1.
A 62-year-old woman is admitted to the emergeny department with abdomnal pains of uncertain origin. A CT scan reveals an aortic aneurysm affecting the origin of the superior mesenteric artery, resulting in ischemia to an abdominal organ. Which of the following organs is most likely affected?
Correct Answer
A. Ileum
Explanation
The superior mesenteric artery supplies blood to the small intestine, including the ileum. Therefore, if there is an aortic aneurysm affecting the origin of the superior mesenteric artery, it is most likely to cause ischemia to the ileum.
2.
A 35-year-old woman comes to a local hospital with abdominal tenderness and acute pain. On examination, her physician observes that an abdominal infection has spread retroperitoneally. Which of the following structures is most likely affected?
Correct Answer
A. Descending colon
Explanation
The correct answer is Descending colon. The question states that the abdominal infection has spread retroperitoneally, which means it is located behind the peritoneum. The descending colon is a retroperitoneal structure, meaning it is located outside of the peritoneal cavity. Therefore, it is most likely affected by the infection.
3.
A 54-year-old man comes to a hospital with abdominal pain, loss of appetite, and weight loss. On examination of his radiograms and computed tomography (CT) scans, a physician finds a slowly growing tumor in the head of the pancreas. Which of the following structures is most likely compressed by this tumor?
Correct Answer
A. Inferior vena cava
Explanation
The tumor in the head of the pancreas is most likely compressing the Inferior vena cava. This is because the Inferior vena cava is located in close proximity to the pancreas, and a tumor in the head of the pancreas can cause compression and obstruction of the Inferior vena cava. This can lead to symptoms such as abdominal pain, loss of appetite, and weight loss, which are consistent with the patient's presentation. Additionally, radiograms and CT scans would help in visualizing the tumor and its effect on nearby structures.
4.
Which of the following muscles is responsible for the anorectal flexure and is important in maintaining fecal continence?
Correct Answer
E. Puborectalis
Explanation
The puborectalis muscle is responsible for the anorectal flexure and is important in maintaining fecal continence. It forms a sling-like structure around the rectum and helps to maintain the angle between the rectum and the anal canal. This muscle plays a crucial role in the control of defecation by contracting to maintain fecal continence and relaxing to allow for the passage of stool.
5.
A medical student auto-inoculates himself with Helicobacter pylori to see what happens. Which of the following is NOT a feature of Helicobacter pylori infection?
Correct Answer
C. Definite association with functional dyspepsia
Explanation
Helicobacter pylori infection is known to have definite associations with gastric ulcer, duodenal ulcer, gastric MALT lymphoma, and gastric cancer. However, it is not definitively associated with functional dyspepsia.
6.
A 47-year-old man has an acquired umbilical hernia, which has split the linea alba and also damaged the posterior lamina of the rectus sheath. A surgeon repairing this defect must remember that at the level of the umbilicus the posterior layer of the rectus sheath consists of which of the following layers?
Correct Answer
C. Transverse abdominal aponeurosis and internal oblique aponeurosis
Explanation
External oblique aponeurosis and internal oblique aponeurosis Form anterior layer of rectus sheath
Transverse abdominal aponeurosis and internal oblique aponeurosis Form posterior layer of rectus sheath.
7.
34 year old woman with several years of “stomach trouble”. She has intermittent abdominal cramping, bloating, and diarrhea sometimes alternating with constipation. There is no associated fevers, weight loss, or rectal bleeding. Family history is positive for diverticulitis in her mother. Her exam is notable for mild tenderness in the lower abdomen but is otherwise unremarkable. Which of the following is the most likely diagnosis?
Correct Answer
E. Irritable bowel syndrome
Explanation
Classic presentation of irritable bowel syndrome.
Celiac disease = slightly higher risk in pts with IBS symptoms but still under 10%
8.
True statements about malabsorption syndromes include:
Correct Answer
A. Loose bowel movements or diarrhea are usually present
Explanation
Malabsorption syndromes refer to conditions where the body is unable to properly absorb nutrients from the gastrointestinal tract. One common symptom of these syndromes is loose bowel movements or diarrhea, which indicates that the body is not absorbing nutrients properly. Therefore, the statement "Loose bowel movements or diarrhea are usually present" is a true statement about malabsorption syndromes.
9.
A 24 year old gentleman presents with several months of abdominal pain and intermittent loose stools. He has lost 15 pounds over this time. He has no fevers or rectal bleeding , and reports no significant travel history.
On exam he is a thin mildly ill-appearing Caucasian male. He has a mild resting tachycardia. He has tenderness and a palpable mass in the right lower quadrant. Labs are notable for microcytic anemia and elevated inflammatory markers. Stool tests are negative for ova & parasites and Giardia.
Which of the following would be most likely?
Correct Answer
D. Crohn’s disease
Explanation
This is a classic clinical presentation for Crohn’s disease. Yersinia or small bowel intussusception would not cause chronic symptoms. Perforated appendicitis would also present more acutely and be associated with fevers.
10.
A 44-year-old accountant develops a bleeding ulcer around tax time. The gastroenterologist visualizes the ulcer in the proximal duodenum. A radiologist has been called to cannulate and embolize the artery supplying the ulcer. Which of the following arteries does the radiologist need to cannulate?
Correct Answer
A. Celiac artery
Explanation
The Celiac artery Supplies the duodenum proximal to the hepatopancreatic ampulla
11.
The surgeon decided that a 35-year-old male patient must undergo an emergency appendectomy due to rupture of his appendix. A midline incision was made for greater access to the peritoneal cavity. The surgeon noted a 5-cm-long fingerlike pouch on the anterior border of the ileum about 60 cm away from the ileocecal junction. Such a pouch is a remnant of which of the following developmental structures?
Correct Answer
C. Vitelline duct
Explanation
Vitelline duct is a Remnant of Stalk of yolk sac
Ligamentum teres is a Remnant of umbilical vein
12.
A 56-year-old male is admitted to the hospital with severe abdominal pain. The patient has a history of "irritiable bowel syndrome" affecting his rectum. Which of the following nerves will most likely be responsible for the transmission of pain in this case?
Correct Answer
A. Pelvic splanchnic nerves
Explanation
The pelvic splanchnic nerves are responsible for transmitting pain signals from the pelvic organs, including the rectum. Irritable bowel syndrome can cause severe abdominal pain, and since the patient's rectum is affected, it is likely that the pelvic splanchnic nerves will be responsible for transmitting the pain in this case. The pudendal nerves are responsible for innervating the perineum and external genitalia, not the rectum. The sacral sympathetic nerves are involved in the sympathetic control of the pelvic organs, but they are not primarily responsible for transmitting pain. The vagus nerves innervate the thoracic and abdominal organs, but they are not specifically involved in transmitting pain from the rectum.
13.
A 16 year old female presents with intermittent bloody diarrhea. Her symptoms began about 8 months ago. She has between 6 and 10 small-volume stools daily, with significant urgency and tenesmus. She has associated cramping and has some nocturnal bowel movements. A flexible sigmoidoscopy is performed, which shows active inflammation beginning at the anal verge and extending continuously to the sigmoid colon. Biopsies are performed, showing acute and chronic inflammatory changes. A diagnosis of ulcerative colitis is made.
Which of the following would be TRUE regarding ulcerative colitis?
Correct Answer
E. None of the above
Explanation
All answers are associated with Crohn’s disease not ulcerative colitis. UC is a mucosal disease not transmural.
14.
A 68 year old male presents with fatigue and shortness of breath. Lab work is notable for severe iron deficiency anemia. The patient undergoes colonoscopy at which time a mass is noted. Surgery is performed the following week.This malignant tumor has arisen in the mucosa of the colon.The most likely precursor lesion for this neoplasm was a(n:
Correct Answer
B. Adenoma
Explanation
The majority of colorectal carcinomas are adenocarcinomas, and the most common pre-cancerous neoplastic precursor of these neoplasms are called adenomas. Squamous dysplasia typically arises in mucosae that are stratified squamous in histology, which the colon is not. A leiomyoma is a benign smooth muscle tumor and not a precursor to adenocarcinoma. Mucosal associated lymphoid tissue does not give rise to epithelial tumors. Enteroendocrine (Kulchitsky) cells are normal constituents of columnar gastrointestinal mucosa that secrete hormones and are not neoplastic precursors.
15.
A 66 year-old woman is evaluated for a 2-day history of progressive fatigue and dark stools. She has not had fever, chills, abdominal pain or bright red rectal bleeding. The patient has a history of osteoarthritis for which she takes ibuprofen 600 mg twice daily.
On physical examination, the temperature is 36.8C, the blood pressure is 136/84 mm Hg, the pulse rate is 92/min, and the respiration rate is 12/min. Cardiac examination shows a regular rhythm with normal heart sounds. The lungs are clear, and there is no peripheral edema. Rectal examination reveals brown stool that is positive for occult blood. Laboratory studies reveal hemoglobin of 8.8 g/dL with a mean corpuscular volume of 80; serum biochemistry tests, including liver chemistry tests, and prothrombin time, activated partial thromboplastin time, and INR are normal. EGD and colonoscopy are normal. Small-bowel capsule endoscopy shows several ulcers in the mid-small bowel.
Which of the following is the most appropriate next step in the management of this patient?
Correct Answer
A. Discontinue ibuprofen therapy
Explanation
The patient presents with obscure GI bleeding and has NSAID-induced small bowel ulcers. NSAID therapy can cause ulceration in the small bowel and colon. She is not having active bleeding that would warrant angiography or surgery, and does not have evidence of portal hypertension.
16.
Mr. Jones is 24 year old man presents to for a second opinion regarding Crohn’s disease. He was initially treated with steroids with good response. His gastroenterologist subsequently started azathioprine but he was intolerant of this medication. He was then started on infliximab (an anti-TNF therapy) with a good initial response but in recent months the patient’s symptoms are no longer responsive to this drug.
Mr. Jones asks you what medications might be under development or in clinical trials that could decrease his intestinal inflammation. Based on your knowledge of the mucosal immune system which of the following potential drug(s) could be developed as a treatment to suppress intestinal inflammation associated with Crohn’s disease?
Correct Answer
F. B and E
Explanation
Crohn's disease is associated with abnormal Th1-associated inflammation. Giving IL12 would likely increase Th1 response and blocking IL10 would also increase Th1 predominance.