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Repeated USMLE Questions Step 1- Review- 33

Q- Which one of the following structures provides the majority of noradrenergic innervation to the cerebral cortex?

A- Caudate nucleus

B- Locus coeruleus

C- Raphe nucleus

D- Substantia nigra

B- Locus coeruleus- These cells contain norepinephrine and they provide the majority of noradrenergic innervation to the forebrain.



Q- Which of the following physiological changes is expected in a person comping on a mountain at an altitude of 4500 meters?

A- Decreased 2,3-diphosphoglycerate

B- Decreased erythropoietin production

C- Decreased arterial Pco2

D- Increased renal excretion of H ion

C- Decreased arterial Pco2- Decreased barometric pressure in high altitude causes arterial hypoxia. Ventilation rate increases leading to decreased arterial Pco2 and respiratory alkalosis.



Q- A woman, tested genetically for glucose-6-phasphate dehydrogenase deficiency, is found to have only one defective X chromosome. She is married to a man with normal X chromosome. She is pregnant with a female fetus.

Which of the following is most likely expected in her baby girl?

A-The baby has 100% chance to clinically have the disease

B-The baby has 50% chance to clinically have the disease

C- The baby has no chance to be a carrier

D- The baby has 50% chance to be a carrier

D- The baby has 50% chance to be a carrier- The father has 1 normal X chromosome. The mother has one normal and one abnormal so, the rate to be X normal and X abnormal is 50%.



More Repeated USMLE Questions Step 1

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