Exam 2 Review
Jeff Weiner
Development of the GI System I and II- Dr. Lane
1. The esophagus, stomach, proximal half of the duodenum, liver and pancreas arise from the:
A. Foregut
B. Midgut
C. Hindgut
D. Proctodeum
2. Which of the following statements is NOT correct?
A. The gut is lined by endoderm, which forms the epithelium and glands of the adult digestive tract.
B. Paraxial mesoderm surrounding the primordial gut forms the muscle and connective tissue layers
of the digestive tract.
C. The cranial end of the primitive gut is lined by ectoderm and known as the stomodeum.
D. The caudal end of the primitive gut is lined by ectoderm and known as proctodeum.
3. By the end of the 3rd month:
A. Only the primordial gut has formed.
B. Parietal cells have differentiated.
C. The digestive system is fully functional.
D. The adult organization of the gut is present.
4. Which of the following statements regarding the mesentery are correct?
A. The primordial gut is suspended in the peritoneal cavity by the ventral mesentery.
B. The dorsal mesentery persists in the adult as the falciform ligament, the lesser omentum, and the
visceral peritoneum of the liver.
C. With the exception of several structures, most of the ventral mesentery degenerates.
D. The kidneys are examples of organs that are secondarily retroperitoneal.
5. What can result from a failure of the neural crest cells to migrate to the gut?
A. Ret gene overproduction, upregulating Na/K pump expression on gut cells
B. Aganglionic megacolon (Hirschsprung’s Disease)
C. Cystic fibrosis
D. Congenital polyps
6. Esophageal stenosis and duplication are results of errors in what process?
1. Recapitulation
2. Defenestration
3. Breast augmentation
4. Recanalization
7. What are typical characteristics of an individual with esophageal stenosis?
A. The esophageal lumen is significantly narrowed.
B. Excess amniotic fluid.
C. The esophagus will have a blind end, or is incomplete.
D. The patient will suffer from GERD.
8. Which of the following statements regarding stomach development are NOT correct?
A. Development begins during the fourth week as a dorsal enlargement of the caudal foregut.
B. As the stomach enlarges it rotates 90 degrees counterclockwise, with the greater curvature ending
up on the right side of the stomach.
C. Differential growth leads to the formation of the greater and lesser curvatures of the stomach.
D. As the stomach rotates it pulls the dorsal mesogastrium (precursor to the greater omentum) to the
left, forming a cavity behind the stomach known as the lesser sac.
Exam 2 Review
Jeff Weiner
9. Which of the following are NOT developmental errors that can be associated with the duodenum?
A. Atresia
B. Stenosis
C. Polyhydraminos
D. Agenesis
10. Which of the following statements regarding liver and biliary apparatus development are NOT correct?
A. These structures arise from evagination of the ventral surface of the caudal foregut known as the
biliary diverticulum.
B. The reflections of ventral mesentery onto the diaphragm become the coronary and triangular
ligaments that surround the bare area of the liver.
C. Endoderm cells proliferate and form cords of hepatic cells and epithelia of the biliary system
within the liver.
D. The gall bladder and cystic duct forms from the small caudal part of the hepatic diverticulum.
11. The pancreas:
A. Arises from two evaginations of the caudal foregut called the pancreatic buds.
B. The neck, body, and tail are derived from the larger dorsal pancreatic bud.
C. The ventral bud forms the uncinate process and part of the head of the pancreas.
D. The duct of the ventral bud and distal part of the dorsal bud form the main pancreatic duct.
E. All of the above.
12. What pancreatic developmental abnormality can result in duodenal obstruction?
A. Accessory pancreatic tissue
B. Anular pancreas
C. Congenital pancreatitis
D. Diabetes mellitus
13. All derivatives of the midgut:
A. Include the descending colon and rectum.
B. Are supplied by the inferior mesenteric artery.
C. Are supplied by the superior mesenteric artery.
D. Have haustra and teniae coli in their adult structures.
14. Which of the following statements regarding midgut rotation are NOT correct?
A. During week 6, midgut elongation exceeds the capacity of the peritoneal cavity, producing a
physiological herniation of the midgut into the extraembryonic coelom.
B. While out in the yolk sac the foregut rotates 90 degrees counterclockwise.
C. The small intestine returns to the abdomen in week ten and occupies the central part.
D. The large intestines return, rotating another 180 degrees counterclockwise, placing the cecum and
ascending colon on the right side of the abdomen and the transverse colon just inferior to the liver.
15. What is the clinical relevance of fixation of the intestine?
A. Helps immobilize parts of the GI tract, and creates gutters for flow of fluid.
B. Without fixation, peristalsis cannot occur.
C. Fixation is not relevant.
D. If there is no fixation of the intestine, then it follows that mesenteries do not fuse to the posterior
abdominal wall. If mesenteries do not fuse to the posterior abdominal wall, then what has this all
been about? What has this all been about?!
16. Have you studied the malrotation of the midgut on page 67? Can you match the picture to a
description?
A. Yes
B. No
C. This was not a helpful practice question
Exam 2 Review
Jeff Weiner
17. You assist in the delivery of an infant, born 3 weeks premature. The infant presents with a hernia of
abdominal viscera through the lateral wall of the abdomen. It appears that no extra layers (epithelium,
peritoneum, mesentery, etc) cover the viscera. Based on your knowledge, what does this newborn infant
appear to be suffering from?
A. Omphalocele, caused by the failure of intestine to return to the abdominal cavity in week 10.
B. Umbilical hernia
C. Gastroschisis caused by a defective closure of the lateral folds during week 4 of development.
D. Internal hernia caused by a loop of small intestine going through the mesentery of adjacent
sigmoid colon.
E. None of the above.
18. 2-4% of the population have Ileal (Meckel) Diverticulum, caused by a persistent yolk sac that may be
attached to the umbilicus. For many this is an asymptomatic condition, for others there may be
complications. Which of the following complications are NOT associated with ileal diverticulum?
A. Vitelline cysts
B. Fibrous cords
C. Omphaloenteric fistula
D. Volvulus of diverticulum.
E. Priapism
19. Which of the following statements regarding the development of the hindgut are NOT correct?
A. Branches of the celiac trunk supply all derivatives of the hindgut.
B. The cloaca receives the allantois, an extension of the yolk sac that is continuous with the region of
the urogenital wall that will become the urinary bladder, and whose remnant is the urachus.
C. During development the cloaca is subdivided by the urorectal septum into a ventral urogenital
region and a dorsal anal-rectal region.
D. At week 7 the urorectal septum fuses with the cloacal membrane at the future perineal body.
20. The anal canal:
A. The upper 2/3 is derived from the hindgut.
B. The lower 1/3 is derived from the proctodeum.
C. The pectinate line represents the border between the two and also is the site of the former anal
membrane.
D. Hemorrhoids found deep to the pectinate line are known as internal hemorrhoids.
E. All of the above.
21. I also don’t know how to phrase this as a question, but be visually familiar with the anorectal anomalies
on page 73.