning
30
what is the amygdala responsible for?
emotion, appetite, responds to pain and stressors
31
what is the basal ganglia responsible for?
fine control of movement
- caudate nucleus
-globus pallidus
32
What makes up the Diencephalon?
-Thalamus
-Hypothalamus
33
What does the thalamus do?
-acts as a relay station that directs information to various cortical structures
34
what does the hypothalamus do?
Primary neurohumoral organ
35
what parts make up the brainstem?
-Midbrain
-Pons
-Reticular activating system
-Medulla
36
What does the midbrain do?
auditory and visual tracts
37
what does the pons do?
autonomic integration
38
what does the reticular activating system do?
controls consciousness, arousal, and sleep
39
what does the medulla do?
autonomic integration
40
what makes up the cerebellum?
-archicerebellum
-paleocerebellum
-neocerebellum
41
what does the archicerebellum do?
maintains equillibrium
42
what does the paleocerebellum do?
regulates muscle tone
43
what does the neocerebellum do?
coordinates voluntary muscle movement
44
What is the pneumonic for the cranial nerve names?
On Occassion Our Trusty Truck Acts Funny Very Good Vehicle Any How
45
What is the pneumonic for the functions of the cranial nerves?
Some Say Marry Money But My Brother Says Bad Business to Marry Money
46
Cranial nerve 1:
Olfactory
Sensory
Smell
47
CN 2:
Optic
Sensory
Vision
48
CN 3:
Oculomotor
Motor
eye movement, pupil constriction
49
CN 4:
Trochlear
Motor
eye movement
50
CN 5:
Trigeminal
V1-ophthalamic
V2- maxillary
V3- mandibular
Both
Somatic sensation to the face, somatic sensation to anterior 2/3 tongue, muscles of mastication
51
CN 6:
Abducens
Motors
eye movement
52
CN 7:
Facial
-temporal, zygomatic, buccal, mandibular, cervical
both
Facial movement except mastication, eyelid closing, taste to anterior 2/3 of tongue
53
CN 8:
Vestibulocochlear
Sensory
Hearing and balance
54
CN 9:
Glossopharyngeal
Both
somatic sensation and taste to posterior 1/3 of tongue
55
CN 10:
Vagus
Both
Swallowing
56
CN 11:
Accessory
Motor
Shoulder shrug
57
CN 12:
Hypoglossal
Motor
tongue movement
58
Which Cranial nerves are a part of the peripheral nervous system?
All except CN 2 (optic)
59
Which CN is the only one surrounded by dura?
CN 2 (optic)
60
What generates excruciates neuropathic pain in the face?
Tic douloureux (Trigeminal neuralgia CN 5)
61
What cranial nerves control eye movement?
3 (oculomotor)
4 (trochlear)
6 (abducens)
62
what is the mnemonic for the 5 branches of the facial nerve? (CN 7)
Two Zebras Bit My Carrot
temporal, zygomatic, buccal, mandibular, cervical
63
Bell's Palsy results from injury to which CN?
CN 7 - Facial
- causes ipsilateral facial paralysis
64
Parasympathetic output is carried by which cranial nerves?
3 (oculomotor), 7 (facial), 9 (glossopharyngeal), 10 (vagus)
65
Which CN is responsible for 75% of all parasympathetic activity?
CN 10 (Vagus)
66
Which CN is part of the CNS?
CN 2 optic
67
what does the CSF do?
cushions the brain, provides buoyancy, delivers optimal conditions for neurologic function
68
where is CSF located?
right lateral ventricle, left lateral ventricle, 3rd ventricle, 4th ventricle, subarachnoid space in brain and spinal cord
69
What does the blood-brain barrier do?
separates CSF from plasma
70
where is the BBB NOT present?
-Chemoreceptor trigger zone
-Hypothalamus
-Pineal gland
-Posterior pituitary gland
-Choroid plexus
does not have carrier proteins
poorly developed in the neonate
71
What is the normal CSF volume?
150 mL
72
what is the specific gravity of CSF?
1.002-1.009
73
What produces CSF?
ependymal cells of the choroid plexus
74
what is the rate of CSF production?
30 mL/hr
75
What is the normal CSF pressure?
5-15 mmHg
76
what is the site of CSF production?
choroid plexus in ventricles
77
what is the site of CSF reabsorption?
arachnoid villi in superior sagittal sinus
78
what is the rate of CSF reabsorption dependent on?
the pressure gradient btwn the CSF and venous circulation.
79
CSF circulation
1.) left and right lateral ventricle
2.) Foramen of Monro (interventricular foramen)
3.) 3rd ventricle
4.) Aqueduct of Sylvius (cerebral aqueduct)
5.) 4th ventricle
6.) Foramen of Luschka
7.) Foramen of Magendie
8.) subarachnoid space
80
What is the Mnemonic for CSF flow in the brain?
Love My 3 Silly 4 Lorn Magpies
lateral ventricles
Monro
3rd ventricle
Sylvius
4th ventricle
Luschka
Magendie
81
What is hydrocephalus?
excessive accumulation of CSF in the brain. Can increase ICP.
82
What are the 2 types of hydrocephalus?
1.) obstructive hydrocephalus
2.) Communicating hydrocephalus
83
What is obstructive hydrocephalus?
obstruction to CSF flow in the ventricular system (most common)
84
What is communicating hydrocephalus?
-Decreased CSF absorption by the arachnoid villi (intracranial hemorrhage)
-Overproduction of CSF (rare)
85
what is the calculation for cerebral blood flow?
CBF= CPP/Cerebral vascular resistance
86
what is global CBF?
45-55ml/100g/min or 15% of CO
87
what is cortical CBF?
75-80mL/100g/min
88
What is subcortical CBF?
20ml/100g/min
89
what are the critical thresholds for global CBF?
-20ml/100g/min= ischemia
-15ml/100g/min= cortical suppression
-<15ml/100g/min= membrane failure and cell death
90
what are the 5 determinants of CBF?
1.) CMRO2
2.) Cerebral perfusion pressure
3.) PaCO2
4.) PaO2
5.) venous pressure
91
what factors decrease CMRO2?
-hypothermia
-halogenated anesthetics
-propofol
-etomidate
-barbs
92
what factors increase CMRO2?
-hyperthermia
-seizures
-ketamine
-nitrous oxide
93
What is a normal CMRO2?
3-3.8ml/o2/100g/min
94
60% of CMRO2 is used for?
electrical activity
95
40% of CMRO2 is used for?
40% cellular integrity
96
CMRO2 decreases by _____% for every ____ degrees C decrease in temp
cmro2 decreases by 7% for every 1 degree C decrease in temp
97
EEG suppression occurs at _____degrees C
18-20 degrees C
98
at what Degree C denatures proteins and destroys neurons?
42 degrees
99
Between what Cerebral perfusion pressures is CBF autoregulated?
50-150 mmHg
or MAP of 60-160
100
Are cerebral vessels MAX DILATED when CPP is high or low?
LOW (50mmhg)
101
Are cerebral vessels MAX constricted when CPP is high or low?
HIGH (150mmhg)
102
What are 3 things that decrease the effectiveness of autoregulation?
1.) intracranial tumor
2.) head trauma
3.) volatile anesthetics
103
How does chronic systemic HTN affect the cerebral autoregulation curve?
pts w chronic systemic HTN are at greater risk of cerebral ischemia when they become hypotensive
104
At a PaCo2 of 40mmhg what is global CBF?
50mL/100g/min
105
for every 1 mmHg INCREASE in paco2, CBF will?
INCREASE by 1-2mL/100g/min
106
for every 1 mmhg DECREASE in paCO2, CBF will?
DECREASE by 1-2mL/100g/min
107
At what PaCO2 does maximal vasodilation occur at?
80-100 mmhg
108
at what paco2 does maximal vasoconstriction occur at?
25 mmHg
109
theres a _____ relationship btwn paco2 and CBF
LINEAR
110
what does a decrease CSF pH do to CBF?
INCREASE (resp acidosis)
111
what does an increased CSF pH do to CBF?
DECREASE (resp alkalosis)
112
What is steal phenomena?
situations that cause cerebral vasodilation (hyoercapnia, hypoventilation, vasodilator) vasodilate the vessels that supply healthy brain tissue. As a result this "steals" flow from ischemic areas
113
what is inverse steal or the Robinhood effect?
Using hyperventilation to constrict vessels that supply healthy brain tissue. Flow will be redistributed to ischemic regions.
114
a Pao2 below ______ causes cerebral vasodilation and increases CBF?
50-60mmHg
115
what conditions impair venous drainage?
jugular compression
increase intrathoracic pressure (coughing/PEEP)
vena cava thrombosis
vena cava syndrome
116
Signs of intracranial HTN
-headache
-N/V
-papilledema (swelling of optic nerve)
-pupil dilation and non-reactivity to light
-focal neurologic deficit
-seizure
-coma
117
What is the monro-kellie doctrine?
describes the pressure -volume equillibrium btwn brain, blood and CSF
and increase in one must be compensated with a decrease in another
118
What is Cushings Triad?
HTN
Bradycardia
irregular respirations
increased ICP = decreased CPP. To preserve CPP BP increases. HTN activates baroreceptor reflex leading to bradycardia. Compression of the medulla causes irregular resps.
119
What is the most common site of herniation?
most common site of transtentorial herniation is at the temporal uncus
affects CN 3 (ocluomotor) = fixed and dilated pupils
120
The effects of hyperventilation lasts how long?
6-20 hrs bc the pH of the CSF equilibrates with Paco2.
121
which drugs reduce CSF production?
Acetazolamide and lasix
122
MOA of mannitol in reducing ICP
Cerebral Mass/Edema reduction
123
MOA of corticosteroids in reducing ICP
Cerebral edema reduction
124
what role does hyperventilation play in reducing ICP?
Cerebral blood volume reduction
125
MOA of acetazolamide in reducing ICP
CSF reduction
126
MOA of propofol in reducing ICP
Cerebral blood volume reduction
127
How does maintaining neck neutrality reduce ICP?
Cerebral blood volume reduction
128
The following vascular structures exist as pairs EXCEPT:
a.) posterior communicating artery
b.) vertebral artery
c.) basilar artery
d.) middle cerebral artery
c.) basilar artery
129
what supplies the anterior cerebral arterial circulation:
The Internal carotid artery (ICA) supplies the anterior circulation
130
where do the ICAs enter through?
foramen lacerum
131
what supplies the posterior cerebral arterial circulation?
the vertebral arteries
132
where do the vertebral arteries enter through?
foramen magnum
133
what is the anterior circulation?
Aorta
Carotid artery
Internal Carotid artery
Circle of Willis
Cerebral Hemispheres
134
what is the posterior circulation?
Aorta
Subclavian artery
Vertebral Artery
Basilar artery
Posterior fossa and cervical spinal cord
135
what is the function of the Circle of Willis?
provide redundancy of blood flow through the brain
136
What sinuses do the venous blood from the cerebral cortex and cerebellum drain through?
superior sagittal sinus and dural sinuses
137
Venous blood from the basal brain structures drain via which sinuses?
inferior sagittal sinus
vein of Galen
straight sinuses
138
How does all venous blood exit the brain?
via the jugular veins
139
What kind of stroke is most common?
ischemic
140
what are the risk factors for a stroke?
-HTN (most important)
-Smoking
-DM
-Hyperlipidemia
-excessive alcohol intake
-elevated homocysteine level
141
What is the first line tx for ischemic stroke?
PO ASA
142
within what time frame can TPA be given?
4.5 hrs
143
Within what timeframe can an embolectomy be performed for large vessel occlusion?
6 hrs.
144
What is triple H therapy for vasospasm?
Hypervolemia
Hypertension
Hemodilution (HCT 27-32%)
144
What is the formula for transmural pressure?
MAP-ICP
145
When is a vasospasm most likely to occur?
4-9 days
146
what is the gold standard for diagnosis of vasospasm?
cerebral angiography
147
what is a medication that can be used for vasospasm?
Nimodipine
refractory vasospasm:
-verapamil
-nicardipine
-papaverine
-milrinone
balloon angioplasty
148
What is cerebral salt-wasting syndrome?
Hyponatremia is most commonly a result of CSW. The brain releases natriuretic peptide and this leads to volume contraction, hyponatremia, and sodium wasting by the kidneys
149
what is the treatment for CSW?
isotonic crystalloids
150
what are the 2 most common signs of vasospasm?
new neurologic deficit
altered level of conciousness
151
What do you give to reverse Warfarin?
-FFP
-Prothrombin complex concentrate
-recombinant factor 7a
152
what do you give to reverse ASA/clopidgrel?
Platelets
recombinant factor 7
153
what kind of fluids do you wanna give for TBI?
Hypertonic saline
154
what receives a 1 for motor, verbal and eye response for GCS?
no motor reponse
no verbal response
no eye opening
155
what receives a 2 for motor verbal and eye response for GCS?
extension to pain
incomprehensible sounds
open to pressure/pain
156
what receives a 3 for motor, verbal and eye response for GCS?
flexion to pain
inappropriate words
opens eyes to sound
157
what receives a 4 for motor, verbal and eye response for GCS?
withdraws to pain
confused
spontaneously opens
158
what receives a 5 for GCS?
localizing response to pain
oriented
159
what receives a 6 on the GCS?
obeys commands
160
What is a jacksonian march?
a partial seizure that progresses to a generalized seizure
161
what is the acute tx for a grand mal seizure?
propofol
diazepam
thiopental
vagal nerve stimulator
162
What is status epilepticus?
Seizure activity that lasts longer than 30 mins or 2 grand mal seizures where consciousness is not regained in btwn.
163
what is the treatment for status epilepticus?
phenobarbital
thiopental
phenytoin
benzos
propofol
164
What does a seizure look like under general anesthesia?
tachycardia
HTN
increased Etco2
165
what 3 drugs are useful for locating seizure foci during cortical mapping?
etomidate
methohexital
alfentanil
166
Which meds have the mechanism of action of blocking the voltage-gated sodium channels to produce membrane stabilization?
phenytoin
valproic acid
carbamazepine
167
what is the mechanism of action of gabapentin?
Inhibits the alpha 2-delta subunit of voltage-gated calcium channels in the CNS
168
Which anticonvulsants do NOT induce hepatic enzymes?
Gabapentinoids
169
do gabapentinoids produce resp depression?
they can exacerbate resp depression when combined w an opioid
170
What are some side effects of phenytoin?
-dysrhythmias/hotn
-gingival hyperplasia
-aplastic anemia
-cerebellar-vestibular dysfunction
-steven-johnson syndrome
-birth defects
171
the duration of action of which drug will be prolonged in the patient treated w donepezil for Alzheimer's disease?
a.) roc
b.) vec
c.) succs
d.) cis
c.) succs
