Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neurosurgery Board Review > 2. Neurophysiology > Flashcards

2. Neurophysiology Flashcards

1
Q

How does Mg prevent excitotoxicity in brain?

A

Blocks Ca and NMDA channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Most abundant excitatory neurotransmitter in the brain?

A

Glutamate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cellular elements of BBB

A

Endothelial cells
Astrocyte endfeet
Pericyte

Capillary endotheilal cells connected by tight junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Platelet function after SAH?

A

Enhanced leading to increased platelet aggregation in cerebral microcirculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cerebral blood flow immediately after SAH?

A

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is GPIIb/IIIa?

A

Platelet surface integrin - mediator of platelet aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Dense granules of platelets?

A

5HT, ATP, PDGF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Disturbed balance of which peptide contributes to vasospasm?

A

Endothelin 1 (vasoconstriction) and nitric oxide (vasodilation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Superoxide and hydrogen peroxide generates highly reactive hydroxyl radical - name?

A

Haber-Weiss reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mechanism of steroid treatment in blunt spinal cord injury?

A

Local blood flow, inhibition of immunologic injury, and free radical-mediated lipid peroxidation and neuronal damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is S100B?

A

Calcium binding protein abundant in astrocytes - may be neuroprotective/neurotrophic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Windkessel phenomenon?

A

Cerebral vasculature expand and ability of CSF/venous blood to translocate to accomodate arterial pulsations and provide smooth capillary flow in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Ischemic penumbra?

A

Region where cerebral blood flow reduction has passed threshold that leads to failure of electrical but not membrane function - structurally intact, but functionally disturbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Role of infiltration with local anesthetic at beginning of a case?

A

Prevents activation of nociceptors during surgery and lessens need for analgesics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Structural unit of gap junction

A

Connexon allows direct electrical communication between cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Functions of TGF beta?

A

Development/progression of brain tumors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What enzyme is inhibited by acetazolamide?

A

Carbonic anhydrase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Difference between bioactive Guglielmi detachable coil (GDC) and platinum GDC?

A

Bioactive coil accelerates clot and promotes development of mature connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Mutation in Crouzon syndrome

A

Fibroblast growth factor receptor 2 - absence of ligand binding - premature fusion of cranial sutures leading to abnormal cranium shape, restricted growth and increased ICP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Baclofen mechanism?

A

GABA agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hyparrhythmia

A

Chaotic, high amplitude EEG (Infantile spasm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Subsidence?

A

Loss of vertebral column heigh with aging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Genetic defect in Gorlin syndrome?

A

autosomal dominant

Mutation of PTCH gene that predisposes to neoplasias and widespread congenital malformations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Water channel proteins of the brain?

A

Aquaporins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Most common agent for pharmacologic dilatation of vasospastic cerebral vessels?
Papaverine hydrochloride - endothelium-independent smooth muscle relaxant
26
How do intervertebral disks receive nutrition?
Passive diffusion from capillary beds in subchondral endplate region of vertebral body
27
Composition of PEEK cage
Polyetheretherketone (PEEK) spacers - strong polymer that withstand compressive load of vertebral column
28
Common areas of leptomeningeal dissemination for tumors
Basilar cisterns, sylvian fissure, cauda equina (gravity and slower rate of CSF)
29
Resting membrane potential in myelinated pheripheral nerves? in soma?
~ 90 mV and ~ 65 mV | Determined by K+ (100x more permeable than Na+)
30
Botulinum toxin mechanism
Inhibit release of ACh from presynaptic terminal
31
Where do AP in neurons start?
``` Axon hillock (7x more voltage-gated Na channels there) - depolarize much easier than soma ```
32
Factors that determine velocity of propagation of AP
Inverse of internal resistance Inverse of membrane capacitance Proportionate by transmembrane resistance Myelin increases resistance/decreases capacitance
33
Conduction velocity of small unmyelinated and large myelinated nerves?
0.5 m/s | 120 m/s
34
How does hypocalcemia lead to tetany?
Less Ca2+ in interstitial fluid, Na+ open sooner - lower threshold of membrane depolarization
35
How does hyperventilation lead to seizure?
Respiratory alkalosis (increase pH) -> increase membrane excitability and induce seizure
36
How big is a synaptic cleft
20-30nm
37
What is unique about synthesis of neurotransmitter NE?
Synthesized within vesicle by dopamine alpha-hydroxylase (dopamine to NE)
38
2 types of ACh receptors
1. Nicotinic (NMJ, preganglionic endings of both sym and parasym fibers) 2. Muscarinic - postgan parasympathetic and postganglionic sympathetic of sweat glands
39
2 main inhibitory neurotransmitters of CNS
GABA and glycine
40
GABA receptor mechanism
5 subunit with central Cl- channel - causes hyperpolarization
41
Which body part has largest area of representation in primary somatosensory area?
The lips
42
What is hyperalgia
Increased sensitivity to pain | increased sensitivity of receptors, facilitation in spinal cord or thalamic lesion
43
Thalamic pain syndrome?
Dejerine-Roussy syndrome | Posteroventral thalamic stroke and abnl facilitation of medial thalamic nucleus.
44
Hangover pain?
Chemical irritation to meninges
45
What causes night blindness?
Severe deficiency in vitamin A - decrease amount of photosensitive pigment to detect decreased light. Tx: IV infusion of vitamin A
46
Where in retina has only cones?
Fovea (center of macula)
47
What is scotoma?
Area of decreased vision surrounded by preserved vision in visual field
48
Where on tongue is salty taste detected?
Tip
49
1st order neuron of olfactory pathway located
Olfactory cells in olfactory epithelium. | These bipolar cells send axons through cribiform plate to olfactory bulb.
50
Which protein is involved in retrograde and fast anterograde transport?
Kinesis and dynein
51
What does muscle spindle detect?
Length and velocity of change in length of muscle, stimulated by stretching. Increases firing with muscle stretch and decreases firing with muscle contraction.
52
What carries info from muscle spindles and golgi tendon organ
Dorsal spinocerebellar tracts
53
What cause decerebrate rigidity
Lesion between pons and midbrain - blocks input to medullary reticular formation from red nucleus/BG/cortex - unopposed antigravity muscle tone that is stimulated by lateral vestibular nucleus and pontine reticular nucleus.
54
In vestibular system, what is sensory orga of utricle and saccule?
Macula that contains hair cells that have cilia embedded in gelatinous layer containing calcium carbonate otoliths.
55
What is the sensory organ of semicircular canals?
Crista ampullaris - which has hair cells with cilia that project into cupula (gel cup)
56
In the vestibular system, the utricle has its macula in which plane?
Utricle has macula on horizontal plane (sense acceleration direction when upright). Saccule has macula in vertical plane (acceleration in horizontal or supine).
57
Mechanism of action of nitrosoureas
Alkylating agents for malignant brain tumors - cause crosslinks of DNA and breakage
58
Mechanism of temozolomide
Attach methyl group to DNA base guainine - prevents proper DNA replication
59
What is MGMT (O6-methylguanine-DNA methyltransferase)?
DNA repair enzyme that remove methyl group placed by temozolomide (low levels respond better to temozolomide)
60
EEG during REM sleep?
Beta waves (same as awake)
61
Effect of sleep deprivation on autonomic system
Increase sympathetic and decrease parasympathetic
62
Hering-Breuer inflation reflex
Over distension of lungs - stretch receptors in bronchi/bronchioles through vagus nerve inhibits dorsal resp nucleus in dorsal medulla to stop inspiration
63
Atonic bladder
Flaccid bladder - fails to empty properly, causing overflow incontinence - overaccumulation cause micturition reflex.
64
What causes vasogenic edema?
Increased BBB permeability (extracellular) - caused by vessel damage and inflammation.
65
What causes cytotoxic edema?
Impaired Na/K pump in ischemia. Water/electrolytes accumulate in cells (intracellular type edema)
66
Ischemic optic neuropathy - visual fields?
Painless monocular blindness by occlusion of central retinal artery - altitudinal field deficit.
67
Mechanism of clopidogrel (plavix)?
Selective inhibitor of platelet aggregation - irreversibly to ADP receptor on platelet cell membranes - block glycoprotein 2b/3a pathway. Stop at least 1 week before surgery.
68
Antidote for arsenic poisoning
Dimercaprol (BAL) - British Anti-Lewisite)
69
What medications increase levels of dilantin?
Cimetidine, coumadin, INH, sulfa drugs
70
Red man's syndrome
Rapid infusion of vancomycin - histamine release producing facial flushing, pruritis, hypotension
71
Effect of fentanyl on cerebral blood flow?
Decreases
72
Effect of ketamine on cerebral blood flow?
Increases
73
Causes of hypercortisolism (Cushing syndrome)
Iatrogenic, ACTH-secreting pituitary adenoma, adrenal tumor, ectopic ACTH (pulmonary oat cell tumor or carcinoid)
74
Cause of febrile nonhemolytic transfusion reactions
Antibodies to donor WBC (treat with acetaminophen)
75
Acute hemolytic transfusion reaction
Within minutes - fever, dyspnea, chest pain, hypotension. Can have DIC and multiple organ failure.
76
1 unit of platelets increases platelet count by how much?
5000-10,000 and lasts for 1 week
77
Malignant hyperthermia tx
Dantrolene
78
Ideomotor apraxia
Cannot perform complex motor task but aware of task | Lesion of supramarginal gyrus of dominant parietal lobe
79
Factors causing O2 right shift
Decrease O2 affinity | Increase H+, CO2, temp, 2-3 DPG
80
Types of sensory axons
``` Group 1 (A alpha) Group 2 (A beta, A gamma) Group 3 (A delta) ```
81
Group 1 sensory axons
A alpha - largest, fastest conducting | Afferents of muscle spindles, 1b fibers - afferents from Golgi tendon organs
82
Group 2 sensory axons
A beta and gamma - slower | Muscle spindles and cutaneous touch/pressure
83
Group 3 sensory axons
A delta - smaller and slower; carry temp, light touch, sharp pain
84
Group 4 sensory axons
C fibers - slowest fibers and mediate temp and burning pain.
85
Basic types of striated muscle fibers
3 Basic 1. Type I 2. Type IIa 3. Type IIb
86
Type I muscle fibers
slow-twitch or red fibers; lots of mitochondria. Prolonged contraction without fatigue
87
Type IIA muscle fibers
fast fatigue-resistant - can maintain for several minutes
88
Type IIB muscle fibers
fast fatigable fibers - lots of glycogen and anaerobic metabolism. Cannot sustain contraction forces from rapid accumulation of lactic acid
89
Mechanism of TCA
Block reuptake of 5HT and NE
90
Mechanism of cholera and pertusis toxin
stimulate cAMP inside cell Cholera stimulates Gs Pertusis inactivates Gi
91
NO generated from which amino acid?
Arginine (from nitric oxide synthase)
92
Sarcomere - which region gets shorter during contraction
H zone and I band
93
Receptive fields of bipolar cells vs neurons of primary visual cortex
Bipolar cells - circular receptive field | Neurons - rectangular receptive fields
94
Which stage of sleep do night terrors occur?
Stage 3-4 (deep sleep)
95
Too rapid correction of hyponatremia
Central ponteine myelinolysis (no more than 0.5mEq/L/h) Dissolution of myelin sheaths of fibers within central aspect of basis pontis - spastic quadriparesis, pseudobulbar palsy, acute MS changes
96
What should be prescribed for patient with coagulopathy associated with coumadin?
Vitamin K and FFP
97
What is Apo E gene?
Apo E made in astrocytes for lipid transport in brain | E4 assoc. with age-related cognitive impairment.
98
How is achondroplasia inherited?
Autosomal dominant, but may be sporadic. | Mutation in transmembrane region of FGFR3 (neg control of bone formation)
99
What is CRP?
Acute phase reactant in response to injury or infection, made in liver or adipocytes. Highest POD2 and subsides at POD5
100
What does STIR stands for in MRI?
Short tau inversion recovery
101
What age do K-complexes begin to appear in sleep cycle?
6 months
102
When in sleep cycle do K-complexes appear?
Stage 2 of NREM

Neurosurgery Board Review (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions