1.
A 41-year-old woman is brought to the ER by her family because of acute onset of right upper quadrant pain, nausea, and vomiting. For this case, it important to remember that the bile duct:
Correct Answer
A. Drains bile into the second part of the duodenum
Explanation
The bile duct is formed by union of the common hepatic and cystic ducts, lies lateral to the proper hepatic artery and anterior to the portal vein in the right free margin of the lesser omentum, traverses the head of the pancreas, and drains bile into the second part of the duodenum at the greater papilla. The endocrine part of the pancreas secretes the hormones insulin and glucagon, which are transported through the bloodstream. The main pancreatic duct carries pancreatic juice containing enzymes secreted from the exocrine part of the pancreas.
2.
A 43-year-old woman is admitted to a hospital because of deep abdominal pain in her epigastric region. On examination, it is observed that a retroperitoneal infection erodes an artery that runs along the superior border of the pancreas. Which of the following arteries is likely injured?
Correct Answer
C. Splenic artery
Explanation
http://upload.wikimedia.org/wikipedia/commons/3/3b/Gray533.pngThe splenic artery arises from the celiac trunk, runs along the superior border of the pancreas, and enters the spleen through the lienorenal ligament and the hilus of the spleen.
The right gastric artery runs along the lesser curvature of the stomach, and
The left gastroepiploic artery runs along the greater curvature of the stomach.
The gastroduodenal artery runs behind the first part of the duodenum.
The dorsal pancreatic artery descends behind the neck of the pancreas and divides into right and left branches to supply the pancreas.
3.
A 58-y/o man is admitted to a hospital with severe abdominal pain, nausea, and vomiting resulting in dehydration. Emergency computed tomography (CT) scan reveals a tumor located between the celiac trunk and the superior mesenteric artery.
Which of the following structures is likely compressed by this tumor?
Correct Answer
B. Neck of the pancreas
Explanation
http://upload.wikimedia.org/wikipedia/commons/3/3b/Gray533.pngThe pyloric canal and the neck of the pancreas are situated anterior to the abdominal aorta between the origin of the celiac trunk and the superior mesenteric artery. The transverse colon passes anterior to the superior mesenteric artery and the third part of the duodenum. The other structures are not located in front of the aorta.
4.
An oncologist is reviewing a computed tomography (CT) scan of a 74-year-old man with newly diagnosed hepatocellular carcinoma. He locates the affected quadrate lobe of the liver that:
Correct Answer
C. Drains bile into the left hepatic duct
Explanation
http://upload.wikimedia.org/wikipedia/commons/a/a3/Gray1087-liver.pngThe quadrate lobe of the liver drains bile into the left hepatic duct and receives blood from the left hepatic artery. It lies between the gallbladder fossa and the ligamentum teres hepatic, is a medial inferior segment, and is a part of the left lobe.
5.
A 46-year-old bakery worker is admitted to a hospital in acute distress. She has experienced severe abdominal pain, nausea, and vomiting for 2 days. The pain, which is sharp and constant, began in the epigastric region and radiated bilaterally around the chest to just below the scapulas. Subsequently, the pain became localized in the right hypochondrium. The patient, who has a history of similar but milder attacks after hearty meals over the past 5 years, is moderately overweight and the mother of four. Palpation reveals marked tenderness in the right hypochondriac region and some rigidity of the abdominal musculature. An x-ray without contrast medium shows numerous calcified stones in the region of the gallbladder. The patient shows no sign of jaundice (icterus). Diffuse pain referred to the epigastric region and radiating circumferentially around the chest is the result of afferent fibers that travel via which of the following nerves?
Correct Answer
A. Greater splanchnic
Explanation
Moore and Dalley, pp 257–258, 322–323.) Visceral afferent pain fibers from the gallbladder travel through the celiac plexus, thence along the greater splanchnic nerves to levels T5–T9 of the spinal cord. Thus, pain originating from the gallbladder will be referred to (appear as if coming from) the dermatomes served by T5–T9, which include a band from the infrascapular region to the epigastrium. If the gallbladder enlarges sufficiently, then pain could be carried by the phrenic nerve (answer c), but this would refer pain to the neck. Intercostal nerves (answer b) would course above the diaphragm and thus are not involved. The vagus (answer d) generally does not transmit pain information. Pelvic splanchinics (answers e) receive pain information from pelvic organs and thus are not involved.
6.
A woman presents with gallstones and no jaundice. She is prepared for exploratory surgery. The lesser omentum is incised close to its free edge, and the biliary tree is identified and freed by blunt dissection. The liquid contents of the gallbladder are aspirated with a syringe, the fundus incised,
and the stones are removed. The entire duct system is carefully probed for stones, one of which is found to be obstructing a duct. In view of her symptoms, where is the most probable location of the obstruction?
Correct Answer
C. The cystic duct
Explanation
(Moore and Dalley, p 304.) Obstruction of any portion of the biliary tree will produce symptoms of gallbladder obstruction. If the common hepatic duct (answer b) or bile duct (answer a) is occluded by stone or tumor, biliary stasis with accompanying jaundice occurs. In addition, blockage of the duodenal papilla (of Vater), distal to the juncture of the bile duct with the pancreatic duct (answer e), can lead to complicating pancreatitis. If only the cystic duct is obstructed, jaundice will not occur because bile
may flow freely from the liver to the duodenum. Bile duct obstruction also may arise as a result of pressure exerted on the duct by an external mass, such as a tumor in the head of the pancreas. Answser d is not anatomically correct.
7.
The lateral umbilical fold serves as the demarcation for whether an inguinal hernia is direct or indirect. The lateral umbilical fold on each side of the inner surface of the anterior abdominal wall is created by which of the following underlying structures?
Correct Answer
B. Inferior epigastric artery
Explanation
(Moore and Dalley, p 231.) Inferior epigastric artery. The lateral umbilical folds are produced by the underlying inferior epigastric arteries as they course from the external iliac artery in the inguinal region toward the rectus sheath. A direct inguinal hernia starts medial to the lateral ambilical fold and an indirect inguinal hernia starts lateral to the same fold. The medial umbilical folds are peritoneal elevations produced by the obliterated umbilical arteries (answer d). In the midline, the median umbilical ligament is formed by the underlying urachus (answer e), a remnant of the embryonic allantois. The Falx inguinalis (answer a) represents inferomedial attachment of transversus abdominis with some fibers of internal abdominal oblique, also known as: conjoint tendon. The lateral border of the rectus sheath (answer c) forms the medial edge of the inguinal triangle.
8.
Mucosal necrosis of the rectum usually will not result from occlusion of the inferior mesenteric artery for which of the following reasons?
Correct Answer
E. The middle rectal artery, a branch of the internal iliac artery, supplies the rectum
Explanation
(Moore and Dalley, p 430.) The rectum receives blood from the superior rectal (hemorrhoidal) artery and from the paired middle and inferior rectal arteries. The superior rectal artery is a direct continuation of the inferior mesenteric artery, but the middle and inferior rectal arteries are branches of the internal iliac artery and continue to supply the distal rectum despite occlusion of the inferior mesenteric artery. It should be noted that Sudeck’s point, between the last sigmoidal artery and the rectosigmoid artery, is an area of potentially weak arterial anastomoses, but that is further cranial. The superior mesenteric artery (answer a) distributes arteries to the small intestine right and middle colic arteries, that supply blood as far distal as the splenic flexure of the transverse colon. The left colic artery (answer b) anastomoses with the sigmoidal arteries. The inferior mesenteric artery supplies the superior rectal artery, so answer c is not correct. The principal branch of the external iliac artery is the femoral
artery (answer e).
9.
Volvulus is most likely to occur within segments of the GI tract that are intraperitoneal, not retroperitoneal. Which segments of the GI tract are susceptible to volvulus, and to where does the referred pain of volvulus tend to occur for that segment?
Correct Answer
E. Sigmoid colon; suprapubic region
Explanation
(Moore and Dalley, pp 277, 257–258.) Volvulus (twisting of the GI tract on itself) which limits movement of material within the lumen and may compromise blood flow occurs most frequently with the jejunum and ileum and the sigmoid colon. These are intraperitoneal segments of the GI tract. The jejunum and ileum are both midgut derivatives and thus refer pain to the periumbilical region [thus not (answer b)]. The sigmoid colon is the most mobile portion of the large bowel and is derived from the hindgut and tends to refer pain to the suprapubic region (especially on the left side) [thus not answers c and d)]. The duodenum (answer a) is retroperitoneal and generally does not undergo volvulus.
10.
A 60-year-old woman arrived at the emergency room complaining of acute abdominal pain. She was diagnosed with ischemic bowel resulting from an obstruction of one or more branches of the inferior mesenteric artery. Which of the following is most likely NOT to be seriously affected by the ischemia?
Correct Answer
A. Cecum
Explanation
The inferior mesenteric artery supplies blood to the end of the transverse colon and all distal structures in the GI tract. This means that the splenic flexure, descending colon, sigmoid colon, and rectum would all be deprived of blood if the inferior mesenteric artery was occluded. The cecum receives blood from the superior mesenteric artery, so it would not be affected by the obstruction
11.
The presence of which feature (also obvious on a radiograph with barium contrast) distinguishes small from large bowel?
Correct Answer
A. Circular folds of the mucosa
Explanation
The small intestine features circular folds of tissue that are covered with villi - these folds are very obvious on a radiograph with barium contrast. The colon does not have similar folds in the mucosa. Some other things that distinguish the small intestine from the large intestine are: 1) The large intestine has 3 strips of longitudinal muscle, called tenia coli, instead of a continuous longitudinal muscle layer the whole way around. 2) The tenia coli are shorter than the colon, so the colon forms bulges, called haustra. 3) The surface of the colon is covered with fatty omental appendages.
The colon and small intestine share similar circular smooth muscle layers and a serosa. Although the gland structure is different in the colon versus the small intestine, this would not be visible on a radiograph. The same goes for the longitudinal muscle layer - there are differences between the two organs, but not ones that you would see on a barium contrast radiograph.
12.
Which is not a boundary of the epiploic (omental) foramen?
Correct Answer
A. Aorta
Explanation
The epiploic (omental) foramen is a passageway between the greater peritoneal sac and the lesser peritoneal sac. It is located posterior to the hepatoduodenal ligament and the first part of the duodenum. The caudate lobe of the liver forms the posterior wall of the epiploic foramen. The aorta is retroperiteoneal, and it does not form a boundary of this foramen
13.
In order to approach the area posterior to the stomach, a surgeon decided to go through the lesser omentum. Before incising the mesentery she was careful to find and preserve a nerve lying in the upper portion of the hepatogastric ligament, i.e., the
Correct Answer
D. Hepatic branch of the anterior vagal trunk
Explanation
The hepatic branch of the anterior vagal trunk travels in the upper portion of the hepatogastric ligament. The posterior vagal trunk supplies a celiac branch deep to the hepatogastric ligament. The greater thoracic splanchnic branches to the suprarenal glands come off the greater thoracic splanchnic nerves as they pass through the diaphragm. Then, the greater thoracic splanchnic nerves continue on to synapse in the celiac ganglia.
14.
During a cholecystectomy (removal of the gall bladder), the surgical resident accidentally jabbed a sharp instrument into the area immediately posterior to the epiploic foramen (its posterior boundary). He was horrified to see the surgical field immediately fill with blood, the source which he knew was the:
Correct Answer
B. Inferior vena cava
Explanation
The epiploic foramen, also called the omental foramen, is the passageway between the greater and lesser peritoneal sacs. The inferior vena cava lies immediately posterior to this foramen, so this is the vessel that was probably cut. The aorta lies next the inferior vena cava, but it is a little more to the left and a little deeper--it does not lie immediately posterior to the epiploic foramen. The hepatic portal vein is anterior to the epiploic foramen. The right renal artery is a branch off of the aorta. Like the aorta, it is too deep to be a vessel immediately behind the foramen. Finally the superior mesentric vein is anterior to the foramen. Remember, this is one of the two vessels that makes the hepatic portal vein, so if the hepatic portal vein is anterior to the foramen, the SMV should be too. (See Netter's 256 for some relevant pictures)
15.
You are observing a laparoscopic cholecystectomy. The surgeon states that he is next going to expose the cystic artery in order to staple across it. He asks you where he should look for it. You reply, "In the triangle of Calot." What stuctures form this triangle and are the keys to finding the artery?
Correct Answer
A. Common hepatic duct, liver and cystic duct
Explanation
The triangle of Calot is formed by the cystic duct laterally, the liver superiorly, and the common hepatic duct medially. It is an important landmark in this region, because the cystic artery can be found in the triangle of Calot. During a cholecystectomy, the cystic artery needs to be ligated. Although the cystic artery usually branches from the right hepatic artery, there is some variation. However, if you locate the triangle of Calot, you can find the cystic artery in that triangle, trace it back to its origin, and then ligate it there.
16.
Regarding the diaphragm, which, is paired INCORRECTLY?
Correct Answer
D. Central tendon - aortic hiatus
Explanation
The aortic hiatus is not in the central tendon of the diaphragm--the caval opening, for the inferior vena cava, is found in the central tendon of the diaphragm. The aortic hiatus is formed by the median arcuate ligament, which unites the two crura of the diaphragm. The vertebrocostal trigone is an area of the diaphragm superior to the lateral arcuate ligament. Here, the diaphragmatic muscle is deficient and the trigone is closed primarily by the inferior and superior fascia of the diaphragm. It is a significant area for hernias. The esophageal hiatus is formed entirely by the fibers of the right crus. The psoas major muscle passes behind the medial arcuate ligament. Finally, the right phrenic nerve passes through the central tendon of the diaphragm, near the vena caval foramen. See Netter Plate 181 for a picture of all these structures and their relationships.
17.
A 19-year-old male suffers a tear to the psoas major muscle during the course of a football game. A scar, which formed on the medial part of the belly of the muscle, involved an adjacent nerve, immediately medial to the muscle. The nerve is called the:
Correct Answer
E. Obturator
Explanation
The obturator nerve runs along the medial border of the psoas major muscle, eventually passing through the obturator canal to innervate muscles of the medial thigh. So, it might be damaged by an injury to the medial portion of psoas major. The femoral nerve runs along the lateral border of psoas major, where psoas major contacts iliacus. The genitofemoral nerve pierces through psoas major at the level of L3 or L4. The iliohypogastric and ilioinguinal nerves run under psoas major, emerging at the lateral border of psoas major to run over quadratus lumborum. The way to distinguish between these two nerves is to remember that the iliohypogastric is superior to the ilioinguinal nerve.
18.
Portal hypertension is defined by a hepatic venous pressure gradient (HVPG) greater than 5 mmHg. It is usually caused by an increase in resistance in the portal-hepatic vascular bed due to obstruction to flow, which is related to cirrhosis in the vast majority of patients. Which of the following veins would contribute for by passing this obstruction?
Correct Answer
B. Left gastric and esopHageal veins
Explanation
The left gastric and esophageal veins would contribute to bypassing the obstruction in portal hypertension. These veins form collateral pathways that allow blood to flow around the obstructed area and relieve the increased pressure in the portal-hepatic vascular bed. This collateral circulation helps to maintain blood flow to the liver and prevent further complications of portal hypertension.
19.
In order to avoid ischemia induced necrosis of the sigmoid colon in a colonectomy procedure, the surgeon had to understand the circulation around the critical point of Sudek. Which two arteries provide the weak anastomosis around this area?
Correct Answer
C. Sigmoid and superior rectal arteries
Explanation
The correct answer is Sigmoid and superior rectal arteries. These two arteries provide a weak anastomosis around the critical point of Sudek, which is important in avoiding ischemia induced necrosis of the sigmoid colon during a colonectomy procedure.
20.
If one were to make an incision parallel to and 2 inches above the inguinal ligament, one would find the inferior epigastric vessels between which layers of the abdominal wall?
Correct Answer
E. Tranversus abdominis muscle and peritoneum
Explanation
The inferior epigastric vessels lay on the inner surface of the transversus abdominis and are covered by parietal peritoneum. Remember, the peritoneum lies over the inferior epigastric vessels to make the lateral umbilical fold. Camper's fascia and Scarpa's fascia are two layers of the superficial fascia - Camper's is the fatty layer and Scarpa's is the membranous layer.
21.
A loop of bowel protrudes through the abdominal wall to form a direct inguinal hernia; viewed from the abdominal side, the hernial sac would be found in which region?
Correct Answer
C. Medial inguinal fossa
Explanation
A direct inguinal hernia passes through the weak fascia in the medial inguinal fossa. This is the area between the medial and lateral umbilical folds (made of the obliterated umbilical artery and inferior epigastric vessels, respectively). A direct inguinal hernia does not pass through the deep inguinal ring or the lateral inguinal fossa--that's what an indirect hernia does. Although it's much more common for an indirect hernia to pass through the superficial inguinal ring, direct hernias could go through this ring too. However, the question is asking you to identify which region the hernia enters on the abdominal side, so superficial inguinal ring is not the correct answer. The supravesicular fossa is between the median and medial umbilical folds--it is formed where the peritoneum reflects from the anterior abdominal wall onto the bladder. Potentially, a very rare external supravesicular hernia could form here.
22.
The boundaries of the inguinal triangle include all except:
Correct Answer
A. Arcuate line
Explanation
The inguinal triangle is the site for direct inguinal hernias. It is defined medially by the lateral border of rectus abdominus, inferiorly by the inguinal ligament, and superiorly by the inferior epigastric artery.
23.
The part of the male reproductive tract which carries only semen within the prostate gland is the:
Correct Answer
E. Ejaculatory duct
Explanation
The ejaculatory duct is a duct which courses through the prostate gland and contains only semen. Remember, semen is the combination of sperm from the ductus deferens, seminal fluid from the seminal vesicle, and secretions of the prostate gland. The ejaculatory duct is formed by the union of the duct of the seminal vesicle and the ampulla of the ductus deferens, and it is the site where sperm and seminal fluid mix. The prostatic urethra is also contained in the prostate gland, and it carries semen, but it also carries urine out of the bladder. The membranous urethra is the continuation of the prostatic urethra outside of the prostate gland, and it carries both semen and urine as well. The seminal vesicle is a structure on the posterior surface of the bladder that produces seminal fluid. The ductus deferens is a passageway that carries sperm from the epididymis to the ejaculatory duct.
24.
Mac, the surgeon, and PC, the anatomist, are fighting about which 1/2 of the liver the caudate and quadrate lobes belong to. What would Mac argue?
Correct Answer
D. Left because they’re left of the IVC
Explanation
http://upload.wikimedia.org/wikipedia/commons/a/a3/Gray1087-liver.pngSurgeons follow the branchings of the portal triad or hepatic veins to divide the liver into 8 segments. Instead of using the falciform ligament, surgeons draw an imaginary line between the IVC and gallbladder as the division between right and left halves.
25.
The nerve supply to the muscles of the anterior abdominal wall:
Correct Answer
C. Travels between the internal oblique and transverses abdominis muscles.
Explanation
The nerve supply to the muscles of the anterior abdominal wall travels between the internal oblique and transversus abdominis muscles.
26.
Which of the following is least likely pertaining to an ileal diverticulum (of Merkel)?
Correct Answer
A. It occurs near the junction between the jejunum and the ileum.
Explanation
The correct answer is "It occurs near the junction between the jejunum and the ileum." This is least likely pertaining to an ileal diverticulum because ileal diverticula are typically found in the ileum, not near the junction between the jejunum and the ileum. The other statements are more likely pertaining to an ileal diverticulum, such as occurring on the antimesenteric border of the ileum, having a cordlike attachment to the umbilicus, potentially causing symptoms similar to appendicitis, and being present in both infants and adults.
27.
The hepatorenal recess (Morison pouch):
Correct Answer
C. Receives infected fluids draining from the omental bursa in the supine position.
Explanation
The hepatorenal recess, also known as Morison pouch, is a potential space located between the liver and the right kidney. It is in the subphrenic recess, which is an area beneath the diaphragm. This recess can receive infected fluids draining from the omental bursa when a person is in a supine (lying flat on their back) position. This can occur in conditions such as peritonitis or abscess formation in the abdominal cavity.
28.
When the sphincter of the bile duct contracts:
Correct Answer
B. Bile is forced into the gallbladder for concentration and storage.
Explanation
When the sphincter of the bile duct contracts, it prevents the flow of bile into the duodenum. Instead, the bile is forced into the gallbladder where it is concentrated and stored for later use. This contraction of the sphincter allows the gallbladder to fill up with bile, which can then be released when needed to aid in the digestion and absorption of fats in the small intestine.
29.
Which of the following is incorrect pertaining to the gall bladder?
Correct Answer
D. During cholecystectomy surgeons typically ligate the left hepatic artery.
Explanation
The incorrect statement pertaining to the gall bladder is that during cholecystectomy surgeons typically ligate the left hepatic artery. Cholecystectomy is the surgical removal of the gall bladder, and ligating the left hepatic artery during this procedure would not be a standard practice. The left hepatic artery supplies blood to the left lobe of the liver, and ligating it could lead to complications such as liver ischemia.
30.
What is true about the Greater Splanchnic Nerve?
Correct Answer
C. Fibers synapse in the celiac ganglia and contribute to the celiac plexus
Explanation
The greater splanchnic nerve provides sympathetic innervation to the adrenal MEDULLA, and receives contributions from spinal levels T5-T9, and modulates the enteric nervous system of the foregut.