GI development Practice Questions

Question 1

A 7-month-old boy is brought to the ED by his mother because of abdominal pain. Two weeks ago, she noticed he had a fever and looser stools, but both resolved after a few days. One week ago, he began to experience periodic episodes during which he would curl up into a ball, scream, and cry. The episodes lasted a few minutes, and were occasionally followed by vomiting. Between events, he was completely normal. She says the episodes have become more frequent over time, and this morning, she noticed blood in his diaper. In the ED, his vitals are within normal ranges, and his physical exam is normal. After confirming the diagnosis with an abdominal ultrasound, what is the next step in management?

Accepted Answer

Air contrast enema

Answer

Supportive care

Answer

Broad-spectrum antibiotics

Answer

Abdominal laparotomy

Answer

Abdominal CT scan

Question 2

A 13-year-old girl presents to an orthopedic surgeon for evaluation of a spinal curvature that was discovered during a school screening. She has otherwise been healthy and does not take any medications. On presentation, she is found to have significant asymmetry of her back and is sent for a spine radiograph. The radiograph reveals a unilateral rib attached to the left transverse process of the C7 vertebrae. Abnormal expression of which of the following genes is most likely responsible for this finding?

Accepted Answer

Homeobox

Answer

WNT7

Answer

FGF

Answer

PAX

Answer

Sonic hedgehog

Question 3

A research team is studying certain congenital anomalies of the respiratory tract. The method consists of marking a certain germinal layer with an isotope, following its development stages in chicken embryos, and finally analyzing the specimen. A given specimen of tissue is presented in the exhibit. Which of the following germinal structures most likely gave rise to the epithelial lining of this specimen?

Accepted Answer

Endoderm

Answer

Ectoderm

Answer

Neural crest

Answer

Mesoderm

Answer

Surface ectoderm

Question 4

A 10-month-old infant is brought in by his parents because he is vomiting and not passing stool. His parents say he has vomited multiple times over the past couple of hours, but the most recent vomit was green. The patient has no significant past medical history. On physical examination, the patient is irritable and crying. On palpation in the periumbilical region, an abdominal mass is present. Emergency laparotomy is performed, which shows a part of the patient’s intestine folded into the section adjacent to it. Which of the following is the most likely diagnosis for this patient?

Accepted Answer

Intussusception

Answer

Pyloric stenosis

Answer

Hirschsprung’s disease

Answer

Duodenal atresia

Answer

Meckel’s diverticulum

Question 5

A 4-month-old girl is brought to the physician because she has been regurgitating and vomiting 10–15 minutes after feeding for the past 3 weeks. She is breastfed and formula-fed. She was born at 38 weeks' gestation and weighed 2966 g (6 lb 9 oz). She currently weighs 5878 g (12 lb 15 oz). She appears healthy. Vital signs are within normal limits. Examination shows a soft and nontender abdomen and no organomegaly. Which of the following is the most appropriate next best step in management?

Accepted Answer

Positioning therapy

Answer

Upper endoscopy

Answer

Ultrasound of the abdomen

Answer

Esophageal pH monitoring

Answer

Pantoprazole therapy

Question 6

A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

Accepted Answer

"Can you tell me more about the symptoms you have been experiencing?"

Answer

"Does the diarrhea typically precede the constipation, or vice-versa?"

Answer

"Is the diarrhea foul-smelling?"

Answer

"Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"

Answer

"Are the symptoms worse in the morning or at night?"

Question 7

A 23-year-old man comes to the physician for evaluation of decreased hearing, dizziness, and ringing in his right ear for the past 6 months. Physical examination shows multiple soft, yellow plaques and papules on his arms, chest, and back. There is sensorineural hearing loss and weakness of facial muscles bilaterally. His gait is unsteady. An MRI of the brain shows a 3-cm mass near the right internal auditory meatus and a 2-cm mass at the left cerebellopontine angle. The abnormal cells in these masses are most likely derived from which of the following embryological structures?

Accepted Answer

Neural crest

Answer

Surface ectoderm

Answer

Neural tube

Answer

Notochord

Answer

Mesoderm

Question 8

An 11-year-old girl is brought to the office by her mother due to complaint of intermittent and severe periumbilical pain for 1 day. She does not have any significant past medical history. She provides a history of a recent school trip to the suburbs. On physical examination, there is a mild tenderness around the umbilicus without any distension or discharge. There is no rebound tenderness. Bowel sounds are normal. An abdominal imaging shows enlarged mesenteric lymph nodes, and she is diagnosed with mesenteric lymphadenitis. However, incidentally, a mass of tissue was seen joining the inferior pole of both kidneys as shown in the image. Which of the following best describes this renal anomaly?

Accepted Answer

Association with ureteropelvic junction obstruction (UPJO)

Answer

Fused kidneys ascend beyond superior mesenteric artery.

Answer

Rapid progression to acute renal failure

Answer

Kidneys are usually non-functional.

Answer

Increased risk of developing renal vein thrombosis

Question 9

An investigator is studying the effects of an antihypertensive drug during pregnancy. Follow-up studies show that the drug can adversely affect differentiation of the ureteric bud into its direct derivatives in fetuses exposed during the first trimester. Which of the following structures is most likely to develop incorrectly in the affected fetus?

Accepted Answer

Collecting ducts

Answer

Proximal convoluted tubule

Answer

Loop of Henle

Answer

Bladder

Answer

Distal convoluted tubule

Question 10

A 45-year-old woman comes to the physician because of progressive difficulty swallowing solids and liquids over the past 4 months. She has lost 4 kg (9 lb) during this period. There is no history of serious illness. She emigrated to the US from Panama 7 years ago. She does not smoke cigarettes or drink alcohol. Cardiopulmonary examination shows a systolic murmur and an S3 gallop. A barium radiograph of the chest is shown. Histopathologic examination of the esophageal wall is most likely to show which of the following?

Accepted Answer

Absence of myenteric plexus neurons

Answer

Presence of intranuclear basophilic inclusions

Answer

Atrophy of esophageal smooth muscle cells

Answer

Infiltration of eosinophils in the epithelium

Answer

Presence of metaplastic columnar epithelium

GI development

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Primitive gut formation

Foregut development and derivatives

Midgut development and rotation

Hindgut development

Liver and biliary system development

Pancreas development

Spleen development

Abdominal wall development

Diaphragm development

Congenital anomalies of GI tract

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About GI development for USMLE

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