NBME 13 (Explanations) Actual Questions With All Correct Answers

NBME 13 (Explanations) Actual Questions With All Correct Answers hx of urinary frequency and urgency, 3mo hx of walking difficulty, problems with conversation and memory; normal strength and sensation; mini cog average-normal; wide shuffling gait; ct shows enlarged ventricles - CORRECT ANSWER normal pressure hydrocephalus --*wet, wobbly, wacky* triad of urinary incontinence, ataxia, cognitive dysfunction --expands ventricles that distort fibers of the corona radiata that lead to dementia, ataxia, urinary incontinence --does not increase subarachnoid space volume --common in elderly and idiopathic IHC positive for chromogranin indicates cancer of what origin? - CORRECT ANSWER neuroendocrine or carcinoid 10% of pheochromocytomas are extraadrenal, occurring in sites such as the organ of Zuckerkandl and the carotid body, where they usually are called __ - CORRECT ANSWER paragangliomas, rather than pheochromocytomas Pheochromocytomas usually subscribe to a convenient rule of 10s - CORRECT ANSWER --10% of pheochromocytomas are extraadrenal, occurring progressive weakness, dec strength, hand muscle atrophy, diffuse hyperreflexia and fascicultations on hands and arms, normal sensory exam; - CORRECT ANSWER amyotrophic lateral sclerosis (ALS) --death of both upper and lower motor neurons in the motor cortex of the brain, the brain stem, and the spinal cord --Stephen Hawking disease --*UMN and LMN signs* --rapidly progressive weakness with fasciculations eventually leading to muscle atrophy, spasticity, dysarthria, dysphagia, respiratory compromise, death from respiratory failure UMN vs LMN weakness - CORRECT ANSWER --UMN weakness (brain to spinal cord) manifests in hyperreflexia and rigid muscle tone, positive Babinski sign --LMN weakness (anterior horn to muscle) manifests in muscle atrophy, decreased reflexes, fasciculations, and flaccid muscle tone history of numbness of fingers on left hand, loss of touch graphesthesia, loss of two point discrimination in left hand - CORRECT ANSWER --lesion in somatosensory cortex on contralateral side (right hemisphere) --graphesthesia is the ability to sense what is being drawn or written via touch on their hand --the postcentral gyrus is a prominent structure in the parietal lobe of the human brain; it is the location of the primary somatosensory cortex, the main sensory receptive area for the sense of touch missense mutation of tyrosine kinase domain of TrkA gene disrupts what process? - CORRECT ANSWER phosphorylation of downstream molecules in response to nerve growth factor --A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to a protein in a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases are a subclass of protein kinase. --The presence of this kinase leads to cell differentiation and may play a role in specifying sensory neuron subtypes. Mutations in this gene have been associated with congenital insensitivity to pain with anhidrosis, self-mutilating behavior, mental retardation and cancer this part of the brain is affected most in chronic alcoholics - CORRECT ANSWER --anterior vermis --a lesion in the vermis causes truncal ataxia, gait ataxia, and dysarthria suppression vs. repression - CORRECT ANSWER suppression: mature defense suppression is the voluntary withholding of an idea of feeling from conscious awareness, like not thinking about an exam until the week of it or doctor controlling anger at alcoholic pts he doesnt like repression: immature defense repression is someone involuntarily withholding something from consciousness like not remembering going to counseling for parents divorce reaction formation - CORRECT ANSWER replace a bad/warded off feeling/idea with an emphasis on its opposite; someone with libidinous thoughts enters a monastery sublimation - CORRECT ANSWER mature reaction formation; replacing unacceptable wish with action similar to wish but does not conflict with their values, like teens aggression toward father redirected to perform well in sports elderly woman with 1moin sites such as the organ of Zuckerkandl and the carotid body, where they usually are called paragangliomas, rather than pheochromocytomas. --10% of adrenal pheochromocytomas are bilateral; this proportion may rise to 50% in cases that are associated with familial syndromes.