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Free STEP1 Exam Braindumps (page: 23)

Page 22 of 213
PDF with 845 Questions

Horner syndrome is sometimes seen in patients diagnosed with the lateral medullary syndrome. Which of the following is a characteristic feature of Horner syndrome?

  1. atrophy of tongue musculature
  2. mydriasis
  3. paralysis of muscles of facial expression
  4. profuse sweating
  5. red blushing of the skin in the affected area

Answer(s): E

Explanation:

The skin in the affected area is red and dry (not moist as in choice D) due to diminished sympathetic activity. The pupil on the affected side is constricted (myosis) (not dilated as in choice B) due to unopposed activity of the sphincter pupillae muscle. Motor deficits such as atrophy of tongue musculature (choice A) or paralysis of facial expression muscles (choice C) are typically not part of Horner syndrome.



A 52-year-old male patient with a history of alcoholism is brought to the emergency room because of a sudden onset of right upper quadrant pain, nausea, blood in the vomitus, and fever. Ultrasound diagnosis reveals a portal vein obstruction caused by liver cirrhosis and accompanied by esophageal varices. Proper portal circulation must be reestablished to alleviate the esophargeal varices, and the attending surgeon decides on an end-to-side portocaval shunt. Which of the following describes the chosen procedure?

  1. anastomosis by communication between the portal vein and the inferior vena cava
  2. anastomosis by prosthetic vascular graft between the inferior vena cava and the superior mesenteric vein
  3. anastomosis by suturing the inferior end of the portal vein to the inferior vena cava
  4. anastomosis of the splenic vein to the left renal vein
  5. placement of an expandable stent between a hepatic vein and the portal vein

Answer(s): C

Explanation:

Suturing the inferior end of the portal vein to the inferior vena cava is termed end-to-side portocaval shunt, whereas establishing a communication between the portal vein and the inferior vena cava (choice A) is a side-to-side portocaval shunt. Placing a prosthetic vascular graft between the inferior vena cava and the superior mesenteric vein (choice B) is termed a mesocaval shunt. Anastomosis of the splenic vein to the left renal vein (choice D) is a splenorenal or Warren shunt. Placement of an expandable stent between the hepatic vein and portal vein (choice E) is called a transjugular intrahepatic portosystemic shunt or TIPS.



During surgical resection of the gastrointestinal tract for treatment of long-standing irritable bowel syndrome, a surgery resident is asked to select a surgical site coinciding with the termination of the vagal innervation. Which of the following does she select?

  1. duodenojejunal junction
  2. ileocolic junction
  3. junction of the second part and third part of the duodenum
  4. left colic (splenic) flexure
  5. right colic (hepatic) flexure

Answer(s): D

Explanation:

The left colic (splenic) flexure represents the junction of the midgut to the hindgut during embryonic development. The vagus (tenth cranial) nerve provides the parasympathetic innervation of the digestive tract up to this flexure, whereas the pelvic parasympathetic fibers from S2-S4 innervate the rest of the tract.
The duodenaljejunal junction (choice A), ileocolic junction (choice B), and rightcolic (hepatic) flexure (choice E) are anatomical landmarks along the digestive tract without change in parasympathetic innervation. The junction of the second part and third part of the duodenum (choice C) represents the embryonic junction between the foregut and the midgut, but both receive vagal innervation.



The structure indicated by arrow 1 in following figure is innervated by which of the following?

  1. anterior ethmoidal nerve
  2. greater palatine nerve
  3. lesser palatine nerve
  4. middle superior alveolar nerve
  5. nasopalatine nerve

Answer(s): D

Explanation:

Arrow 1 points to the maxillary sinus, which is innervated by the posterior, middle, and anterior superior alveolar nerves. The latter are branches from the infraorbital nerve arising from the maxillary division (V2) of the trigeminal (fifth cranial) nerve. The anterior ethmoidal nerve (choice A) is a branch of the nasociliary nerve from the ophthalmic division (V1) of the trigeminal nerve. The greater palatine nerve (choice B) and lesser palatine nerve (choice C) are branches of the maxillary division of the trigeminal nerve supplying the hard and soft palate, respectively. The nasopalatine nerve (choice E) is derived from the maxillary division of the trigeminal nerve and supplies the nasal septum.






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