Lippincott Gastrointestinal Tract - Chapter 13
During your examination of the specimen described in Question 37, you are asked to discuss microfold (M) cells and mucosa-associated lymphoid tissue. What is the principal function of M cells in the distal ileum? (A) Antigen uptake (B) Fluid transport (C) Gastrin secretion (D) Histamine release (E) Chemoreception
(A) Antigen uptake
The visible mucus identified in Question 10 contains a high concentration of which of the following biomolecules? (A) Bicarbonate and potassium (B) Hydrochloric acid (C) Lysozyme (D) Polypeptide hormones (E) Proteases
(A) Bicarbonate and potassium
For the autopsy specimen provided for Question 17, identify the basophilic cells clustered at the base of the gastric glands (lower right corner, shown in the image). (A) Chief cells (B) Enteroendocrine cells (C) Mucous cells (D) Paneth cells (E) Parietal cells
(A) Chief cells
You are analyzing patterns of stem cell renewal and terminal differentiation in the GI tract. As part of your research, you generate monoclonal antibodies that identify specific populations of gastric epithelial cells. One of your antibodies recognizes a protease found in zymogen granules. Which of the following cells is characterized by the presence of zymogen secretory granules? (A) Chief cells (B) Enteroendocrine cells (C) Mucous cells (D) Parietal cells (E) Plasma cells
(A) Chief cells
After your lecture, a colleague asks you to comment on recent drug discovery efforts to regulate nutrient uptake in the small intestine. What hormone stimulates gallbladder contraction and pancreatic enzyme secretion? (A) Cholecystokinin (B) Gastrin (C) Ghrelin (D) Leptin (E) Secretin
(A) Cholecystokinin
During the seminar, you are asked to discuss the cellular mechanisms that mediate antibody transport across the epithelial barrier of the GI tract. Which of the following cells transports IgA from the lamina propria of the mucosa to the lumen of the gut? (A) Enterocytes (B) Goblet cells (C) Microfold cells (D) Paneth cells (E) Plasma cells
(A) Enterocytes
The gastrointestinal (GI) tract is compartmentalized into organs that are specialized for digestion of food and absorption of nutrients. Most variation and specialization along the length of the GI tract occur in which of the following tissue layers? (A) Epithelium of mucosa (B) Lamina propria (C) Muscularis externa (D) Muscularis mucosae (E) Submucosa
(A) Epithelium of mucosa
A 2-year-old girl with a history of chronic constipation since birth is brought to the emergency room because of nausea and vomiting. Physical examination shows marked abdominal distension. Abdominal radiography reveals distended bowel loops. Which of the following developmental defects explains the pathogenesis of congenital megacolon in this patient? (A) Failure of neural crest migration (B) Hypertrophy of smooth muscle (C) Incomplete canalization of the primitive gut tube (D) Malrotation of the primitive gut tube (E) Persistence of the vitelline duct
(A) Failure of neural crest migration
During a small group seminar, you are asked to discuss humeral immunity in the GI tract. Plasma cells in the lamina propria secrete primarily which of the following classes of immunoglobulin? (A) IgA (B) IgD (C) IgE (D) IgG (E) IgM
(A) IgA
A 2-year-old boy is brought to the emergency room with a 48-hour history of nausea and abdominal discomfort. Physical examination reveals right lower quadrant guarding. Ultrasound examination of the abdomen reveals a 2-cm mass near the ileocecal junction. The child is discovered to have an obstruction caused by abnormal intestinal peristalsis. What is the appropriate pathologic diagnosis? (A) Intussusception (B) Meconium ileus (C) Stricture (D) Torsion (E) Volvulus
(A) Intussusception
A 45-year-old man describes burning epigastric pain 2 to 3 hours after eating. Foods, antacids, and over-the-counter medications provide no relief, and prescribed inhibitors of acid secretion are only moderately effective. Endoscopy reveals multiple gastric and duodenal peptic ulcers. An abdominal CT scan reveals a pancreatic tumor. What polypeptide hormone is most likely secreted by this pancreatic islet cell neoplasm? (A) Cholecystokinin (B) Gastrin (C) Ghrelin (D) Motilin (E) Secretin
(B) Gastrin
A 3-week-old boy is brought to the physician by his parents who report that he vomits forcefully immediately after nursing. Imaging studies reveal concentric enlargement of the pyloric canal. Which of the following best explains the pathogenesis of congenital pyloric stenosis in this infant? (A) Deviation of the septum transversum (B) Hypertrophy of smooth muscle (C) Incomplete canalization of the primitive gut tube (D) Malrotation of the primitive gut tube (E) Persistence of the vitelline duct
(B) Hypertrophy of smooth muscle
Examination of the lamina propria of the organ identified in Question 3 reveals which of the following key histologic features of the GI tract? (A) Brunner glands (B) Lacteals (C) Meissner plexuses (D) Myenteric plexuses (E) Pyloric glands
(B) Lacteals
You are invited to give a lecture on the pathobiology of enteroendocrine cells at a national conference on "childhood obesity" organized by First Lady Michelle Obama. During your lecture, you mention that enteroendocrine cells secrete a wide variety of polypeptide hormones. Which hormone produced in the stomach stimulates the perception of hunger? (A) Cholecystokinin (B) Gastrin (C) Ghrelin (D) Leptin (E) Secretin
(C) Ghrelin
Another of your monoclonal antibodies identifies proliferating stem cells in the gastric mucosa. You hope to use this antibody to isolate these progenitor cells using fluorescence-activated cell sorting (FACS). Which of the following locations in the mucosa provides a niche for multipotent gastric stem cells? (A) Fundus of glandular epithelium (B) Gastric pit (C) Isthmus of glandular epithelium (D) Lamina propria (E) Neck of glandular epithelium
(C) Isthmus of glandular epithelium
You are investigating the activation of smooth muscle in the muscularis mucosae of the stomach and its role in assisting outflow from gastric glands. The cell bodies for visceral motor fibers that innervate the muscularis mucosae are present in which of the following anatomic locations? (A) Auerbach plexus (B) Celiac ganglion (C) Meissner plexus (D) Nucleus ambiguous of the CNS (E) Sympathetic trunk
(C) Meissner plexus
A 44-year-old woman presents with burning epigastric pain that usually occurs between meals. The pain can be relieved with antacids. The patient also reports a recent history of tarry stools. Gastroscopy reveals a bleeding mucosal defect in the antrum measuring 1.5 cm in diameter. Which of the following is the most likely underlying cause of peptic ulcer disease in this patient? (A) Alcohol abuse (B) Aspirin use (C) Emotional stress (D) Infection (E) Tumor
(D) Infection
A 74-year-old woman complains of weakness and fatigue. She states that her stools have recently become black after taking a new nonsteroidal anti-inflammatory drug (NSAID). Gastroscopy reveals superficial, bleeding mucosal defects. What is the most likely mechanism for the development of acute erosive gastritis in this patient? (A) Activation of Hageman factor (B) Activation of serum kallikrein (C) Generation of membrane attack complex (D) Inhibition of cyclooxygenase (E) Mast cell degranulation
(D) Inhibition of cyclooxygenase
A 45-year-old man complains of difficulty swallowing and a tendency to regurgitate his food. Further studies demonstrate a complete absence of peristalsis and failure of the lower esophageal sphincter to relax upon swallowing. These clinicopathologic findings are explained as a deficiency (or absence) of which of the following structures in the distal esophagus? (A) Ganglion cells in the Auerbach plexus (B) Ganglion cells in the Meissner plexus (C) Presynaptic parasympathetic nerves (D) Presynaptic sympathetic nerves (E) Smooth muscle in the muscularis externa
(D) Presynaptic sympathetic nerves
During a clinical conference, you are asked to discuss physiological mechanisms that protect the stomach from the acidity of gastric juice and from mechanical abrasion. Which of the following small molecules plays an important role in maintaining bicarbonate secretion by surface mucous cells and increasing the thickness of the surface mucus layer in the stomach? (A) Histamine (B) Kinins (C) Nitric oxide (D) Prostaglandins (E) Serotonin
(D) Prostaglandins
What cell surface glycoprotein found on M cells suggests that these phagocytic cells present antigens to lymphocytes in the GI tract? (A) CD4 (B) CD8 (C) IgM (D) MHC class I (E) MHC class II
(E) MHC class II
Microscopic examination of the distal portion of the autopsy specimen provided for Question 5 reveals intestine-like glandular epithelium with goblet cells. These histopathologic findings are associated with which of following adaptations to chronic persistent cell injury? (A) Atrophy (B) Dysplasia (C) Hyperplasia (D) Hypertrophy (E) Metaplasia
(E) Metaplasia
A 34-year-old man presents with a 5-month history of weakness and fatigue. A peripheral blood smear shows megaloblastic anemia. Further laboratory studies demonstrate vitamin B12 deficiency. This patient's anemia is most likely caused by autoantibodies directed against which of the following GI cells? (A) Chief cells (B) Enteroendocrine cells (C) Microfold cells (D) Paneth cells (E) Parietal cells
(E) Parietal cells
A 58-year-old woman with a history of indigestion after meals and "heartburn" presents with upper abdominal pain. She is currently being treated with proton pump inhibitors for gastroesophageal reflux disease (GERD). Which of the following types of epithelial cells has proton pumps and generates hydrochloric acid (HCl) within the lumen of the stomach? (A) Chief cells (B) Enterocytes (C) Goblet cells (D) Paneth cells (E) Parietal cells
(E) Parietal cells
During a small group discussion, you are asked to explain structural and functional differences between rugae, villi, microvilli, plicae circulares, teniae coli, and haustra. Rugae are found in which of the following segments of the GI tract? (A) Esophagus (B) Large intestine (C) Rectum/anal canal (D) Small intestine (E) Stomach
(E) Stomach
