HY Questions Flashcards
1
Q
What proteins compose gap junctions that form electrical synapses between neurons?
A
- Connexons.
2
Q
What second messenger is involved with all norepinephrine receptors?
A
- cAMP.
3
Q
What enzyme is responsible for the degradation of cAMP?
A
- Phosphodiesterase.
4
Q
Which muscle spindle afferent fibers transmit information about muscle contraction velocity?
A
- Ia afferent fibers.
5
Q
What is the response of Golgi tendon organs to muscle contraction?
A
- Marked increase in firing rate.
6
Q
What ion is primarily responsible for resting membrane potential in neurons and glia?
A
- Potassium.
7
Q
Where are the cell bodies of olfactory neurons located?
A
- Olfactory epithelium.
8
Q
What is the MOA of Baclofen?
A
- GABA-B agonist.
9
Q
What is the only sensory modality to bypass the thalamus?
A
- Smell.
10
Q
What enzyme generates diacylglycerol?
A
- Phospholipase C.
11
Q
What causes the miniature end-plate potential?
A
- The spontaneous release of one quanta of ACh.
12
Q
What is the mechanism of action of tricyclic antidepressants?
A
- They block reuptake of NE and 5-HT.
13
Q
What is responsible for the BBB?
A
- Tight junctions between endothelial cells.
14
Q
Which circumventricular organ has an intact BBB?
A
- The subcommissural organ.
15
Q
What ion is responsible for the initial depolarization of cochlear hair cells?
A
- Potassium.
16
Q
What obstructs the NMDA channel pore at resting membrane potential?
A
- Magnesium.
17
Q
What initiates contraction in smooth muscle?
A
- Calcium-calmodulin activation of myosin light chain kinase.
18
Q
What is the rate limiting enzyme in dopamine synthesis?
A
- Tyrosine hydroxlyase.
19
Q
What is the function of myelin?
A
- It increases transmembrane resistance and decreases membrane capacitance.
20
Q
What drug blocks voltage-gated Na channels?
A
- Tetrodotoxin.
21
Q
What is the function of the macula of the utricle?
A
- Detect linear acceleration in the horizontal plane.
22
Q
What is the shape of the receptive fields of primary visual cortex neurons?
A
- Rectangular.
23
Q
Fibers from the ipsilateral retina synapse in which layers of the lateral geniculate body?
A
- 2, 3, and 5.
24
Q
What nerve fibers mediate the sensation of sharp pain?
A
- A-delta.
25
What protein mediates fast anterograde axonal transport?
1. Kinesin.
26
What is the primary target of dentate nucleus efferent fibers?
1. VL nucleus of the thalamus.
27
What are the most excitatory fibers of the CNS?
1. Climbing fibers.
28
What is the neurotransmitter of the Renshaw cell?
1. Glycine.
29
What type of receptors are present on the Renshaw cell?
1. Muscarinic cholinergic receptors.
30
How do you differentiate a femoral neuropathy from a lumbar plexopathy?
1. Hip adduction will be preserved in the former and absent in the latter.
31
What is the only output of the cerebellar cortex?
1. The Purkinje cell.
32
What nerve is compressed in the tarsal tunnel?
1. Posterior tibial nerve.
33
What structure contains the highest levels of substance P in the brain?
1. The substantia nigra.
34
What structures are connected by the stria medullary thalami?
1. The septal nuclei and the habenular nuclei.
35
What cranial nerve contains the nodosal ganglion?
1. The vagus nerve.
36
Where do SVA fibers synapse in the brainstem?
1. The nucleus of the solitary tract (gustatory nucleus).
37
Where do the frontopontine fibers travel in the internal capsule?
1. The anterior limb.
38
What nerve is compressed by Struther's ligament?
1. The median nerve.
39
Where is the posterior interosseus nerve often entrapted?
1. At the supinator (arcade of Frohse).
40
Where do GVA fibers traveling in Hering's nerve synapse?
1. The inferior aspect of the solitary tract.
41
When does the posterior neuropore close?
1. Post-ovulatory day 26.
42
Where do first-order sympathetic neurons to the pupillary dilator originate?
1. The hypothalamus.
43
Where is the cortical area for macular vision located?
1. Occipital poles.
44
Where is the first site of binaural convergence in the auditory pathway?
1. The superior olives.
45
What structures pass through the annulus of Zinn?
1. CN II, III, VI, the ophthalmic artery and the nasociliary nerve.
46
Where do preganglionic parasympathetic fibers destined for the lacrimal glands synapse?
1. The pterygopalatine ganglion.
47
What innervates the cricothyroid?
1. The superior laryngeal nerve (of CN X).
48
What fibers travel in the juxtarestiform body?
1. Vestibulocerebellars and cerebellovestibulars.
49
What region of primary somesthetic cortex do muscle spindles project?
1. 3a.
50
What artery perfuses the retrolenticular internal capsule?
1. The anterior choroidal artery.
51
What is the 5-year stroke risk of asymptomatic 80% carotid artery stenosis?
1. 16.5% (3.3% per year x 5 years).
52
What gene is responsible for Duchenne muscular dystrophy?
1. Dystrophin (Xp21).
53
What cranial nerve is most commonly involved in neurosarcoidosis?
1. CN VII.
54
What is the most common cause of aseptic (viral) meningitis?
1. Enteroviruses.
55
What lesions result in downbeat nystagmus?
1. Lesions of the cervicomedullary junction.
56
What intestinal disease is associated with a hypercoagulable state?
1. Ulcerative colitis.
57
What is the most common cause of occult spinal dysraphism?
1. Spinal lipoma.
58
Maternal hyperglycemia is a risk factor for which spinal developmental disorder?
1. Caudal regression syndrome.
59
Trisomy 13 or 18 is associated with what developmental anomaly of the brain?
1. Holoprosencephaly.
60
What neurodegenerative disorder is associated with pre- and postcentral gyrus atrophy and focal arm dystonia?
1. Corticobasal degeneration.
61
What chromosome is abnormal in Huntington's disease?
1. Chromosome 4.
62
What gene is abnormal in spinobulbar muscular atrophy (Kennedy's disease)?
1. The androgen receptor gene (X chromosome).
63
What neurocutaneous syndrome is associated with sphenoid dysplasia and optic gliomas?
1. NF-1.
64
What is the inheritance pattern of Sturge-Weber syndrome?
1. Sporadic.
65
What neurocutaneous syndrome often presents with epistaxis?
1. Hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease).
66
What HLA allele is associated with multiple sclerosis?
1. DR2.
67
What abnormal compound accumulates in patients with metachromatic leukodystrophy?
1. Sulfatide.
68
What GI tract infection is associated with the development of Guillain-Barre syndrome?
1. Campylobacter jejuni infections.
69
What stage of sleep is associated with night terrors?
1. Stages 3 and 4 (deep sleep).
70
What disorders are associated with incremental responses on repetitive nerve stimulation studies?
1. Presynaptic disorders of the neuromuscular junction (Lambert-Eaton syndrome and botulism).
71
What are the EEG findings of infantile spasms (West syndrome)?
1. Hypsarrythmia.
72
What is the most common pathogen associated with cerebral abscesses?
1. Streptococcus milleri.
73
What is the treatment of choice for toxoplasmosis in AIDS patients?
1. Pyrimethamine and sulfadiazine.
74
What arterial occlusion results in alexia without agraphia?
1. Dominant PCA.
75
What arterial occlusion is classically associated with lateral medullary infarction (Wallenberg's syndrome)?
1. PICA.
76
What tumor exhibits desmosomes and is vimentin positive?
1. Meningioma.
77
What intracranial tumor is associated with polycythemia?
1. Hemangioblastoma.
78
What is the inheritance pattern of familial cavernomas?
1. Autosomal dominant.
79
What differentiates pituitary hyperplasia from a pituitary adenoma?
1. The presence of reticulin with pituitary hyperplasia.
80
What is the composition of the Lewy body?
1. Ubiquitin, alpha synuclein, alphaB crystallin, and neurofilaments.
81
What chromosome is abnormal in Huntington's disease?
1. Chromosome 4.
82
What enzyme is deficient in Gaucher's disease?
1. Glucocerebrosidase.
83
What is the most common isolate from cerebral abscesses?
1. Streptococcus milleri.
84
What leukodystrophy involves the subcortical U fibers and results from deficiencies of the enzyme aspartoacylase?
1. Canavan's disease.
85
What allele is commonly associated with multiple sclerosis?
1. HLA DR2.
86
What type of closed head injury often affects the splenium of the corpus callosum?
1. DAI.
87
What cranial nerve is most commonly involved with neurosarcoidosis?
1. CN VII.
88
What type of CNS tumor is associated with syncytiotrophoblasts?
1. Choriocarcinoma.
89
What type of CNS tumor exhibits "stag horn" vasculature?
1. Hemangiopericytoma.
90
What is the most common chromosomal abnormality in meningiomas?
1. Monosomy 22.
91
What CNS tumor is often associated with prominent granulomatous inflammation?
1. Germinoma.
92
What is the most common chromosomal abnormality in GBM?
1. Gains of chromosome 7 or 20.
93
What is the most common molecular abnormality in GBM?
1. Allelic loss of 10p and 10q.
94
What disorder exhibits ballooned neurons and atrophy of the pre- and postcentral gyri?
1. Corticobasal degeneration.
95
What is the appearance of an acute intracerebral hematoma on T2WI?
1. Markedly hypointense to surrounding brain.
96
What is the most common location of a spinal meningioma?
1. Thoracic spine.
97
What is the most common location of choroid plexus papillomas in children?
1. The lateral ventricles.
98
What tumor has signal characteristics that are similar to CSF on T1 and T2 but also often exhibits increased signal on DWI?
1. Epidermoid.
99
What is the most common location for spinal cellular ependymomas?
1. Intramedullary in the cervical spinal cord.
100
What is the most common chromosomal abnormality in meningiomas?
1. Monosomy 22.
101
What intramedullary spinal cord tumor is associated with NF-2?
1. Ependymoma.
102
What is the only non-enhancing intraventricular tumor?
1. Subependymoma.
103
What is the mechanism of injury in Hangman's fractures?
1. Hyperextension.
104
What blood vessel is most commonly responsible for compression of the trigeminal nerve with trigeminal neuralgia?
1. Superior cerebellar artery.
105
What is the method activity of BCNU?
1. DNA alkylating agent.
106
What is the primary contraindication to the surgical treatment of Parkinson's disease?
1. No significant response to prior medical therapy with L-dopa.
107
What is the treatment of choice for chronic, intractable brachial plexus avulsion pain?
1. DREZ lesioning.
108
What is the most common mechanism of injury in patients with odontoid fractures?
1. Hyperflexion injuries.
109
What type of spinal AVM consists of a dural AV fistula and often presents with chronic neurological deterioration secondary to venous hypertension?
1. Type 1.
110
What is the surgical treatment of choice in children with frequent atonic seizures that are refractory to medical therapies?
1. Corpus callosotomy.
111
What basal cisterns contain portions of the basal vein of Rosenthal?
1. The ambient and crural cisterns.
112
What structure separates the facial nerve from the superior vestibular nerve?
1. Bill's bar.
113
What structure separates the chiasmatic cistern from the interpeduncular cistern?
1. Liliequist's membrane.
114
What cranial nerve palsy is associated with Gradenigo's syndrome?
1. CN VI.
115
What is the most common cause of malignant cerebral edema within 24 hours of the initial closed head injury in the pediatric population?
1. Hyperemia.
116
What is unique about distal anterior cerebral artery aneurysms?
1. They commonly result from trauma against the falx or are mycotic in nature.
117
What is the annual hemorrhage risk of intracranial AVMs?
1. 3-4 %.
118
Where is the mosts common intracranial location for dural AV fistulas?
1. Along the transverse sinus.
119
What feature of dural AV fistula necessitates treatment?
1. The presence of retrograde cortical venous drainage.
120
What is the inheritance pattern for familial cavernomas?
1. Autosomal dominant.
121
What cranial nerves are susceptible to injury during carotid endarterectomy?
1. The hypoglossal nerve and the marginal mandibular branch of the facial nerve.
122
What familial syndrome is associated with pituitary adenomas?
1. Multiple endocrine neoplasia type 1.
123
What is the most common pineal region tumor in children?
1. Germinoma.
124
What is the most common pattern of hearing loss in patients with acoustic neuromas?
1. High frequency sensorineural hearing loss.
125
What level is most commonly involved with degenerative isthmic spondylolisthesis?
1. L4-5.
126
What approach is associated with the highest morbidity in the treatment of thoracic disc herniations?
1. Dorsal laminectomy.
127
What condition results in prominent lymphocyte casts on urinalysis?
1. Acute interstitial nephritis.
128
What EKG findings are associated with hyperkalemia?
1. Peaked T waves and a prolonged PR interval and QRS duration.
129
What is the treatment of choice for arsenic poisoning?
1. BAL.
130
What inhalational anesthetic is associated with a decreased seizure threshold?
1. Enflurane.
131
What blood product should be used in the treatment of coagulopathy associated with von Willebrand's disease?
1. Cryoprecipitate.
132
What disorder exhibits prominent epithelial cell casts on urinalysis?
1. Acute tubular necrosis.
133
What is the most sensitive method of diagnosing an intraoperative venous air embolus?
1. Transesophageal echo.
134
What position is ideal to minimize complications from a venous air embolism?
1. Left lateral decubitus.
135
What barbiturate lowers seizure threshold?
1. Methohexital.
