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Free STEP1 Exam Braindumps (page: 36)

Page 35 of 213
PDF with 845 Questions

A 42-year-old female patient has to undergo emergency cholecystectomy due to intense biliary colic. The structure to be removed during the surgery is indicated in following figure by which of the following arrows?

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5

Answer(s): B

Explanation:

Arrow 2 points to the gallbladder, which will be removed during the cholecystectomy (surgical removal of the gallbladder). Biliary colic may be due to impaction of a gallstone in the cystic duct, resulting in cholecystitis (inflammation of the gallbladder). Arrow 1 (choice A) points to the liver. Arrow 3 (choice C) points to the transverse colon. Arrow 4 (choice D) points to the spleen and arrow 5 (choice E) indicates the stomach, recognizable by its internal rugae.



Apatient with a developing astroglioma in the primary auditory cortex (Brodmann's area 41) complains of hearing unusual noises. What is the main source of subcortical input to the primary auditory cortex?

  1. inferior colliculus
  2. lateral geniculate nucleus
  3. medial geniculate nucleus
  4. superior colliculus
  5. superior olivary nucleus

Answer(s): C

Explanation:

The main subcortical afferents to the primary auditory cortex (Brodmann's area 41) arise from the medial geniculate nucleus of the thalamus. The inferior colliculus (choice A) is a midbrain auditory relay nucleus, which sends projections to the medial geniculate nucleus. The lateral geniculate nucleus (choice B) is a visual relay nucleus in the thalamus and it projects to the primary visual cortex (Brodmann's area 17). The superior colliculus (choice D) is a midbrain visual relay nucleus, which provides fibers to the tectospinal tract. The superior olivary nucleus (choice E) is a medullary auditory relay nucleus, which sends projections to the cochlea.



A 65-year-old male patient develops neurological symptoms due to an embolus in the left common carotid artery. In the CT scan in following figure, the involved vessel is indicated by which of the following arrows?

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5

Answer(s): D

Explanation:

Arrow 4 points to the left common carotid artery. The three arteries arising from the arch of the aorta are lined anteriorly to posteriorly on a slanted line: arrow 3 (choice C) shows the brachiocephalic artery, arrow 4 (choice D) points to the left common carotid artery, and arrow 5 (choice E) indicates the left subclavian artery. Arrow 2 (choice B) points to the right brachiocephalic vein, which is joined here by the left brachiocephalic vein. Arrow 1 (choice A) points to the trachea, which is filled with air and thus is not radiopaque.



A 53-year-old male patient has developed an abnormal hypersensitivity in the face area. He complains that he feels pain when he drives with the window down and from the wind blowing on his face. The pain is exacerbated by direct touch to the left side of his lower jaw. The patient is diagnosed with trigeminal neuralgia (tic douloureux). Where do pain fibers from the left side of his mandible project to?

  1. mesencephalic trigeminal nucleus
  2. motor trigeminal nucleus
  3. principal sensory trigeminal nucleus
  4. spinal (descending) trigeminal nucleus
  5. trigeminal (gasserian) ganglion

Answer(s): D

Explanation:

Fibers from pain and temperature receptors in the face area all project to the spinal (descending) trigeminal nucleus. The mesencephalic trigeminal nucleus (choice A) contains the perikarya of the proprioceptive fibers of the muscles of mastication. The motor trigeminal nucleus (choice B) receives innervations from the mesencephalic trigeminal nucleus. The principal sensory trigeminal nucleus (choice C) receives somatosensory fibers from the face, gums, teeth, and anterior two-thirds of the tongue. The trigeminal (gasserian) ganglion (choice E) contains the sensory perikarya of all three subdivisions of the trigeminal nerve.






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