Abdomen Flashcards
- A 63-year-old man comes to the emergency department with back pain, weakness, and short- ness of breath. On examination, he has an aneurysm of the abdominal aorta at the aortic hiatus of the diaphragm. Which of the following pairs of structures would most likely be compressed?
(A) Vagus nerve and azygos vein
(B) Esophagus and vagus nerve
(C) Azygos vein and thoracic duct
(D) Thoracic duct and vagus nerve
(E) Inferior vena cava (IVC) and phrenic nerve
C. The aortic hiatus of the diaphragm transmits the azygos vein and thoracic duct. The vagus nerve passes through the esophageal hiatus, and the right phrenic nerve may run through the vena caval hiatus.
- A 36-year-old woman with yellow pigmentation of the skin and sclerae presents at the outpatient clinic. Which of the following conditions most likely is the cause of her obstructive jaundice?
(A) Aneurysm of the splenic artery
(B) Perforated ulcer of the stomach
(C) Obstruction of the main pancreatic duct
(D) Cancer in the head of the pancreas
(E) Cancer in the body of the pancreas
D. Because the bile duct traverses the head of the pancreas, cancer in the head of the pancreas obstructs the bile duct, resulting in jaundice. Aneurysm of the splenic artery, obstruction of the main pancreatic duct, a stomach ulcer, and cancer in the body of the pancreas are not closely associated with the bile duct. The tail of the pancreas is located at the hilus of the spleen, which lies far from the bile duct.
- A 2-year-old boy presents with pain in
his groin that has been increasing in nature over the past few weeks. He is found to have a degenerative malformation of the transversalis fascia during development. Which of the following structures on the anterior abdominal wall is likely defective?
(A) Superficial inguinal ring
(B) Deep inguinal ring
(C) Inguinal ligament
(D) Sac of a direct inguinal hernia
(E) Anterior wall of the inguinal canal
B. The deep inguinal ring lies in the transversalis fascia, just lateral to the infe- rior epigastric vessels. The superficial inguinal ring is in the aponeurosis of the external oblique muscle. The inguinal ligament and the anterior wall of the inguinal canal are formed by the aponeurosis of the external oblique muscle. The sac of a direct inguinal hernia is formed by the peritoneum.
4. A 29-year-old man comes to a local hospital with duodenal peptic ulcer and complains of cramping epigastric pain. Which of the following structures harbors the cell bodies of abdominal pain fibers? (A) Lateral horn of the spinal cord (B) Anterior horn of the spinal cord (C) Dorsal root ganglion (D) Sympathetic chain ganglion (E) Celiac ganglion
C. Cell bodies of the abdominal pain fibers are located in the dorsal root ganglion. The lateral horn of the spinal cord contains cell bodies of sympathetic preganglionic nerve fibers; the anterior horn contains cell bodies of general somatic efferent (GSE) fibers. The sympathetic chain ganglion contains cell bodies of sympathetic postganglionic fibers, which supply blood vessels, sweat glands, and hair follicles. The celiac ganglion contains cell bodies of sympathetic postganglionic fibers, which supply the visceral organs such as stomach and intestine.
- A 42-year-old obese woman with seven children is brought to a local hospital by her daughter. Physical examination and her radiograph reveal that large gallstones have ulcerated through the posterior wall of the fundus of the gallbladder into the intestine. Which of the following parts of the intestine is most likely to initially contain gallstones?
(A) Cecum
(B) Ascending colon (C) Transverse colon
(D) Descending colon
(E) Sigmoid colon
C. The fundus of the gallbladder is in contact with the transverse colon, and thus, gallstones erode through the posterior wall of the gallbladder and enter the transverse co- lon. They are passed naturally to the rectum through the descending colon and sigmoid colon. Gallstones lodged in the body of the gallbladder may ulcerate through the posterior wall of the body of the gallbladder into the duodenum (because the gallbladder body is in contact with the duodenum) and may be held up at the ileocecal junction, producing an intestinal obstruction.
6. 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? (A) Stomach (B) Transverse colon (C) Jejunum (D) Descending colon (E) Spleen
D. The descending colon is a retroperitoneal organ. The rest of the organs are surrounded by peritoneum.
- During an annual health examination of a 46-year-old woman, a physician finds hypersecretion of norepinephrine from her suprarenal medulla. Which of the following types of nerve fibers are most likely overstimulated?
(A) Preganglionic sympathetic fibers
(B) Postganglionic sympathetic fibers
(C) Somatic motor fibers
(D) Postganglionic parasympathetic fibers
(E) Preganglionic parasympathetic fibers
A. The suprarenal medulla is the only organ that receives preganglionic sympathetic fibers. No other nerve fibers are involved in secretion of norepinephrine from the supra- renal medulla.
- A 6-year-old girl comes to her pediatrician with constipation, abdominal distention, and vomiting. After thorough examination, she is diagnosed as having Hirschsprung disease (aganglionic megacolon), which is a congenital disease and leads to dilation of the colon. This condition is caused by an absence of which of the following kinds of neural cell bodies?
(A) Sympathetic preganglionic neuron cell bodies
(B) Sympathetic postganglionic neuron cell bodies
(C) Parasympathetic preganglionic neuron cell bodies
(D) Parasympathetic postganglionic neuron cell bodies
(E) Sensory neuron cell bodies
D. Aganglionic megacolon (Hirschsprung disease) is caused by the absence of enteric ganglia (parasympathetic postganglionic neuron cell bodies) in the lower part of the colon, which leads to dilatation of the colon proximal to the inactive segment, resulting in an inability to evacuate the bowels. The other neuron cell bodies listed are not involved in this condition.
9. A pediatric surgeon is resecting a possible malignant mass from the liver of a neonate with cerebral palsy. The surgeon divides the round ligament of the liver during surgery. A fibrous remnant of which of the following fetal vessels is severed? (A) Ductus venosus (B) Ductus arteriosus (C) Left umbilical vein (D) Right umbilical vein (E) Umbilical artery
C. The left umbilical vein becomes the round ligament of the liver after birth. The right umbilical vein did not leave a fibrous remnant because it was degenerated during the early embryonic period. The ductus venosus forms the ligamentum venosum; the ductus arteriosus forms the ligamentum arteriosum; the umbilical artery forms the medial umbilical ligament.
10. A 27-year-old woman has suffered a gun- shot wound to her midabdomen. After examining the patient’s angiogram, a trauma surgeon locates the source of bleeding from pairs of veins that typically terminate in the same vein. Which of the following veins are damaged? (A) Left and right ovarian veins (B) Left and right gastroepiploic veins (C) Left and right colic veins (D) Left and right suprarenal veins (E) Left and right hepatic veins
E. The right and left hepatic veins drain into the inferior vena cava (IVC). The right gastroepiploic vein drains into the superior mesenteric vein, but the left one drains into the splenic vein. The right gonadal and suprarenal veins drain into the IVC, whereas the left ones drain into the left renal vein. The right colic vein ends in the superior mesenteric vein, but
the left one terminates in the inferior mesenteric vein.
11. A 43-year-old man complains of abdominal pain just above his umbilicus. On examination, a tumor is found anterior to the IVC. Which of the following structures would most likely be compressed by this tumor? (A) Right sympathetic trunk (B) Left third lumbar artery (C) Third part of the duodenum (D) Left renal artery (E) Cisterna chyli
C. The third part of the duodenum (transverse portion) crosses anterior to the IVC. The other structures do not cross the IVC anteriorly.
12. A 33-year-old man with a perforated gastric ulcer complains of excruciating pain in his stomach. It is observed that the pain comes from peritoneal irritation by gastric contents in the lesser sac. Which of the following nerves contain sensory nerve fibers that convey this sharp, stabbing pain? (A) Vagus nerves (B) Greater splanchnic nerves (C) Lower intercostal nerves (D) White rami communicantes (E) Gray rami communicantes
C. Pain sensation originating from peritoneal irritation by gastric contents in the lesser sac is carried by lower intercostals nerves. The vagus nerves carry sensory fibers associated with reflexes in the gastrointestinal (GI) tract. The greater splanchnic nerves and white rami communicantes carry pain (general visceral afferent [GVA]) fibers from the wall of the stomach and other areas of the GI tract. The gray rami communicantes contains no sensory fibers but contain sympathetic postganglionic fibers.
13. A young boy is brought to the hospital after a bicycle accident and possible pelvic fracture. While awaiting a computed tomography (CT) scan of his pelvis, a physician proceeds with a focal neurologic examination. In testing the child’s reflexes, which of the following nerves would carry afferent impulses of the cremasteric reflex? (A) Subcostal nerve (B) Lateral femoral cutaneous nerve (C) Genitofemoral nerve (D) Iliohypogastric nerve (E) Femoral nerve
C. Stimulation of the cremaster muscle draws the testis up from the scrotum toward the superficial inguinal ring. The efferent limb of the reflex arc is the genital branch of the genitofemoral nerve, whereas the afferent limb is the femoral branch of the genitofemoral nerve. The other nerves are not involved in the cremasteric reflex.
- A 21-year-old man receives a penetrating knife wound in the abdomen and is injured in both the superior mesenteric artery and the vagus nerve. Which portion of the colon would most likely be impaired by this injury?
(A) Ascending and descending colons (B) Transverse and sigmoid colons
(C) Descending and sigmoid colons
(D) Ascending and transverse colons
(E) Transverse and descending colons
D. The ascending and transverse colons receive blood from the superior mesenteric artery and parasympathetic nerve fibers from the vagus nerve. However, the descending and sigmoid colons receive blood from the inferior mesenteric artery and the parasympathetic nerve fibers from the pelvic splanchnic nerve arising from sacral spinal nerves (S2–S4).
- A 42-year-old man with portal hypertension secondary to cirrhosis of the liver and subsequent massive ascites presents to the emergency department. He refuses to have a transjugular intrahepatic portosystemic shunt (TIPS) procedure and prefers surgery. Which of the following surgical connections is involved in the most practical method of shunting portal blood around the liver?
(A) Superior mesenteric vein to the inferior mesenteric vein
(B) Portal vein to the superior vena cava (C) Portal vein to the left renal vein
(D) Splenic vein to the left renal vein
(E) Superior rectal vein to the left colic vein
D. Portal hypertension can be reduced by diverting blood from the portal to the caval system. This is accomplished by connecting the splenic vein to the left renal vein or by creating a communication between the portal vein and the IVC. A connection between a hepatic vein and a branch of the portal vein can be accomplished by the transjugular intrahepatic portosystemic shunt (TIPS) procedure in the treatment of bleeding esophageal varices.
- A 78-year-old man is suffering from ischemia of the suprarenal glands. This condition results from rapid occlusion of direct branches of which of the following arteries?
(A) Aorta, splenic, and inferior phrenic arteries
(B) Renal, splenic, and inferior mesenteric
arteries
(C) Aorta, inferior phrenic, and renal arteries
(D) Superior mesenteric, inferior mesenteric,
and renal arteries
(E) Aorta and hepatic and renal arteries
C. The suprarenal gland receives arteries from three sources. The superior suprarenal artery arises from the inferior phrenic artery, the middle suprarenal artery arises from the abdominal aorta, and the inferior suprarenal artery arises from the renal artery. The hepatic, superior mesenteric, inferior mesenteric, and splenic arteries do not supply the suprarenal gland.
- A radiograph of a 32-year-old woman reveals a perforation in the posterior wall of
the stomach in which the gastric contents have spilled into the lesser sac. The general surgeon has opened the lienogastric (gastrosplenic) ligament to reach the lesser sac and notes erosion of the ulcer into an artery. Which of the following vessels is most likely involved?
(A) Splenic artery
(B) Gastroduodenal artery
(C) Left gastric artery
(D) Right gastric artery
(E) Left gastroepiploic artery
E. The left gastroepiploic artery runs through the lienogastric ligament, and hence, it is the artery most likely injured. The splenic artery is found in the lienorenal ligament. The right and left gastric arteries run within the lesser omentum. The gastroduodenal artery descends between the duodenum and the head of the pancreas.
- A 35-year-old woman with a history of cholecystectomy arrives in the emergency department with intractable hiccups most likely caused by an abdominal abscess secondary
to surgical infection. Which of the following nerves carries pain sensation caused by irrita- tion of the peritoneum on the central portion of the inferior surface of the diaphragm?
(A) Vagus nerve
(B) Lower intercostal nerve
(C) Phrenic nerve
(D) Greater splanchnic nerve
(E) Subcostal nerve
C. The diaphragm receives somatic motor fibers solely from the phrenic nerves. However, the peritoneum on the central part of the diaphragm receives sensory fibers from the phrenic nerve, and the peripheral part of the diaphragm receives such fibers from the lower intercostal nerves. The subcostal nerve supplies the peritoneum inferior to the diaphragm. The vagus and greater splanchnic nerves do not carry pain fibers from the peritoneum.
19. A 16-year-old boy with a ruptured spleen comes to the emergency department for splenectomy. Soon after ligation of the splenic artery just distal to its origin, a surgical resident observes that the patient is healing normally. Normal blood flow would occur in which of the following arteries? (A) Short gastric arteries (B) Dorsal pancreatic artery (C) Inferior pancreaticoduodenal artery (D) Left gastroepiploic artery (E) Artery in the lienorenal ligament
C. The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery. All of other arteries are branches of the splenic artery.
20. A9-year-old boy was admitted to the emergency department complaining of nausea, vomiting, fever, and loss of appetite. On examination, he was found to have tenderness and pain on the right lower quadrant. Based on signs and symptoms, the diagnosis of acute appendicitis was made. During an appendectomy performed at McBurney point, which of the following structures is most likely to be injured? (A) Deep circumflex femoral artery (B) Inferior epigastric artery (C) Iliohypogastric nerve (D) Genitofemoral nerve (E) Spermatic cord
C. The iliohypogastric nerve runs medially and inferiorly between the internal oblique and transverse abdominal muscles near the McBurney point, the point at the junction of the lateral one-third of the line between the anterior superior iliac spine and the umbilicus. Other structures are not found near the McBurney point.
- A 54-year-old man with a long history
of alcohol abuse presents to the emergency department with rapidly increasing abdominal distention most likely resulting from an alteration in portal systemic blood flow. Which of the following characteristics is associated with the portal vein or the portal venous system?
(A) Lower blood pressure than in the IVC
(B) Least risk of venous varices because of portal hypertension
(C) Distention of the portal vein resulting from
its numerous valves
(D) Caput medusae and hemorrhoids caused by portal hypertension
(E) Less blood flow than in the hepatic artery
D. Portal hypertension can cause esophageal varices, caput medusa, and hemorrhoids. The portal vein has higher pressure than systemic veins; the vein and its tributaries have no valves, or, if present, they are insignificant. In addition, the portal vein carries two to three times as much blood as the hepatic artery.
- While examining radiographs and angio- grams of a 52-year-old patient, a physician
is trying to distinguish the jejunum from the ileum. He has observed that the jejunum has:
(A) Fewer plicae circulares
(B) Fewer mesenteric arterial arcades
(C) Less digestion and absorption of nutrients
(D) Shorter vasa recta
(E) More fat in its mesentery
B. The jejunum has fewer mesenteric arterial arcades but longer vasa recta than the ileum. The plicae circulares (circular folds) are tall and closely packed in the jejunum and are low and sparse in the ileum, and the lower part of the ileum has no plicae circulares. More digestion and absorption of nutrients occurs in the jejunum than in the ileum, and less fat is found in the mesentery of the jejunum.
23. A 67-year-old woman with a long history of liver cirrhosis was seen in the emergency department. In this patient with portal hypertension, which of the following veins is most likely to be dilated? (A) Right colic vein (B) Inferior epigastric vein (C) Inferior phrenic vein (D) Suprarenal vein (E) Ovarian vein
A. The right colic vein belongs to the portal venous system and empties into the superior mesenteric vein, which joins the splenic vein to form the portal vein. The inferior epi- gastric, inferior phrenic, suprarenal, and ovarian veins belong to the systemic (or caval) venous system and drain directly or indirectly into the IVC.
24. A 26-year-old patient is admitted to a local hospital with a retroperitoneal infection. Which of the following arteries is most likely to be infected? (A) Left gastric artery (B) Proper hepatic artery (C) Middle colic artery (D) Sigmoid arteries (E) Dorsal pancreatic artery
E. The pancreas is a retroperitoneal organ, except for a small portion of its tail. The dorsal pancreatic artery would be the infected artery because it arises from the splenic artery and runs retroperitoneally along the superior border of the pancreas behind the peritoneum. The other arteries run within layers of the peritoneum. The left gastric arteries run within the lesser omentum; the proper hepatic artery runs within the free margin of the lesser omen- tum; the middle colic artery runs within the transverse mesocolon; the sigmoid arteries run within the sigmoid mesocolon.
25. A pediatric surgeon has resected a structure that is a fibrous remnant of an embryonic or fetal artery in a 5-year-old child. Which of the following structures is most likely to be divided? (A) Lateral umbilical fold (B) Medial umbilical fold (C) Median umbilical fold (D) Ligamentum teres hepatis (E) Ligamentum venosum
B. The medial umbilical fold or ligament contains a fibrous remnant of the umbilical artery. The median umbilical fold contains a fibrous remnant of the urachus. The lateral umbilical fold (ligament) contains the inferior epigastric artery and vein, which are adult blood vessels. The ligamentum venosum contains a fibrous remnant of the ductus venosus, and the ligamentum teres hepatic contains a fibrous remnant of the left umbilical vein.