Anatomy Questions - GI

While recovering from an open abdominal hysterectomy (i.e., using a midline abdominal incision to gain entry to the pelvis), a patient realizes that she has lost sensation to the skin of her anterior thigh and cannot extend her knee. Retractors holding the incision open and pressing against the posterior abdominal wall most likely caused injury to which nerve? A. Femoral B. Genitofemoral C. Iliohypogastric D. Lateral femoral cutaneous E. Obturator

A. Femoral During open abdominal surgeries (i.e., hysterectomy), retractor blades are used to keep the abdominal cavity open. The blade may come to rest on the femoral nerve as it lies between the iliacus and the lateral side of the psoas major muscle. So, the femoral nerve can be easily injured or crushed during abdominal surgery. If this nerve is injured, the patient will experience some numbness on her leg, and she will be unable to extend her knee. In this case, both the symptoms and the history of abdominal surgery point to damage to the femoral nerve. The genitofemoral nerve pierces the psoas major muscle before entering the pelvis. The iliohypogastric nerve and lateral femoral cutaneous nerve emerge at the lateral border of psoas major and then travel laterally. The obturator nerve is at the medial border of psoas major. None of these other nerves are in the right position to be injured by the retractor blades. For a picture of these nerves of the lumbar plexus, see Netter Plate 464.

The nerve that innervates the cells of the suprarenal medulla consists of fibers of the: A. Greater thoracic splanchnic nerve B. Lesser thoracic splanchnic nerve C. Least thoracic splanchnic nerve D. Anterior vagal trunk E. Posterior vagal trunk

A. Greater thoracic splanchnic nerve The suprarenal medulla is directly innervated by preganglionic sympathetic fibers from the greater thoracic nerve. These fibers synapse on the cells in the adrenal medulla, causing a systemic sympathetic response. Other preganglionic fibers from the greater thoracic nerve synapse in the celiac ganglion; the postganglionic fibers from this ganglion distribute along branches of the celiac trunk. The preganglionic fibers from the lesser thoracic splanchnic nerve synapse in the aorticorenal ganglion--postganglionic processes from this ganglion supply vascular smooth muscle of branches of the renal artery and suprarenal arteries. The preganglionic fibers of the least thoracic splanchnic nerve synapse in the renal plexus. The anterior vagal trunk has a gastric and hepatic branch, supplying parasympathetic fibers to the stomach and liver. The posterior vagal trunk supplies some parasympathetic fibers to the stomach, but it also sends a celiac branch to the celiac plexus. The fibers from the posterior vagal trunk which pass to the celiac plexus eventually distribute to the organs of the abdomen, all the way to the last third of transverse colon.

The nerves that end on the secretory cells of the medulla of the suprarenal glands are principally: A. Preganglionic fibers from the greater thoracic splanchnic nerve B. Postganglionic fibers from the celiac plexus C. Postganglionic fibers from the aorticorenal ganglia D. Preganglionic fibers from the lesser thoracic splanchnic nerve E. Postganglionic fibers from the renal plexus

A. Preganglionic fibers from the greater thoracic splanchnic nerve Preganglionic fibers from the greater thoracic splanchnic nerve directly innervate the suprarenal medulla, causing a systemic sympathetic response. Postganglionic sympathetic axons from the celiac plexus distribute along branches of the celiac trunk to supply the vascular smooth muscle of those arteries. Preganglionic fibers from the lesser thoracic splanchnic nerve travel to the aorticorenal ganglia; postganglionic fibers from the aorticorenal ganglia supply the vascular smooth muscle of the branches of the renal arteries. The postgangionic fibers from the renal plexus provide sympathetic innervation to smooth muscle to the blood vessels supplying the kidney, renal pelvis and upper ureter.

Blood from an injured kidney will seep through the perirenal fat until it contacts the internal surface of the renal (Gerota's) fascia. Without perforating this fascia the blood could then continue to pass in what direction? A. inferiorly toward the pelvis B. laterally into the body wall C. medially across the midline to the other kidney D. superiorly into contact with the fascia of the diaphragm

A. inferiorly toward the pelvis The kidney is surrounded by a perirenal fatty capsule, the renal (Gerota's) fascia and pararenal fat. The fat offers no resistance to hemorrhage, but blood is contained in the renal fascia. This means that blood would not flow toward the body wall, other kidney, or toward the diaphragm. However, a kidney injury might involve part of the urinary collecting system, and blood from such damage would travel into the ureters and bladder.

The vagus nerve passes into the abdomen by passing through the A. Aortic hiatus B. Esophageal hiatus C. Caval foramen D. Lateral arcuate ligament E. Medial arcuate ligament

B. Esophageal hiatus Remember back to the thorax--the vagus joins the esophageal plexus and covers the esophagus. The anterior and posterior vagal trunks form from the esophageal plexus-- they pass into the abdomen through the esophageal hiatus, on the anterior and posterior surfaces of the esophagus. The aortic hiatus is deep to the median arcuate ligament--it transmits the aorta and the thoracic duct. The caval foramen is found in the central tendon of the diaphragm; it transmits the inferior vena cava. Psoas major is deep to the medial arcuate ligament, and quadratus lumborum is deep to the lateral arcuate ligament.

The pararenal fat in the kidney bed is an elaboration of: A. Peritoneum B. Extraperitoneal connective tissue C. Transversalis fascia D. Fusion fascia

B. Extraperitoneal connective tissue Each kidney is embedded in two layers of fat, with a membrane (the renal fascia), in between the layers. Inside the renal fascia, and directly atop the kidney, is the perirenal fat. Outside the renal fascia, you will find the pararenal fat, which is an elaboration of extraperitoneal connective tissue. Although the kidney is not peritonealized, the peritoneum from the posterior body wall lies over the anterior surface of the pararenal fat. The kidney is not a secondarily retroperitoneal organ--it began development in the retroperitoneum. So, it does not have a fusion fascia.

In the lumbar region, tuberculosis may spread from the vertebrae into an adjacent muscle to produce an abscess. Pus from the abscess may travel within the fascial sheath surrounding the affected muscle. A patient presents with pus surfacing in the superomedial part of the thigh. To which muscle did the tuberculosis most likely spread? A. Internal oblique B. Obturator internus C. Psoas major D. Quadratus lumborum E. Rectus abdominis

C. Psoas major This patient has Pott's disease, which is tuberculosis of the spine. Tuberculosis of the spine frequently occurs in untreated tuberculosis in young individuals, especially those on a poor diet. The tubercle bacilli enter through the respiratory tract and pass from lungs to systemic circulation. The bacilli tend to lodge in the bone marrow of the spine, including the lumbar vertebrae. An infection in the lumbar vertebrae may pass to the psoas major muscle, since psoas major takes origin from the lumbar vertebrae. This infection can cause an abscess in psoas major, which will be contained by the fascial sheath of the muscle. The psoas major muscle arises from the bodies of the lumbar vertebrae, passes under the inguinal ligament, and joins with the iliacus to insert on the lesser trochanter of the femur as the iliopsoas tendon. Psoas major passes through the superomedial part of the thigh, so an infection in this muscle matches with the location of the pus. None of the other muscles are closely associated with the lumbar vertebrae or found in the superomedial thigh, so they could not have been ones infected.

With one exception, preganglionic sympathetic axons synapse upon postganglionic sympathetic dendrites or cell bodies. The exception to this general rule occurs within the: A. Kidney cortex B. Kidney medulla C. Suprarenal medulla D. Suprarenal cortex

C. Suprarenal medulla The suprarenal medulla is directly innervated by preganglionic sympathetic fibers from the greater thoracic splanchnic nerve. These preganglionic fibers synapse on the cells of the adrenal medulla, causing the cells in the adrenal medulla to release norepinephrine and/or epinephrine. The preganglionic fibers can synapse on these cells of the adrenal medulla because they are modified nervous tissue. The epinephrine and norepinepherine enters the blood stream to cause a systemic response.

The cisterna chyli accompanies which structure as it passes through the diaphragm? A. Inferior vena cava B. Esophagus C. Greater thoracic splanchnic nerve D. Aorta

D. Aorta In 25-50% of cases, the inferior portion of the thoracic duct includes a dilated portion called the cisterna chyli. When present, all of the lymph trunks draining the abdomen and lower limbs dump into it, as well as the most inferior intercostal lymph trunks. When it is not present, these trunks simply empty into the thoracic duct. So, the cisterna chyli is a portion of the thoracic duct, and the thoracic duct passes through the diaphragm with the aorta at the T12 level. The inferior vena cava passes through the central tendon of the diaphragm at the T8 level. The esophagus and vagal branches pass through the right crus of the diaphragm at the T10 level. The greater thoracic splanchnic nerves pass through the fibers of the left and right crus.

Regarding the diaphragm, which, is paired INCORRECTLY? A. Vertebrocostal trigone - lateral arcuate ligament B. Esophageal hiatus - right crus C. Medial arcuate ligament - psoas muscle D. Central tendon - aortic hiatus E. Vena caval foramen - right phrenic nerve

D. Central tendon - aortic hiatus 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.

The nerves of the lumbar plexus are arranged around specific muscles of the posterior abdominal wall. Which of these nerves lies immediately medial to the psoas major muscle? A. Femoral B. Genitofemoral C. Ilioinguinal D. Obturator

D. Obturator The obturator nerve lies along the medial border of the psoas major muscle. The femoral nerve lies along the lateral border of the psoas major muscle, between psoas major and iliacus. The genitofemoral nerve pierces psoas major then lies on top of that muscle. The ilioinguinal nerve emerges at the lateral border of psoas major, then travels laterally.

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: A. femoral B. genitofemoral C. iliohypogastric D. ilioguinal E. obturator

E. obturator During open abdominal surgeries (i.e., hysterectomy), retractor blades are used to keep the abdominal cavity open. The blade may come to rest on the femoral nerve as it lies between the iliacus and the lateral side of the psoas major muscle. So, the femoral nerve can be easily injured or crushed during abdominal surgery. If this nerve is injured, the patient will experience some numbness on her leg, and she will be unable to extend her knee. In this case, both the symptoms and the history of abdominal surgery point to damage to the femoral nerve. The genitofemoral nerve pierces the psoas major muscle before entering the pelvis. The iliohypogastric nerve and lateral femoral cutaneous nerve emerge at the lateral border of psoas major and then travel laterally. The obturator nerve is at the medial border of psoas major. None of these other nerves are in the right position to be injured by the retractor blades. For a picture of these nerves of the lumbar plexus, see Netter Plate 464.

A radiological examination of a patient revealed a large tumor in the quadrate lobe of the liver. During the surgical removal of the tumor, one of the vessels that needs to be clamped to effectively control bleeding is the: A. Left hepatic artery B. Right hepatic artery

A. Left hepatic artery The left and right hepatic arteries help support the parenchyma and stroma of the liver. The left hepatic artery supplies the left & quadrate lobes of liver, and part of the caudate lobe. The right hepatic artery supplies the right lobe and part of the caudate lobe. So, the left hepatic artery must be clamped to perform surgery on the quadrate lobe.

The blockage of a main bile duct in the quadrate lobe will likely cause reduced flow of bile secretion in the: A. Left hepatic duct B. Right hepatic duct

A. Left hepatic duct Like the left hepatic vein, the left hepatic duct drains bile from the left lobe, quadrate lobe, and part of the caudate lobe of the liver. So, an obstruction in the quadrate lobe would reduce bile secretion in the left hepatic duct. The right hepatic duct and hepatic vein drain the right lobe and part of the caudate lobe.

Which is not a boundary of the epiploic (omental) foramen? A. Aorta B. Caudate lobe of the liver C. First part of the duodenum D. Hepatoduodenal ligament

A. Aorta 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.

The posterior layer of the rectus sheath ends inferiorly at the A. Arcuate line B. Intercrestal line C. Linea alba D. Pectineal line E. Semilunar line

A. Arcuate line The arcuate line is an anatomical feature on the inner surface of the abdominal wall. It is the point at which the posterior lamina of the rectus sheath ends and transversalis fascia lines the inner surface of rectus abdominis. The intercrestal line is an imaginary line drawn in the horizontal plane at the upper margin of the iliac crests. It is a landmark used to find the L4 vertebra, which is useful when performing a spinal tap. Linea alba is an aponeurotic band on the midline of the anterior abdominal wall, which extends from the xiphoid process to the pubic symphysis. It is formed by the combined abdominal muscle aponeuroses, and it provides a useful site for a midline incision in the abdomen. The pectineal line is a structural feature of the pubic bone. It is an oblique ridge on the lateral part of the superior ramus. Finally, the semilunar line is the lateral margin of the rectus abdominis, formed by the fused aponeuroses of the abdominal wall muscles at the lateral margin of the rectus sheath.

The boundaries of the inguinal triangle include all except: A. Arcuate line B. Inferior epigastric vessels C. Inguinal ligament D. Lateral border of rectus abdominus muscle

A. Arcuate line 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.

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? A. Cecum B. Descending colon C. Rectum D. Sigmoid colon E. Splenic flexure

A. Cecum 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.

The presence of which feature (also obvious on a radiograph with barium contrast) distinguishes small from large bowel? A. Circular folds of the mucosa B. Circular smooth muscle layer in the wall C. Mucosal glands D. Longitudinal smooth muscle layer in the wall E. Serosa

A. Circular folds of the mucosa 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.

A patient with jaundice was diagnosed with cancer of the head of the pancreas. Which structure was compressed by the tumor? A. Common bile duct B. Common hepatic duct C. Cystic duct D. Left hepatic duct E. Right hepatic duct

A. Common bile duct Tumors in the head of the pancreas often obstruct the common bile duct, blocking the normal bile recycling circuit. This blockade prevents excretion of bilirubin, a yellow-colored pigment that is a red blood cell breakdown product. The accumulation of bilirubin in various tissues, including the skin, causes jaundice. A tumor in the head of the pancreas would not block the other ducts--look at Netter 276 to see how all the ducts are related.

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? A. Common hepatic duct, liver and cystic duct B. Cystic duct, right hepatic artery and right hepatic duct C. Gall bladder, liver and common bile duct D. Left hepatic duct, liver and cystic duct E. Right branch of portal vein, liver and common bile duct

A. Common hepatic duct, liver and cystic duct 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.

The spleen: A. Develops in the dorsal mesogastrium B. Develops in the ventral mesogastrium C. Develops in both the dorsal and ventral mesogastria D. Is always retroperitoneal E. Becomes retroperitoneal during its development

A. Develops in the dorsal mesogastrium The spleen and pancreas develop behind the stomach in the dorsal mesogastrium; the liver develops in the ventral mesogastrium. The spleen is not a retroperitoneal organ--it is covered by visceral peritoneum on all its surfaces.

A Kocher manuever dissects in the avascular plane behind which organ that becomes retroperitoneal during rotation of the gut? A. Duodenum B. Kidney C. Spleen D. Suprarenal gland E. Transverse colon

A. Duodenum A Kocher maneuver involves reflecting the duodenum and pancreas medially by cutting through the fusion fascia along the right side of the descending part of the duodenum. This technique is used to gain access behind the pancreas. However, even if you didn't know the exact definition of a Kocher maneuver, you could still answer this question. The question is asking you to pick which organ is secondarily retroperitoneal, and the only secondarily retroperitoneal organ listed is the duodenum. The kidney and suprarenal gland were retroperitoneal during the entire developmental process, and the transverse colon and spleen are peritonealized. So, duodenum is the only answer that makes sense here.

To stop hemorrhaging from a ruptured spleen, it was necessary to temporarily ligate the splenic artery near the celiac trunk. The blood supply to which structure is least likely to be affected by the ligation? A. Duodenum B. Greater omentum C. Body of pancreas D. Tail of pancreas E. Stomach

A. Duodenum The duodenum receives blood from the gastroduodenal artery, a branch of the common hepatic artery. It also receives blood from the inferior pancreatoduodenal artery, which is a branch of the superior mesenteric artery. So, the duodenum is receiving blood from the common hepatic artery and the superior mesenteric artery, but it is not receiving any blood from the splenic artery. The splenic artery supplies blood to the body of the pancreas with the dorsal and superior pancreatic arteries; it supplies blood to the tail of the pancreas with the caudal pancreatic artery. The splenic artery supplies the fundus of the stomach with short gastric arteries and the left portion of the greater curvature with the left gastroomental artery. The left gastroomental artery also supplies blood to the greater omentum through omental branches. All of these structures would be affected if the splenic artery was ligated.

A patient was admitted with symptoms of bowel obstruction. Further examination revealed that the obstruction was caused by the nutcracker-like compression of the bowel between the superior mesenteric artery and the aorta. The compressed bowel is most likely the: A. Duodenum B. Jejunum C. Ileum D. Ascending colon E. Transverse colon

A. Duodenum The superior mesenteric artery crosses over the third part of the duodenum, and the aorta is posterior to the third part of the duodenum. If something causes these vessels to become enlarged, they can crush the duodenum, and food will not be able to pass through the duodenum. This is often called the "nutcracker effect," and it is only seen in the third part of the duodenum. Take a look at Netter Plate 292 for an illustration of the third part of the duodenum lying between these important vessels.

The structure that traverses the space between the aorta and first part of the superior mesenteric artery and is vulnerable to the nutcracker-like compression by these two vessels is the: A. Duodenum B. Jejunum C. Pancreas D. Splenic vein E. Transverse colon

A. Duodenum The superior mesenteric artery crosses over the third part of the duodenum, and the aorta is posterior to the third part of the duodenum. If something causes these vessels to become enlarged, they can crush the duodenum, and the passage of food will be obstructed. This is often called the "nutcracker effect," and it is only seen in the third part of the duodenum. Take a look at Netter Plate 292 for an illustration of the third part of the duodenum lying between these important vessels.

Which organ becomes retroperitoneal during rotation of the gut tube? A. Duodenum B. Kidney C. Spleen D. Stomach E. Transverse Colon

A. Duodenum This question is asking you to identify the organ that is secondarily retroperitoneal. This means that it started out peritonealized but became pressed against the posterior body wall and stuck there during development. Except for the first few centimeters of the superior segment and the duodenojejunal junction, the duodenum is a secondarily retroperitoneal organ - it used to have a mesentery, but that was lost during gut rotation. Although the kidney is a retroperitoneal organ, it is not secondarily retroperitoneal - it started developing in the retroperitoneum and stayed there. The spleen, stomach, and transverse colon are all peritonealized. What segments of the colon are peritonealized? The cecum, transverse colon, and the sigmoid colon are peritoneal, but the ascending and descending colon are retroperitoneal.

You were asked to assist in a surgical operation on a young patient to treat an ulcer in the first part of the duodenum. You would expect that the surgeon will approach the ulcer by doing an anterior abdominal wall incision in the following region: A. Epigastric B. Left inguinal C. Left lumbar D. Right hypochondrial E. Hypogastric

A. Epigastric The epigastric region is one of the nine regions of the abdomen. It contains the duodenum, part of the stomach, part of the liver, and the pancreas. This is the region that the surgeon would need to enter to reach the ulcer in the first part of the duodenum. The left inguinal region contains the sigmoid colon. The left lumbar region contains the descending colon and kidney. The right hypochondrial region contains part of the liver and the gall bladder. Finally, the hypogastric region contains the bladder and rectum.

A 50-year-old female patient with severe jaundice was diagnosed with pancreatic cancer. You suspect that the tumor is located in which portion of the pancreas? A. Head B. Neck C. Body D. Tail E. Uncinate process

A. Head Tumors in the head of the pancreas often obstruct the common bile duct, blocking the normal bile recycling circuit. This blockade prevents excretion of bilirubin, a yellow-colored pigment that is a red blood cell breakdown product. The accumulation of bilirubin in various tissues, including the skin, causes jaundice. Tumors in other areas of the pancreas are not as likely to block the common bile duct and cause jaundice.

The spleen contacts all of the following organs EXCEPT: A. Jejunum B. Kidney C. Left colic flexure D. Tail of the pancreas E. Stomach

A. Jejunum The spleen is not in contact with the jejunum. The jejunum lies medial and inferior to the spleen. The kidney is in contact with the posteromedial surface of the spleen. The left colic flexure is in contact with the inferomedial surface of the spleen. The tail of the pancreas touches the hilum of the spleen. The stomach is in contact with the anteromedial surface of the spleen. See Netter Plate 289 for a picture of the different impressions on the spleen.

A medical student was asked to identify a small specimen taken for pathological examination from a surgically removed duodenum. The student noted that the specimen revealed a thin wall and no circular folds. The specimen is from which segment? A. Superior B. Descending C. Horizontal D. Ascending

A. Superior The superior part of the duodenum is the one segment of the duodenum that has no circular folds. When food enters the duodenum from the pyloric sphincter, it enters the ampulla, which is a smooth area of the duodenum containing a high percentage of mucosal cells. These cells secrete mucus to neutralize the acidic contents of the stomach. If the stomach contents is not sufficiently neutralized, the thin wall of the ampulla may develop an ulcer. If the ulcer burns through the entire wall, it might jeopardize the gastroduodenal artery, lying behind the first segment of the duodenum. The descending, horizontal, and ascending portions of the duodenum all have circular folds. For an illustration of the different linings of the duodenum, see Netter Plate 262.

A 70-year-old man with cancer of the ascending colon was admitted to the hospital for tumor removal. The surgeon may perform any of these surgical procedures EXCEPT: A. an incision in the left lower quadrant to access the tumor. B. examination of the superior mesenteric lymph nodes for possible metastasis. C. ligation of the relevant branches of the superior mesenteric artery. D. mobilization of the concerned intestinal segment by freeing its fusion fascia. E. protect the peritoneum from possible fecal contamination.

A. an incision in the left lower quadrant to access the tumor. The ascending colon is on the right side of the abdomen--the surgeon would not need to explore the left lower quadrant! Because the ascending colon is supplied by the superior mesenteric artery, the surgeon might need to ligate branches of this artery, and the surgeon would also want to check the superior mesenteric nodes for metastasis. Since the ascending colon is secondarily retroperitoneal, it can be mobilized by freeing its fusion fascia. Finally, it's always a good idea to protect the peritoneum from fecal contamination!

During exploratory abdominal surgery on a 55-year-old male complaining of right lower quadrant pain, the surgeon initially sees no appendix but knows that he can quickly locate it by A. looking at the confluence of the teniae coli B. palpating the ileocecal valve and looking just above it C. following the course of the right colic artery D. removing the right layer of the mesentery of the jejunoileum E. palpating and inspecting the pelvic brim

A. looking at the confluence of the teniae coli The teniae coli are three bands of longitudinal muscle on the surface of the large intestine. Remember, the large intestine does not have a continuous layer of longitudinal muscle - instead, it has teniae coli. These three bands meet at the appendix, which is the terminal portion of the cecum. The appendix is below the ileocecal valve, not above it. It is not near the right colic artery, which supplies the ascending colon. The appendix would not be found by removing a layer of the mesentery of the jejunoileum - in fact, the appendix has its own mesentery, the mesoappendix. Finally, the appendix is not on the pelvic brim.

During your peer presentation of the inguinal region dissection, you would indicate the position of the deep inguinal ring to be: A. Above the anterior superior iliac spine B. Above the midpoint of the inguinal ligament C. Above the pubic tubercle D. In the supravesical fossa E. Medial to the inferior epigastric artery

B. Above the midpoint of the inguinal ligament The deep inguinal ring is found near the midpoint of the inguinal ligament, below the anterior superior iliac spine. This ring is lateral to the inferior epigastric artery. The superficial inguinal ring is found above the pubic tubercle. Remember--the supravesical fossa is the space between the median and medial umbilical folds.

The terminal ends of the ilioinguinal nerves in the female are referred to as: A. Anterior cutaneous branches B. Anterior labial C. Cremasterics D. Iliohypogastrics

B. Anterior labial The ilioinguinal nerves supply motor and sensory fibers to the abdominal wall inferior to the umbilicus. What differentiates these nerves from the iliohypogastric nerves is that the ilioinguinal nerves also innervate the scrotum or labia by passing through the inguinal canal. These branches are called the anterior scrotal or labial nerves. Anterior cutaneous branches pretty much describes what these branches are, but there's an answer here that is a little more specific. The genital branch of the genitofemoral nerve innervates the cremaster muscle.

The skin of the mons pubis is supplied by which nerve? A. Anterior scrotal B. Anterior labial C. Femoral branch of the genitofemoral D. Iliohypogastric nerve E. Subcostal nerve

B. Anterior labial The anterior labial nerve (anterior scrotal in males) is the terminal branch of the ilioinguinal nerve. It innervates the skin of the mons pubis in females and the skin of the anterior scrotum in males. The femoral branch of the genitofemoral nerve provides sensory innervation to the upper medial thigh. The iliohypogastric nerve innervates muscles of the abdominal wall. The subcostal nerve is the ventral primary ramus of the twelfth thoracic nerve. It innervates muscles of the abdominal wall and skin of the lower abdominal wall.

During exploratory surgery of the abdomen, an incidental finding was a herniation of bowel between the lateral edge of the rectus abdominis muscle, the inguinal ligament and the inferior epigastric vessels. These boundaries defined the hernia as a(n): A. Congenital inguinal hernia B. Direct inguinal hernia C. Femoral hernia D. Indirect inguinal hernia E. Umbilical hernia

B. Direct inguinal hernia The boundaries listed in this question are the boundaries of the inguinal triangle, which is the site for direct inguinal hernias. Remember--direct inguinal hernias protrude through the weak fascia of the abdominal wall, medial to the inferior epigastric vessels. Indirect inguinal hernias (which can also be called congenital inguinal hernias) occur lateral to the inferior epigastric vessels--they protrude through the deep inguinal ring. Femoral hernias protrude through the femoral ring, into the femoral canal. They can be felt in the femoral triangle, inferior to the pubic tubercle. Finally, an umbilical hernia is an abnormal protrusion of abdominal contents into a defect in the umbilical area. These are common in the newborn, but they usually resolve by age two.

A surgeon has decided to perform a segmental resection of the descending colon on a 70-year-old man with intestinal cancer. In principle, any of these surgical procedures might be necessary EXCEPT: A. An extended left lower quadrant incision to approach the descending colon. B. Examining the sacral lymph nodes for possible enlargement. C. Ligation of the relevant left colic artery branches. D. Mobilizing the concerned intestinal segment by freeing its fusion fascia. E. Protecting the peritoneum from possible fecal contamination.

B. Examining the sacral lymph nodes for possible enlargement. The descending colon drains into the inferior mesenteric nodes--these are the lymph nodes that the surgeon would want to check for enlargement, not the sacral nodes. The descending colon can be approached from the lower left quadrant. It is a secondarily retroperitoneal organ, so it can be mobilized by freeing fusion fascia. It would also be important to ligate branches of the left colic artery, since this is the branch of the inferior mesenteric that supplies the descending colon. And, obviously, the peritoneum should be protected from fecal contamination!

A 60-year-old male executive who had a history of a chronic duodenal ulcer was admitted to the ER exhibiting signs of a severe internal hemorrhage. He was quickly diagnosed with perforation of the posterior wall of the first part of the duodenum and erosion of an artery behind it by the gastric expellent. The artery is most likely the: A. Common hepatic B. Gastroduodenal C. Left gastric D. Proper hepatic E. Superior mesenteric

B. Gastroduodenal For a good understanding of this question, take a look at Netter Plate 290. The gastroduodenal artery is a branch of the common hepatic artery; it descends behind the first part of the duodenum. So, if an ulcer destroyed the posterior wall of the duodenum, gastric juices could escape and destroy the gastroduodenal artery. The common hepatic artery is a branch of the celiac trunk found superior to the duodenum. The left gastric artery is a branch of the celiac trunk which supplies the left side of the lesser curvature of the stomach. The proper hepatic artery is a branch of the common hepatic artery; it travels superiorly from the common hepatic artery to give off the right, middle, and left hepatic arteries. Finally, the superior mesenteric artery originates from the aorta at the bottom of the L1 level, posterior to the pancreas. It travels over the 3rd part of the duodenum and supplies the intestines, up to the last third of the transverse colon.

A 60-year-old patient who has had a chronic ulcer of the duodenum for many years was admitted to the hospital with signs of a severe internal hemorrhage. The ulcer perforated the posterior wall of the first portion of the duodenum and eroded an artery in that position. The damaged artery was: A. Cystic B. Gastroduodenal C. Hepatic D. Left gastric

B. Gastroduodenal The gastroduodenal artery is a branch of the common hepatic artery--it passes immediately posterior to the first portion of the duodenum, and it can be damaged if there is an ulcer in this part ot the duodenum. The cystic artery supplies the gall bladder--it can be located in the triangle of Calot. The proper hepatic artery is a branch of the common hepatic artery--it travels superior to the first portion of the duodenum. The left gastric artery is a branch of the celiac trunk--it supplies the left side of the lesser curvature of the stomach.

Following an emergency appendectomy your patient complained of having paresthesia (numbness) of the skin at the pubic region. The most likely nerve that has been injured during the operation is: A. Genitofemoral B. Iliohypogastric C. Subcostal D. Spinal nerve T10 E. Spinal nerve T9

B. Iliohypogastric The iliohypogastric nerve is a branch of the lumbar plexus. It provides sensory innervation to the skin of the lower abdominal wall, upper hip and upper thigh. This is the region where the patient is experiencing paresthesia, so this nerve must be injured. The genitofemoral nerve is another nerve from the lumbar plexus. It provides sensory innervation to the skin of the anterior scrotum or labia majora and upper medial thigh. The subcostal nerve is the ventral primary ramus of T12--it is the equivalent of an intercostal nerve at a higher thoracic level. It provides sensory innervation to the anterolateral abdominal wall, but in an area superior to the pubic region. A spinal nerve would not have been injured in the operation. Remember--the spinal nerve is just that small segment of nerve that exists once the dorsal and ventral rootlets come together, before the dorsal and ventral primary rami branch off. In any case, the T9 and T10 dermatomes are superior to the area where the patient is experiencing paresthesia.

Which nerve passes through the superficial inguinal ring and may therefore be endangered during inguinal hernia repair? A. Femoral branch of the genitofemoral B. Ilioinguinal C. Iliohypogastric D. Obturator E. Subcostal

B. Ilioinguinal The ilioinguinal nerve enters the inguinal canal from the side (instead of passing through the deep inguinal ring). It leaves the inguinal canal by passing through the superficial inguinal ring to exit the canal, so it might be injured during inguinal hernia repair. The femoral branch of the genitofemoral nerve travels lateral to the superficial inguinal ring. The iliohypogastric nerve and the subcostal nerve travel superior to the inguinal canal and superficial inguinal ring. Finally, the obturator nerve is a branch of the lumbar plexus which innervates muscles in the thigh. To reach the thigh, this nerve travels deep to the inguinal canal, and it is not involved with this region. See Netter Plate 249 for an illustration of these nerves.

If a hernia enters into the scrotum, it is most likely a(n): A. Direct inguinal hernia B. Indirect inguinal hernia C. Femoral hernia D. Obturator hernia

B. Indirect inguinal hernia Indirect inguinal hernias cross through the deep inguinal ring, passing deep to the internal spermatic fascia. This means that they can enter the scrotum fairly easily, and indirect inguinal hernias are often found in the scrotum. Direct inguinal hernias are not covered by the internal spermatic fascia; they enter the inguinal canal next to the spermatic cord, and rarely enter the scrotum. (However, direct inguinal hernias can enter the scrotum on rare occasion, so don't assume that you are dealing with an indirect inguinal hernia just because it has entered the scrotum.) A femoral hernia is protrusion of abdominal viscera through the femoral ring into the femoral canal. It appears as a mass in the femoral triangle, inferolateral to the pubic tubercle. An obturator hernia is a protrusion of a loop of bowel through the obturator canal.

The internal thoracic artery is sometimes surgically cut near the caudal end of the sternum and used to supply blood to a region of the heart. In these cases, maintenance of adequate blood flow to the rectus abdominis may be dependent on increased flow through which artery? A. Superficial epigastric B. Inferior epigastric C. Umbilical D. Superficial circumflex iliac E. Deep circumflex iliac

B. Inferior epigastric If the internal thoracic artery was ligated, blood would no longer flow to the superior epigastric artery, which is the branch of the internal thoracic that supplies blood to rectus abdominis. However, the superior epigastric artery communicates with the inferior epigastric artery, a branch of the external iliac artery. This means that blood could flow from the external iliac, to the inferior epigastric, to the superior epigastric and the rectus abdominis. The superficial epigastric and superficial circumflex iliac arteries are two superficial branches of the femoral artery. They do not supply deep structures in the abdomen. The distal portions of the umbilical arteries are obliterated in adults--they are the medial umbilical ligaments that form the medial umbilical folds. The deep circumflex iliac artery courses along the iliac crest on the inner surface of the abdominal wall. It is too lateral to supply blood to rectus abdominis.

In order to reduce a hernia (return it to the abdominal cavity), a surgeon finds it necessary to ligate an artery in the extraperitoneal connective tissue (preperitoneal fat) running vertically just medial to the bowel as the bowel passes through the abdominal wall. This artery is the: A. Deep circumflex iliac B. Inferior epigastric C. Superficial circumflex iliac D. Superficial epigastric E. Superficial external pudendal

B. Inferior epigastric The inferior epigastric vessels are found in the preperitoneal fat of the abdomen. They lie just superficial to the peritoneum and form the lateral umbilical fold. Hernias may pass lateral or medial to these vessels. If the hernia is lateral to the vessels (which is what happened in this case), it is an indirect inguinal hernia. If the hernia is medial to these vessels, it is a direct inguinal hernia. The deep circumflex artery courses along the iliac crest on the inner surface of the abdominal wall. This artery is very lateral on the abdominal wall, and hernias would pass medial to this vessel. The superficial circumflex iliac, superficial epigastric, and superficial external pudendal arteries are all superficial arteries that arise from the femoral artery. They are all found in the superficial fascia--not in the preperitoneal fat.

A 45-year-old porter develops a direct inguinal hernia. If the hernia extended through the superficial inguinal ring, it would be surrounded by all of the abdominal wall layers EXCEPT the: A. External spermatic fascia B. Internal spermatic fascia C. Peritoneum and extraperitoneal connective tissue D. Weak fascia of the transversus abdominis muscle E. lateral to the falx

B. Internal spermatic fascia The internal spermatic fascia is derived from the transversalis fascia. As the testes descend through the deep inguinal ring, the transversalis fascia is pulled along, forming the innermost covering of the spermatic cord. So, in an adult, the spermatic cord is lying in the inguinal canal, covered by the internal spermatic fascia. Now, think about what happens in the direct inguinal hernia--a piece of bowel begins to protrude through the weak fascia on the posterior wall of the inguinal canal. But at that location, the spermatic cord is already lying in the inguinal canal, covered by the internal spermatic fascia. This means that the direct inguinal hernia will lie next to the spermatic cord, but it cannot enter the spermatic cord. In contrast, an indirect inguinal hernia passes through the deep inguinal ring, and it will be covered by the internal spermatic fascia of the spermatic cord. Both types of hernias are covered by the external spermatic fascia, the peritoneum, and extraperitoneal connective tissue. The direct inguinal hernia passes through the weak fascia of transversus abdominus, so it would be covered by that layer which is absent from an indirect inguinal hernia.

Regarding the 2nd portion of the duodenum, all are correct EXCEPT: A. It is crossed by the transverse colon. B. It is thin walled and circular folds are absent in its interior. C. It has the opening for the common bile duct and pancreatic duct on its posteromedial wall. D. It is secondarily retroperitoneal. E. It is supplied by both the gastroduodenal and superior mesenteric arteries.

B. It is thin walled and circular folds are absent in its interior. The first part of the duodenum features thin walls and no circular folds. It is called the ampulla of the duodenum. Once the duodenum turns and becomes the second part, the walls become thicker, and circular folds develop. The second part of the duodenum has the hepatopancreatic ampulla in its medial wall, which is the duct formed as the common bile duct and pancreatic duct join to empty their secretions into the duodenum. The transverse colon overlies the second part of the duodenum, and the second part of the duodenum is a secondarily retroperitoneal organ. Also, remember that the anterior and posterior superior pancreaticoduodenal arteries are branches of the gastroduodenal artery, which receives blood from the celiac trunk. The anterior and posterior inferior pancreaticoduodenal arteries receive blood from the superior mesenteric artery.

The inferior mesenteric artery is often occluded by atherosclerosis without symptoms; its normal area of distribution therefore must be supplied by collateral blood flow between which arteries? A. Ileocolic and right colic B. Left and middle colic C. Left colic and sigmoidal D. Right and middle colic E. Sigmoidal and superior rectal

B. Left and middle colic To answer this question, you need to identify which branches represent an anastomosis between the superior mesenteric artery and the inferior mesenteric artery. So, you want to find the answer choice listing the most distal branch of the superior mesenteric artery and the most proximal branch of the inferior mesenteric artery. And, those branches are the middle colic (from the SMA) and the left colic (from the IMA). The ileocolic, right colic, and middle colic arteries are branches of the superior mesenteric artery; the left colic, sigmoidal, and superior rectal arteries are branches of the inferior mesenteric artery.

A patient presented with a swollen spleen, which protruded medially toward the umbilicus in the abdomen. A vertical and downward expansion of the spleen was resisted by the: A. Tail of the pancreas B. Left colic flexure C. Left kidney D. Left renal artery E. Stomach

B. Left colic flexure The left colic flexure, also called the splenic flexure, is the point where the colon takes a sharp downward turn. This flexure is the point where the transverse colon ends and the descending colon begins. It is located immediately inferior to the spleen, so an enlarged spleen must move medially to avoid this colic flexure. The stomach lies medial to the speen, and the tail of the pancreas inserts into the hilum of the spleen. These organs would not prevent the spleen from descending inferiorly. The kidney and left renal artery are retroperitoneal organs; they would not obstruct movement of the spleen.

A patient was diagnosed with bleeding ulcer of the lesser curvature of the stomach. Which artery is most likely involved? A. Gastroduodenal B. Left gastric C. Left gastro-omental (epiploic) D. Right gastro-omental (epiploic) E. Short gastrics

B. Left gastric The left gastric artery is the artery that supplies the lesser curvature of the stomach (along with the right gastric artery.) These two arteries would be most likely to cause bleeding at the lesser curvature of the stomach. The left gastric is one of the three arteries that comes off of the celiac trunk. The left and right gastro-omental arteries are the two arteries that supply the greater curvature of the stomach. The gastroduodenal artery is a branch off the common hepatic artery that supplies the duodenum, head of the pancreas, and the greater curvature of the stomach. The short gastric arteries are 4 or 5 small arteries from the splenic artery that supply the fundus of the stomach.

An obstetrician decides to do a Caesarean section on a 25-year-old pregnant woman. A transverse suprapubic incision is chosen for that purpose. All of the following abdominal wall layers will be encountered during the incision EXCEPT the: A. Anterior rectus sheath B. Posterior rectus sheath C. Rectus abdominis muscle D. Skin and subcutaneous tissue E. Transversalis fascia, extraperitoneal fat, and peritoneum

B. Posterior rectus sheath Remember - the transverse suprapubic incision (also called the Pfannenstiel incision) is made below the arcuate line. So, there is no longer a posterior layer of the rectus sheath, and the inner surface of the rectus abdominis is lined only with transversalis fascia. When making this incision, the abdominal wall layers are incised as follows: skin, superficial fascia (fatty and membranous), deep fascia, anterior rectus sheath, rectus abdominis muscle, transversalis fascia, extraperitoneal connective tissue, and peritoneum.

While performing emergency surgery to control hemorrhage brought on by arterial erosion caused by a duodenal ulcer, surgeons ligated the badly damaged gastroduodenal artery near its origin, which affected all of its branches as well. Assuming "average anatomy", in which of the following arteries would blood now flow in retrograde fashion (backwards) from collateral sources? A. Left hepatic B. Right gastroepiploic C. Short gastric D. Left gastric E. Omental branches

B. Right gastroepiploic If the gastroduodenal artery and its branches were ligated, blood would flow in a retrograde direction from the left gastroepiploic artery, which is a branch of the splenic artery, to the right gastroepiploic artery, a ligated branch of the gastroduodenal artery. This flow from the left to right gastroepiploic artery would allow blood to reach the entire greater curvature of the stomach. Remember--there are many anastomoses around the stomach that will allow this organ to receive blood even if one branch is ligated. The left hepatic artery is a branch of the proper hepatic artery; it supplies blood to the left and quadrate lobes of the liver, as well as part of the caudate lobe. The short gastric arteries are branches of the splenic artery which supply the fundus of the stomach. The left gastric artery is a branch of the celiac trunk which supplies the left portion of the lesser curvature. Omental branches are branches of the left and right gastroomental arteries which supply the greater omentum.

Visceral pain is often referred to a site on the body wall (where the patient "feels" it) that is innervated by the same spinal cord segment that innervates the visceral organ involved. Pain of appendicitis is often first felt around the umbilicus, indicating that the appendix receives its sympathetic (and thus visceral afferents) from which spinal cord segment? A. T9 B. T10 C. T11 D. T12 E. L1

B. T10 Sensation from around the umbilicus is mediated by T10. This is an important landmark to remember!

A 40 year-old male with a long history of duodenal ulcer problems was brought in for emergency surgery to control severe hemorrhage into the peritoneal cavity. The surgeons found that erosion by the ulcer of a vessel passing behind the first part of the duodenum was the source of the hemorrhage. Which of the following vessels passes behind the first part of the duodenum and would need to be clamped off to control the bleeding? A. coronary vein B. gastroduodenal artery C. inferior pancreatoduodenal arcade D. proper hepatic artery E. splenic vein

B. gastroduodenal artery The gastroduodenal artery lies behind the superior part of the duodenum. It has three branches: the posterior superior pancreaticoduodenal artery, the anterior superior pancreaticoduodenal artery, and the right gastroomental artery. The other vessels are not near the superior duodenum. The coronary vein is made of the right and left gastric veins and located in the lesser curvature of the stomach. The inferior pancreatoduodenal arcade is found in the inferior part of the head of the pancreas. It supplies the pancreas and duodenum. It is near the horizontal (3rd) part of the duodenum, not the superior part. The proper hepatic artery is a branch of the common hepatic artery which delivers oxygenated blood to the liver. Finally, the splenic vein comes from the spleen--it joins the superior mesenteric vein to form the portal vein.

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: A. aorta B. inferior vena cava C. portal vein D. right renal artery E. superior mesenteric vein

B. inferior vena cava 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)

Meckel's diverticulum: A. is an abnormal persistance of the urachus B. is a site of ectopic pancreatic tissue C. is caused by a failure of the midgut loop to return to the abdominal cavity D. is an abnormal connection of the midgut to the duodenum E. is associated with polyhydramnios

B. is a site of ectopic pancreatic tissue Meckel's diverticulum is an out-pouching of the small bowel that is present in 2% of the people and usually occurs about 2 feet before the junction with the cecum. It can be lined by the mucosa of the stomach and ulcerate. Or, it can be lined with ectopic pancreatic tissue. An abnormal persistence of the urachus is called a urachal fistula. Since the urachus is attached to the bladder, this can be detected if yellow fluid (urine) is seen coming from the umbilicus of a newborn. A failure of the midgut loop to return to the abdominal cavity is called an omphalocele. In this instance, the midgut remains in the body stalk, where it had left the gut to rotate. Polyhydramnios is an excess production of amniotic fluid , often caused by anencephaly or an esophageal fistula. The other conditions will be covered more in embryology - for now, focus on Meckel's diverticulum.

During preparations to remove the left kidney from a 28-year-old female patient, the surgeon asked an observing medical student where best to ligate the renal vein. Upon hearing the reply: "as close to the inferior vena cava as possible, leaving just enough stump to ensure tight closure," the surgeon's eyebrow shot up. "Do you mean to say you're willing to compromise the venous drainage of the other structures that drain into the renal vein?" By this he meant all of the following except: A. diaphragm B. pancreas C. ovary D. suprarenal gland

B. pancreas Since the inferior vena cava is on the right side of the abdomen, structures on the left will need to have longer venous channels to connect to the IVC and drain into it. Consequently, some of the paired retroperitoneal structures that drain directly into the IVC on the right side cannot do that on the left. Instead, they must drain into the renal vein, which crosses over the aorta and under the superior mesenteric artery to connect to the inferior vena cava. The left inferior phrenic vein, left suprarenal vein, and left ovarian/testicular vein all drain into the left renal vein (although their analogs on the right side drain directly into the IVC). If the left renal vein was ligated as it crosses the aorta, blood from the left diaphragm, ovary, and suprarenal gland would have to drain posteriorly - into the left second lumbar vein, which connects to the posterior aspect of the left renal vein. The pancreas drains into the portal venous system and would not be affected by this ligation.

A 57-year-old male complains of intense chest pain, but tests rule out any cardiac pathology. It was determined that the patient suffers from an esophageal (hiatal) hernia in which the stomach herniates through an enlarged esophageal hiatus. Muscle fibers from which of the following parts of the diaphragm would border directly on this hernia? A. left crus B. right crus C. central tendon D. costal fibers E. sternal fibers

B. right crus The right crus is the part of the diaphragm that takes origin from L1-L3. It splits to enclose the esophagus. So, in the case of an esophageal hernia, the herniating stomach would be entirely surrounded by the fibers of the right crus. The left crus is the part of diaphragm that takes origin from L1 and L2. It is smaller and shorter than the right crus, and it intermingles with the right crus around the aortic hiatus. It does not contribute to the esophageal hiatus. The central tendon is the tendon in the middle of the diaphragm where all the fibers of the diaphragm attach. It provides an opening for the inferior vena cava. Finally, sternal and costal fibers refer to muscle fibers in the diaphragm that take origin from the xyphoid process or the ribcage. This could not refer to the right crus, since it originates on the lumbar vertebrae.

A patient was admitted with symptoms of an upper bowel obstruction. Upon CT examination, it was found that the third (transverse) portion of the duodenum was compressed by a large vessel causing the obstruction. The vessel involved is most likely to be the: A. inferior mesenteric artery B. superior mesenteric artery C. inferior mesenteric vein D. portal vein E. splenic vein

B. superior mesenteric artery The superior mesenteric artery crosses over the third part of the duodenum, and the aorta is posterior to the third part of the duodenum. If something causes these vessels to become enlarged, they can crush the duodenum, and food won't be able to pass through the duodenum. This is often called the "nutcracker effect," and it is only seen in the third part of the duodenum. Take a look at Netter Plate 292 for an illustration of the third part of the duodenum lying between these important vessels. You should know what structures are involved in the "nutcracker effect" and how they are causing an upper bowel obstruction!

Which of the following is NOT in contact with the spleen? A. Colon B. Diaphragm C. Duodenum D. Pancreas E. Stomach

C. Duodenum The duodenum is not in contact with the spleen. The inferior portion of the spleen contacts the left colic flexure. The superior portion of the spleen contacts the diaphragm--the spleen is convexly curved to fit the concavity of the diaphragm. The tail of the pancreas inserts into the hilum of the spleen. The stomach contacts the anteriomedial portion of the spleen. You should really know what organs contact the spleen and where these organs contact the spleen!

A 45-year-old man had developed a direct inguinal hernia several months after having an emergency appendectomy. The examining doctor linked the cause of hernia to accidental nerve injury that happened during appendectomy and weakened the falx inguinalis. Which nerve had been injured? A. Femoral branch of the genitofemoral B. Genital branch of the genitofemoral C. Ilioinguinal D. Subcostal E. Ventral primary ramus of T10

C. Ilioinguinal A direct inguinal hernia is caused by a weakness in the abdominal muscles which prevents a patient from contracting these muscles strongly. If this patient can't contract his muscles, he can't pull the falx inguinalis down to cover the thin area of weak fascia on the posterior wall of the inguinal canal. The ilioinguinal nerve is important for innervating the muscles of the lower abdominal wall. So, if this nerve was damaged during the appendectomy, the man might not be able to contract his abdominal muscles and pull the falx inguinalis over the weak fascia. This could have led him to develop the direct inguinal hernia. The genitofemoral nerve innervates the cremaster muscle. An injury to this muscle would lead to an inability to elevate the testes, but it would not compromise the strength of the abdominal wall. The subcostal nerve and the ventral primary ramus of T10 innervate muscles, skin & fascia of the abdominal wall above the inguinal region. The anterior cutaneous branch of T10 reaches the umbilicus specifically.

Upon endoscopic examination of a 65-year-old man who had a history of a chronic duodenal ulcer, it was found that the ulcer had been eroding the posterior wall of the first part of the duodenum. If erosion perforates the wall, the gastric expellant of high acidity would endanger the structures in its vicinity. Which is least likely to be endangered? A. Common bile duct B. Gastroduodenal artery C. Main pancreatic duct D. Portal vein

C. Main pancreatic duct The pancreas is inferior to the superior portion of the duodenum, and the main pancreatic duct is found deep within the pancreas. It is not likely that this structure would be damaged by the duodenal ulcer. The portal vein, gastroduodenal artery, and the common bile duct all pass immediately deep to the first part of the duodenum. (The portal vein and common bile duct are associated with the proper hepatic artery, forming the portal triad.) These structures would all be at risk from the ulcer. See Netter Plate 279 for a picture illustrating this relationship.

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? A. Deep inguinal ring B. Lateral inguinal fossa C. Medial inguinal fossa D. Superficial inguinal ring E. Supravesical fossa

C. Medial inguinal fossa 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.

Occlusion of the inferior mesenteric artery is seldom symptomatic because its territory may be supplied by branches of the: A. Gastroduodenal B. Ileocolic C. Middle colic D. Right colic E. Splenic

C. Middle colic The middle colic artery is the branch from the superior mesenteric artery that supplies the transverse colon. This is the most distal part of the colon that receives blood from the SMA. Branches from the middle colic go to the marginal artery, which would be able to supply the descending colon, sigmoid colon, and rectum if the inferior mesenteric artery was occluded. The ileocolic and right colic arteries are also branches of the SMA supplying the colon (and contributing to the marginal artery), but the middle colic, which serves a more distal part of the colon, is a better answer. The gastroduodenal artery is a branch off of the common hepatic artery which supplies parts of the duodenum, pancreas, and stomach. The splenic artery is one of the three branches of the celiac trunk. It supplies the spleen, pancreas, and curvature of the stomach.

During an emergency splenectomy, the surgeon accidentally tore the gastrosplenic ligament and its contents. The artery (ies) likely to be damaged in this event is (are) the: A. Left gastric B. Splenic C. Short gastric D. Middle colic E. Caudal pancreatic

C. Short gastric The short gastric arteries branch from the splenic artery near the hilum of the spleen. They travel in the gastrosplenic ligament to supply the fundus of the stomach. So, these arteries might be damaged if the gastrosplenic ligament was disrupted. The left gastric artery is a branch of the celiac trunk which supplies the left half of the lesser curvature. The splenic artery travels deep to the stomach to reach the hilum of the spleen. Although its branches travel in the gastrosplenic ligament, the splenic artery passes within the splenorenal ligament to reach the splenic hilum, and it would not be damaged by an incision in gastrosplenic ligament. The middle colic artery is a branch of the superior mesenteric artery which supplies the transverse colon. The caudal pancreatic artery is a branch of the splenic artery which supplies the tail of the pancreas. It, along with most of the pancreas, is retroperitoneal.

A patient presents with a hernia that is palpable at the superficial inguinal ring. Is this an indirect inguinal hernia? A. Yes B. No C. There is insufficient evidence to tell

C. There is insufficient evidence to tell You can't tell if a hernia is direct or indirect just by palpating it! Although it is more common for indirect hernias to pass through the superficial inguinal ring while direct hernias usually stay in the inguinal canal, it is possible that a direct hernia could protrude through the superficial ring and even enter the scrotum.

In order to do a vagotomy (section of vagal nerve trunks) to reduce the secretion of acid by cells of the stomach mucosa in patients with peptic ulcers, one needs to cut the gastric branches and retain vagal innervation to other abdominal organs. Where would a surgeon look for these branches in relation to the stomach? A. along the gastroepiploic vessels B. along the greater curvature C. along the lesser curvature D. in the base of the omental apron E. in the gastrocolic ligament

C. along the lesser curvature The vagal branches to the stomach are found on the lesser curvature. The anterior vagal branches are derived from the left vagal nerve and the posterior vagal branches are derived from the right vagal nerve. This makes sense, since during the rotation of the gut, the left side of the stomach rotated to become the ventral aspect of the stomach. Vagotomies are done to reduce the acid secretion of the stomach, since the vagus sends one of the signals that stimulates the parietal cells of the stomach to release HCl.

The division between the true right and left lobes (internal lobes) of the liver may be visualized on the outside of the liver as a plane passing through the: A. gallbladder fossa and round ligament of liver B. falciform ligament and ligamentum venosum C. gallbladder fossa and inferior vena cava D. falciform ligament and right hepatic vein E. gallbladder fossa and right triangular ligament

C. gallbladder fossa and inferior vena cava This question is asking you to identify the structures that make the line that separates the true/functional lobes of the liver. The concept of functional lobes contrasts with traditional anatomical terminology, which separated the liver into the left, right, quadrate and caudate lobes. These traditional lobes were based on anatomical appearance, while the functional lobes are based on the distribution of the portal vein, hepatic arteries, and hepatic bile ducts. The functional lobes of the liver are separated into a right and left lobe by the gallbladder fossa and the inferior vena cava. So, the old "right lobe" corresponds to the functional right lobe, while the caudate, quadrate, and left lobes under anatomical terminology are lumped together as one big left lobe.

Which of the following veins does not run a course parallel to the artery of the same name? A. superior epigastric B. superficial circumflex iliac C. inferior mesenteric D. superior rectal E. ileocolic

C. inferior mesenteric The inferior mesenteric vein and inferior mesenteric artery do not run in tandem. The inferior mesenteric vein is part of the portal venous system--it drains into the splenic vein which drains into the hepatic portal vein. The inferior mesenteric artery is a branch off the descending aorta at the level of the L3 vertebral body. However, the inferior mesenteric artery and vein supply/drain the same region: the descending and sigmoid colon and the rectum. The superior epigastric vessels run together and are the continuation of the internal thoracic artery and vein. The superficial circumflex iliac vessels run together in the superficial fat of the abdominal wall. The superior rectal vessels are the terminal ends of the inferior mesenteric vessels, found on the superior surface of the rectum. The ileocolic artery and vein are branches off the superior mesenteric vessels. They are both running in the mesentery, supplying/draining the cecum, appendix, and terminal portion of the ileum.

The celiac plexus of nerves may contain fibers derived from all of the following sources except: A. posterior vagal trunk B. greater thoracic splanchnic nerve C. lesser thoracic splanchnic nerve D. lumbar splanchnic nerves

C. lesser thoracic splanchnic nerve The celiac plexus of nerves contains fibers from the greater thoracic splanchnic nerves, which are synapsing in the celiac ganglia. This plexus also contains vagal fibers. Even though the vagus does not synapse in the celiac ganglia, it passes through the ganglia and contributes to the celiac plexus. This allows the vagal fibers to travel on arteries to reach their eventual targets. The lesser thoracic splanchnic nerves are not part of the celiac ganglia--these nerves synapse in the aorticorenal ganglia and contribute to the renal plexus. The first lumbar splanchnic nerve may occasionally contribute to the celiac plexus.

A medical student was asked by her preceptor to palpate the margin of the superficial inguinal ring of a healthy male patient. After passing her finger down the edge of the medial crus of the superficial inguinal ring, she felt a bony protuberance deep to the lateral edge of the spermatic cord, which she correctly identified as the: A. pecten pubis B. pubic symphysis C. pubic tubercle D. iliopubic eminence E. iliopectineal line

C. pubic tubercle The pubic tubercle is a bony process that would be felt lateral to the edge of the spermatic cord at the superficial inguinal ring. (This is really the only answer choice that could feel like a bony prominence when palpated.)The pubic tubercle serves as the point of attachment for the inguinal ligament, which makes up the floor of the inguinal canal. The pubic pecten is the ridge on the superior surface of the superior pubic ramus. This is the place where you find the pectineal ligament, a thickening of fascia on the pecten of the pubis. The pectineal ligament is a good place to put sutures when doing surgery. The pubic symphysis is the joint between the two pubic bones. The iliopubic eminence is a bony process on the pubis found near its articulation with the ilium. The iliopectineal line is a line formed by the arcuate line of the ilium and the pectineal line of the pubis. This line forms a plane that marks the transition between the abdominal and pelvic cavity.

The usual location for an appendectomy incision is the: A. left lower quadrant B. left upper quadrant C. right lower quadrant D. right upper quadrant

C. right lower quadrant Since the appendix is located in the right lower quadrant, you would probably want to make your incision there to remove it! The appendix is the terminal portion of the cecum which has a small, dead-end lumen. It is located just behind the cecum in the right internal iliac fossa. Where are incisions made for other procedures? For a cholecystectomy (gall bladder removal), there is an incision in the right upper quadrant. (Or, this surgery can be performed laproscopically.) For a caesarian, a transverse suprapubic incision (also called a Pfannenstiel incision) is used. A midline incision, through the linea alba, may be used to repair an aortic aneurysm.

The inferior border of the rectus sheath posteriorly is called the: A. Falx inguinalis B. Inguinal ligament C. Internal inguinal ring D. Arcuate line E. Linea alba

D. Arcuate line The rectus sheath is a tough, tendinous sheath over the rectus abdominis muscle. It covers the entire anterior surface of the rectus abdominis. However, on the posterior side of the muscle, the sheath is incomplete-- it ends inferiorly at the arcuate line. Below the arcuate line, the rectus abdominis is covered by transversalis fascia, not the rectus sheath! The linea alba is also related to the rectus abdominis--it is a ligament that runs down the middle of the abdomen, bisecting the rectus abdominis. It is made by the intermingling of the aponeuroses of the external oblique, internal oblique, and transversus abdominis. It's a good place to make a vertical incision. All of the other answer choices are related to the inguinal canal. The falx inguinalis (sometimes called the inguinal falx or conjoint tendon), is the inferomedial attachment of transversus abdominis with some fibers of internal abdominal oblique--it contributes to the posterior wall of the inguinal canal. The inguinal ligament is the ligament that connects the anterior superior iliac spine with the pubic tubercle--it makes the floor of the inguinal canal. The internal (deep) inguinal ring is the entrance to the inguinal canal, where the transversalis fascia pouches out and creates an opening through which structures can leave the abdominal cavity.

Which statement regarding the suprarenal glands is correct? A. Its entire arterial supply is directly from the abdominal aorta. B. Veins from both glands drain directly into the inferior vena cava. C. The glands are localized in the pararenal space. D. Cells that secrete epinephrine and norepinephrine are innervated by preganglionic fibers from the greater thoracic splanchnic nerve.

D. Cells that secrete epinephrine and norepinephrine are innervated by preganglionic fibers from the greater thoracic splanchnic nerve. The suprarenal medulla is directly innervated by preganglionic sympathetic fibers from the greater thoracic splanchnic nerve. These preganglionic fibers synapse on the cells of the adrenal medulla, causing the cells in the adrenal medulla to release norepinephrine and/or epinephrine. The preganglionic fibers can synapse on these cells of the adrenal medulla because they are modified nervous tissue. The epinephrine and norepinepherine enters the blood stream to cause a systemic response. The superior suprarenal arteries branch from the inferior phrenic, the middle suprarenal artery is a direct branch of the abdominal aorta, and the inferior suprarenal arteries are branches of the renal artery. Although the vein from the right gland drains into the inferior vena cava, the vein from the left suprarenal gland drains into the left renal vein. Finally, the pararenal space is the space outside the renal fascia, covered with the pararenal fat. The suprarenal gland is covered by the renal fascia, so it's in the perirenal space, not in the pararenal space.

Which is a derivative of the dorsal mesogastrium? A. Falciform ligament B. Hepatoduodenal ligament C. Hepatogastric ligament D. Greater omentum E. Lesser omentum

D. Greater omentum During the development of the gut, there are two mesogastria attaching to the developing stomach: the dorsal mesogastrium and the ventral mesogastrium. Different organs begin to develop in each mesogastrium--the spleen and pancreas develop in the dorsal mesogastrium and the liver develops in the ventral mesogastrium. So, the structures involving the spleen and the posterior part of the developing stomach (which becomes the greater curvature) are derived from the dorsal mesogastrium. These include: the greater omentum (gastrophrenic ligament, gastrosplenic ligament, gastrocolic ligament) and splenorenal ligament. The structures involved with the liver and its attachment to the stomach wall form the ventral mesogastrium. These include the lesser omentum (hepatogastric ligament, hepatoduodenal ligament) and the ligaments of the liver (falciform ligament, coronary ligaments, right and left triangular ligaments). Of the answer choices, only the greater omentum is part of the dorsal mesogastrium.

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 A. Celiac branch of the anterior vagal trunk B. Celiac branch of the posterior vagal trunk C. Greater splanchnic branch to the right suprarenal gland D. Hepatic branch of the anterior vagal trunk E. Hepatic branch of the posterior vagal trunk

D. Hepatic branch of the anterior vagal trunk 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.

A patient was diagnosed with pancreatitis due to a reflux of bile into the pancreatic duct caused by a gallstone. The stone is likely to be lodged at the: A. Common bile duct B. Common hepatic duct C. Cystic duct D. Hepatopancreatic ampulla

D. Hepatopancreatic ampulla The hepatopancreatic ampulla is the very short segment of duct which represents the joining of the common bile duct and the main pancreatic duct. Once these two ducts form the hepatopancreatic ampulla in the wall of the duodenum, the bile and pancreatic enzymes are emptied into the second portion of the duodenum, through the major duodenal papilla. If a gallstone was stuck in the hepatopancreatic ampulla, bile could back up and flow backwards into the main pancreatic duct. If a stone was lodged in the cystic duct, common hepatic duct, or common bile duct, bile would never even reach the pancreas. See Netter Plate 276 for an illustration.

An elderly patient with a large indirect inguinal hernia came to your clinic complaining of pain in the scrotum. You conclude that the hernial sac is compressing the following nerve: A. Femoral branch of the genitofemoral B. Femoral C. Iliohypogastric D. Ilioinguinal E. Subcostal

D. Ilioinguinal The ilioinguinal nerve runs in the inguinal canal, so this nerve could easily be compressed by an inguinal hernia. The ilioinguinal nerve also gives off the anterior scrotal nerve, which is the nerve responsible for sensory innervation to the anterior scrotum. The location of this hernia and the scrotal pain both fit with an injury to the ilioinguinal nerve. The femoral branch of the genitofemoral provides sensory innervation to the upper medial thigh. The femoral nerve innervates the anterior compartment of the thigh, and has some cutaneous sensory branches to the thigh. The iliohypogastric nerve innervates the skin of the lower abdominal wall, upper hip, and upper thigh. Finally, the subcostal nerve is the ventral primary ramus of T12, which innervates the skin of the anterolateral abdominal wall.

A surgical maneuver which takes advantage of the avascular plane of fusion fascia can be applied to mobilize all of the organs below, except the: A. Ascending colon B. Descending colon C. Duodenum D. Kidney E. Pancreas

D. Kidney Fusion fascia forms when an organ becomes secondarily retroperitoneal. Secondarily retroperitoneal organs started out in a mesentery, but then got pushed against the posterior body wall during development. So, the peritoneal covering on the face of these organs which was pushed against the posterior body wall became fusion fascia--a relatively avascular plane of fascia that holds these organs to the posterior body wall. The ascending colon, descending colon, duodenum, and pancreas are all secondarily retroperitoneal organs which are attached by fusion fascia. The kidney is an entirely retroperitoneal organ that was never associated with a mesentery during development. So, it is not attached to the body wall by fusion fascia.

A pediatrician has diagnosed a newborn baby of having right-sided cryptorchidism (undescended testis). The testis may have been trapped in any site EXCEPT: A. At the deep inguinal ring B. Just outside the superficial inguinal ring C. Pelvic brim D. Perineum E. Somewhere in the inguinal canal

D. Perineum To understand this question, you need to understand the descent of the testes. The testes begin as retroperitoneal structures in the posterior abdominal wall. They are attached to the anterolateral abdominal wall by the gubernaculum. The gubernaculum "pulls" the testes through the deep inguinal ring, inguinal canal, superficial inguinal ring, and over the pelvic brim. The gubernaculum is preceded by the processus vaginalis, which is derived from the peritoneum anterior to the testes. The processus vaginalis "pushes" the muscle and fascia layers, which will eventually make up the canal and spermatic cord, into the scrotum. After the testes are in position in the scrotum, the gubernaculum persists as the scrotal ligament, while part of the processus vaginalis remains as a bursa-like sac called the tunica vaginalis testis. So, the testes could get caught in the deep inguinal ring, inguinal canal, at the superficial inguinal ring, or at the pelvic brim. The testes are never in the perineum, and they wouldn't get stuck there.

You are observing an operation to remove the left suprarenal gland. To expose the gland the surgeon mobilizes the descending colon by cutting along its lateral attachment to the body wall and dissecting medialward in the fusion fascia behind it. Suddenly the operative field is filled with blood. The surgeon realizes he has failed to cut a mesenteric attachment between the left colic flexure and another organ. As a result of the traction, the surface of the organ tore. Which organ was injured? A. Duodenum B. Kidney C. Liver D. Spleen E. Suprarenal gland

D. Spleen The spleen is a peritonealized organ that is attached to the left colic flexure. It could tear if there was too much traction while pulling the descending colon away from the body wall. Another clue in this scenario that points to a ruptured spleen is the large amount of blood that fills the operative field. The spleen is covered by a very thin capsule, and it has a soft and pulpy parenchyma. So, when it is ruptured, the spleen bleeds profusely. The duodenum and liver are not associated with the left colic flexure. The kidney and suprarenal glands are retroperitoneal organs that are not associated with any mesenteric attachment.

Superior mesenteric A twenty-year-old woman was broad-sided on the driver side by an SUV and was taken to the hospital emergency room. Examination showed low blood pressure and tenderness on the left mid-axillary line. Also, a large swelling was felt protruding downward and medially below the left costal margin. X-rays revealed that her 9th and 10th ribs were fractured near their angles on the left side. The abdominal organ most likely to be injured by the fracture is: A. Descending colon B. Left kidney C. Pancreas D. Spleen E. Stomach

D. Spleen The spleen is usually well protected by the 9th through 12th ribs on the left side. But, if one or more of these ribs gets fractured, the spleen is the first organ to be ruptured. The spleen can also be damaged if there is blunt trauma to the abdomen or a sudden increase in intraabdominal pressure. This patient has several symptoms of a ruptured spleen--she has tenderness on the left posterior axillary line and hypotension. (Because of its spongy parenchyma and thin capsule, a ruptured spleen will bleed profusely and a patient may become hypotensive.) The stomach, splenic flexure of the colon, tail of the pancreas, left kidney, and suprarenal gland are in the same quadrant of the abdomen, and they are also at risk for injury. But, you should remember that the spleen is at greatest risk because of its close relationship with the 9th through 12th ribs.

During emergency surgery, it was found that a chronic gastric ulcer had perforated the posterior wall of the stomach and eroded a large artery running immediately posterior to the stomach. The artery is the: A. Gastroduodenal B. Common hepatic C. Left gastroepiploic D. Splenic E. Superior mesenteric

D. Splenic Netter Plate 288 will help you to understand this answer. The splenic artery is a branch of the celiac trunk. It passes deep to the stomach and sends branches to the pancreas before reaching the spleen. If the posterior wall of the stomach eroded, gastric juices could damage the splenic artery. The gastroduodenal artery lies behind the first portion of the duodenum. An ulcer in this portion of the duodenum might jeopardize the gastroduodenal artery. The common hepatic artery is a branch of the celiac trunk which runs superior to the lesser curvature of the stomach. The left gastroepiploic artery runs on the left side of the greater curvature of the stomach. Finally, the superior mesenteric artery arises from the aorta at the L1 level, posterior to the pancreas. It crosses over the third portion of the duodenum.

The inferior mesenteric vein usually joins which vein? A. Inferior vena cava B. Left renal C. Portal D. Splenic E. Superior mesenteric

D. Splenic The inferior mesenteric vein usually empties into the splenic vein. The splenic vein and the superior mesenteric vein then unite to form the portal vein. Look at Netter Plate 290 for a picture of this. Remember--the inferior vena cava and left renal vein are caval veins--they are not involved in draining the gut.

A 58-year-old patient was diagnosed with a severe case of portal hypertension due to alcoholic cirrhosis of the liver. It was determined that a bypass between the vessels of the portal and caval systems was necessary. The plan most likely to be successful is: A. Coronary vein to right gastro-omental vein B. Left colic vein to sigmoidal vein C. Inferior mesenteric vein to splenic vein D. Splenic vein to left renal vein E. Superior rectal vein to inferior rectal vein

D. Splenic vein to left renal vein The splenic vein is a major vein of the portal system, while the left renal vein is a major vein of the caval system. These veins are large, so a bypass between them could be useful for relieving the portal hypertension. The coronary vein, right gastro-omental vein, left colic vein, sigmoidal vein, inferior mesenteric vein, and splenic vein are all part of the portal system. Any bypasses among these veins will not relieve the portal hypertension. The superior and inferior rectal veins already form a portal-caval anastomosis; surgery would not be needed to connect these two venous channels. However, if too much blood tries to flow through this anastomosis, hemorrhoids will develop. These veins are not large enough to help relieve severe portal hypertension.

A surgeon needs to construct a bypass between the veins of the portal and caval systems to circumvent insufficient drainage through the natural portacaval anastomoses. Which plan is likely to be successful? A. Coronary vein to right gastroepiploic vein B. Inferior mesenteric vein to splenic vein C. Left colic vein to middle colic vein D. Splenic vein to left renal vein E. Superior mesenteric vein to splenic vein

D. Splenic vein to left renal vein The splenic vein is a major vein of the portal system, while the left renal vein is a major vein of the caval system. These veins are large, so a bypass between them could be useful for relieving the portal hypertension. The coronary vein, right gastroepiploic vein, inferior mesenteric vein, splenic vein, left colic vein, middle colic vein, and superior mesenteric vein are all part of the portal system. Any bypasses among these veins will not relieve the portal hypertension.

Orally ingested contrast medium opacifies all of the following structures except the: A. colon B. duodenum C. esophagus D. gall bladder E. stomach

D. gall bladder The orally ingested contrast medium would coat all the structures of the gut tube, including the esophagus, stomach, duodenum, and colon. The medium should go anywhere that ingested food might go in the GI tract. The gallbladder, however, is not a part of the passageway for food - it concentrates and secretes stored bile. So, the gall bladder would not be filled with contrast.

During a laparoscopic examination of the deep surface of the lower anterior abdominal wall (using a lighted scope on a thin tube inserted through the wall), the attending physician noted something of interest and asked the young resident to look at the medial inguinal fossa. To do so, the young doctor would have to look at the area between the: A. inferior epigastric artery and urachus B. medial umbilical ligament and urachus C. inferior epigastric artery and lateral umbilical fold D. medial umbilical ligament and inferior epigastric artery E. median umbilical ligament and medial umbilical ligament

D. medial umbilical ligament and inferior epigastric artery Remember, the medial umbilical fold is made by the medial umbilical ligament (the obliterated portion of the umbilical artery), while the lateral umbilical fold is a fold of peritoneum over the inferior epigastric vessels. The median umibilical fold is a midline structure made by the median umbilical ligament (obliterated urachus). The medial inguinal fossa is the space on the inner abdominal wall between the medial umbilical fold and the lateral umbilical fold. This is the place in the abdominal wall where there is an area of weak fascia called the inguinal triangle--direct inguinal hernias can break through this space. The lateral inguinal fossa is a space lateral to the lateral umbilical fold--indirect inguinal hernias push through the deep inguinal ring in this space.

During a full workup on a 2-month-old infant with a history of intermittent gastrointestinal pain and vomiting, physicians discovered that the cause was lack of emptying of the stomach. They immediately suspected that the cause was a spasmodic contraction of which of the following parts of the stomach? A. cardiac notch B. fundus C. lesser curvature D. pylorus E. rugae

D. pylorus Pyloric stenosis is a congenital disorder in which the pylorus is thickened causing obstruction of the gastric outlet to the duodenum. This problem is more commonly seen in males. Symptoms like projectile vomiting appear several weeks after birth.

Sympathetic fibers in the greater splanchnic nerve arise from neuron cell bodies found in the: A. brainstem B. celiac ganglion C. chain ganglion D. spinal cord E. superior mesenteric ganglion

D. spinal cord The sympathetic fibers in the greater thoracic splanchnic nerve are preganglionic sympathetic fibers that have left the sympathetic chain and are going to synapse in abdominal ganglia. These preganglionic sympathetic fibers originate in the lateral horn of the spinal cord grey matter. The celiac ganglia and the superior mesenteric ganglia are the two ganglia where the fibers from the greater thoracic splanchnic nerve can go to synapse. Finally, remember that these fibers did not originate in the chain ganglia--the fibers from there are the postganglionic sympathetic fibers.

While performing a splenectomy (removal of the spleen) following an automobile accident, the surgeons were especially attentive to locate and preserve the tail of the pancreas which is closely associated with the spleen. This they found in the: A. gastrocolic ligament B. gastrosplenic ligament C. phrenicocolic ligament D. splenorenal ligament E. transverse mesocolon

D. splenorenal ligament The splenorenal ligament is the peritoneal structure that connects the spleen to the posterior abdominal wall over the left kidney. It also contains the tail of the pancreas. The gastrocolic ligament connects the greater curvature of the stomach with the transverse colon. The gastrosplenic ligament connects the greater curvature of the stomach with the hilum of the spleen. The phrenicolic ligament connects the splenic flexure of the colon to the diaphragm. Finally, the transverse mesocolon connects the transverse colon to the posterior abdominal wall.

A man is moving into a new house and during the process lifts a large chest of drawers. As he lifts he feels a severe pain in the lower right quadrant of his abdomen. He finds that he can no longer lift without pain and the next day goes to see his physician. Surgery is indicated and during the surgery the surgeon opens the inguinal region and finds a hernial sac with a small knuckle of intestine projecting through the abdominal wall just above the inguinal ligament and lateral to the inferior epigastric vessels. The hernia was diagnosed as: A. A congenital inguinal hernia B. A direct inguinal hernia C. A femoral hernia D. An incisional hernia E. An indirect inguinal hernia

E. An indirect inguinal hernia An indirect inguinal hernia leaves the abdominal cavity lateral to the inferior epigastric vessels and enters the inguinal canal through the deep inguinal ring. Commonly, these hernias traverse the entire inguinal canal, leave the canal through the superficial inguinal ring, and enter the scrotum. The indirect inguinal hernias are the most common type of hernia, and are often caused by heavy lifting. Direct inguinal hernias leave the abdominal cavity medial to the inferior epigastric vessels, through the weak fascia. These usually do not traverse the entire inguinal canal, and they rarely enter the scrotum. Direct inguinal hernias may be caused by a weakness of abdominal musculature. Congenital inguinal hernias are indirect hernias that occur due to the persistence of the processus vaginalis, an embryonic structure that is a diverticulum of the peritoneal cavity extending into the labial or scrotal folds. A femoral hernia is caused by abdominal viscera pushing through the femoral ring into the femoral canal. An incisional hernia occurs after surgery, when omentum or an organ protrudes through a surgical incision due to poor healing.

As the bowel is exposed, the surgeon says in amazement, "This is a loop of large bowel!" Which characteristic(s) would identify it specifically as large bowel? A. A serosa B. Circular folds C. Epiploic appendages D. Tenia E. C and D

E. C and D There are three features that distinguish the large intestine from the small intestines. The large intestine does not have a continuous longitudinal muscle layer--instead, it has three strips of longitudinal muscle known as teniae coli. The large intestine is covered with omental appendages, which are fat-filled pendants of peritoneum on the surface of the large intestine. Finally, the large intestine is folded into sacculations known as haustra, which form where the longitudinal muscle layer of the wall of the large intestine is deficient. Serosa is a general term for the outermost coat or serous layer of a visceral structure that lies in the body cavities of the abdomen or thorax. Circular folds are found in the small intestine, and semilunar (sometimes called semicircular) folds are found in the large intestine. These folds are actually much more prominent in the small intestine; in the large intestine, there are mostly semicircular folds which do not continue around the entire intestine.

Which ligament is a derivative of the dorsal mesogastrium? A. Coronary B. Falciform C. Hepatoduodenal D. Hepatogastric E. Gastrocolic

E. Gastrocolic Structures involving the spleen and posterior part of the developing stomach (which becomes the greater curvature) are derived from the dorsal mesogastrium. This includes the gastrocolic ligament (including the omental apron), gastrophrenic ligament, gastrosplenic ligament, and the splenorenal ligament. The liver develops in the ventral mesogastrium. This means that any structures involving the liver and its attachment to the lesser curvature of the stomach or the body wall will be derivatives of the ventral mesogastrium. This includes the coronary ligament, the falciform ligament, the left and right triangular ligaments, the hepatogastric ligament, and the hepatoduodenal ligament.

A 15-year-old boy was admitted to the emergency room for having large bowel obstruction resulting from a left-sided indirect inguinal hernia. The most likely intestinal segment involved in this obstruction is the: A. ascending colon B. cecum C. descending colon D. rectum E. sigmoid colon

E. sigmoid colon The sigmoid colon is the most likely intestinal segment to be involved in a left-sided indirect inguinal hernia. Although the descending colon is also on the left side of the abdomen, it is a bit superior to be herniating through the deep inguinal ring. The ascending colon and cecum are on the right side of the abdomen, so they would not be involved with a left sided hernia. Finally, the rectum is a structure in the pelvis; it is too inferior to enter the deep inguinal ring and cause an indirect inguinal hernia.

The normal pattern of venous and lymphatic drainage of the superficial tissues of the anterior abdominal wall is arranged around a horizontal plane. Above that plane, drainage is in a cranial direction; below the plane drainage is in a caudal direction. This reference plane corresponds to: A. Transpyloric plane B. Level of anterior superior iliac spines C. Transtubercular line D. Level of arcuate line E. Level of umbilicus

E. Level of umbilicus The umbilicus is an important landmark for venous and lymphatic drainage of the abdominal wall. Above the umbilicus, lymphatics drain into the axillary lymph nodes and the venous blood drains into the superior epigastric vein, which drains to the internal thoracic vein. Below the umbilicus, lymphatics drain into the superficial inguinal lymph nodes, while venous blood drains into the inferior epigastric vein and the external iliac vein.

Surgical approaches to the abdomen sometimes necessitate a midline incision between the two rectus sheaths, i.e., through the: A. Linea aspera B. Arcuate line C. Semilunar line D. Iliopectineal line E. Linea alba

E. Linea alba The linea alba is an aponeurotic band on the midline of the anterior abdominal wall, which extends from the xiphoid process to the pubic symphysis. It is formed by the combined abdominal muscle aponeuroses. Because there are no major arteries or nerves running in the linea alba, it provides a useful site for a midline incision in the abdomen. The linea aspera is a vertical ridge on posterior surface of the femur. The arcuate line is the point at which the posterior lamina of the rectus sheath ends, and transversalis fascia lines the inner surface of rectus abdominis. The semilunar line is the lateral margin of the rectus abdominus, formed by the fused aponeuroses of the abdominal wall muscles. The iliopectineal line is a line on the pelvic bones, formed by the arcuate line of the ilium and the pectineal line of the pubis. (Note--the arcuate line of the ilium is totally different than the arcuate line of the rectus sheath!) This line is important because it marks the boundary between the abdominal cavity and the pelvic cavity.

The anastomotic artery running along the border of the large intestine is called the: A. Arcade B. Arteriae rectae C. Coronary D. Ileocolic E. Marginal

E. Marginal The marginal artery is an important anastomosis for the large intestine. It runs around the border of the large intestine, and it is formed by the anastomosis of branches of the ileocolic artery, right colic artery, middle colic artery, left colic artery, and sigmoid artery. If a small artery becomes occluded, these branches allow blood to reach all segments of the colon. Arcades are anastomotic loops between arteries that provide alternative pathways for blood flow. These arcades are more prominent in the small intestine than the large intestine. Arteriae rectae (straight arteries) are the small branches that run from the marginal artery to reach the colon. The ileocolic artery is the branch of the superior mesenteric artery that supplies the cecum, appendix, and terminal portion of the ileum. The coronary arteries supply blood to the heart, but just to confuse things, the gastric veins are refered to as coronary veins, because they crown the lesser curvature of the stomach.

In a female with an indirect inguinal hernia, the herniated mass lies along side of which structure as it traverses the inguinal canal? A. Iliohypogastric nerve B. Inferior epigastric artery C. Ovarian artery and vein D. Pectineal ligament E. Round ligament of the uterus

E. Round ligament of the uterus In females, the round ligament of the uterus is the main structure traversing the inguinal canal. In males, the most important structure in the inguinal canal is the spermatic cord. The iliohypogastric nerve innervates the abdominal wall. It runs between the transversus abdominis and internal oblique muscles, then pierces the internal oblique at the anterior superior iliac spine to run between the internal and external obliques. The inferior epigastric artery lies between the peritoneum and the transversus abdominis, creating the lateral umbilical fold. The ovarian artery and vein are branches from the descending aorta and inferior vena cava which supply the ovary in the pelvis. The pectineal ligament is a thick layer of fascia over the pectineal line of the pubis. Although the pectineal ligament helps define the boundaries of the inguinal canal, you can't really say that the pectineal ligament traverses the canal. That's why the round ligament is the best answer.

Which structure passes through the deep inguinal ring? A. Iliohypogastric nerve B. Ilioinguinal nerve C. Inferior epigastric artery D. Medial umbilical ligament E. Round ligament of the uterus

E. Round ligament of the uterus The round ligament of the uterus passes through the deep inguinal ring and runs through the inguinal canal. It is a derivative of the gubernaculum, a structure which pulled the gonads into place during embryonic development. In males, the scrotal ligament is what remains from the gubernaculum. Also keep in mind that, in males, the spermatic cord passes through the deep inguinal ring. Of the other answer choices, the ilioinguinal nerve is the only other one that courses through the inguinal canal. Remember--it leaves through the superficial ring and gives off the anterior labial or scrotal branch as a cutaneous continuation. However, the ilioinguinal nerve does not pass through the deep ring - it enters the inguinal canal on the side. The iliohypogastric nerves run between the internal oblique and transversus abdominis in the abdominal wall, piercing the internal oblique at the anterior superior iliac spine to travel deep to just the external oblique. The inferior epigastric artery runs between the transversus abdominis and the peritoneum, forming the lateral umbilical fold. The medial umbilical ligament is the obliterated umbilical artery--it lies within the medial umbilical fold of peritoneum.

During the surgical repair of a hiatal hernia, the celiac branch of the posterior vagal trunk was severed accidentally. The damage to this nerve would affect the muscular movements, as well as some secretory activities, of the gastrointestinal tract (GI). Which segment is least likely to be affected by the nerve damage? A. Ascending colon B. Cecum C. Jejunum D. Ileum E. Sigmoid colon

E. Sigmoid colon The vagus nerve supplies parasympathetic fibers to all of the abdominal organs which receive blood from the celiac trunk or superior mesenteric artery. This means that the vagus supplies parasympathetics to the entire GI tract, up to the last part of the transverse colon. The end of transverse colon and all GI structures distal to that point receive parasympathetic innervation from the pelvic splanchnic nerves and blood from the inferior mesenteric artery. So, the ascending colon, cecum, jejunum, and ileum would all be affected by damage to the vagus nerve. The sigmoid colon, which receives parasympathetic innervation from the pelvic splanchnics, would not be affected.

The fundus of the stomach receives its arterial supply from the: A. Common hepatic B. Inferior phrenic C. Left gastroepiploic D. Right gastric E. Splenic

E. Splenic As it enters the hilum of the spleen, the splenic artery gives off short gastric arteries which supply blood to the fundus of the stomach. These short gastric arteries travel in the gastrosplenic ligament to reach the fundus. The common hepatic artery does not directly supply the stomach--it gives off the gastroduodenal artery, which supplies the right portion of the greater curvature of the stomach with the right gastro-omental artery. The inferior phrenic artery is a branch of the aorta which supplies blood to the diaphragm. The left gastro-omental artery is a branch of the splenic artery which supplies the left half of the greater curvature. The right gastric artery is a branch of the proper hepatic artery which supplies the right half of the lesser curvature. See Netter Plate 290 to get a good picture of these arteries and their areas of distribution.

The artery of the midgut is the: A. Celiac trunk B. Inferior mesenteric C. Proper hepatic D. Splenic E. Superior mesenteric

E. Superior mesenteric The superior mesenteric artery is the artery of the midgut. The celiac trunk is the artery of the foregut, and the inferior mesenteric arery is the artery of the hindgut. The splenic artery is a branch of the celiac artery, and the proper hepatic artery is a branch of the common hepatic artery, which is a branch of the celiac artery.

An ulcer near the pyloroduodenal junction perforated and eroded a large artery immediately posterior to the duodenum. The ligation of the eroded vessel at its origin would LEAST affect the arterial supply to the: A. First part of the duodenum B. Second part of the duodenum C. Greater curvature of the stomach D. Head of the pancreas E. Tail of the pancreas

E. Tail of the pancreas The gastroduodenal artery is the artery that has ruptured. This artery gives off the anterior and posterior superior pancreatoduodenal arteries, which supply the first and second parts of the duodenum, as well as the head of the pancreas. The gastroduodenal artery also gives off the right gastroomental artery, which supplies the right half of the greater curvature of the stomach. In contrast, the tail of the pancreas is supplied by the caudal pancreatic artery, which is a branch of the splenic artery. It would not be affected by damage to the gastroduodenal artery.

A surgeon performing an appendectomy was unable to identify the base of the appendix due to massive adhesions in the peritoneal cavity. Eventually she identified the cecum and was able to localize the base of the appendix. What anatomical structure(s) on the cecum would she have used to find the base of the appendix? A. Omental appendages B. Haustra coli C. Ileal orifice D. Semilunar folds E. Teniae coli

E. Teniae coli The teniae coli are three bands of longitudinal muscle on the surface of the large intestine. The large intestine does not have a continuous layer of longitudinal muscle--instead, it has teniae coli. These three bands meet at the appendix, which projects from the dependent portion of the cecum. The omental appendages are fatty appendages which are unique to the large intestine. These are all over the large intestine and are not specifically associated with the appendix. The haustra are multiple pouches in the wall of the large intestine, which form where the longitudinal muscle layer of the wall of the large intestine is deficient. Remember--the teniae coli, omental appendages, and the haustra are the three distinctive features of the large intestine! The ileal orifice is the space where the ileum open into the cecum--it is surrounded by the ileocecal valve. The semilunar folds are the folds found along the lining of the large intestine.

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? A. Camper's and Scarpa's fascias B. External abdominal oblique and internal abdominal oblique muscles C. Internal abdominal oblique and transversus abdominis muscles D. Skin and deep fascia of the abdominal wall E. Tranversus abdominis muscle and peritoneum

E. Tranversus abdominis muscle and peritoneum 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.

While performing a routine digital examination of the inguinal region in a healthy teen-aged male, the physician felt a walnut-sized lump protruding from the superficial inguinal ring. She correctly concluded that it was : A. definitely an indirect inguinal hernia B. possibly an unusual femoral hernia C. definitely a direct inguinal hernia D. possibly an enlarged superficial inguinal lymph node E. either a direct or an indirect inguinal hernia

E. either a direct or an indirect inguinal hernia You can't tell if an inguinal hernia is direct or indirect just by palpating it! Although indirect hernias are the ones that usually come out of the superficial inguinal ring and enter the scrotum, direct inguinal hernias might do this too! As for the other answers... a femoral hernia goes through the femoral ring into the femoral canal--it has nothing to do with the superficial inguinal ring. A superficial inguinal lymph node lies in the superficial fascia, parallel to the inguinal ligament. It would feel more superficial and should not be mistaken for a hernia protruding through the inguinal ring.

During development of the gut: A. the sigmoid colon is retroperitoneal B. the inferior mesenteric artery is the axis for rotation of the midgut loop C. the stomach rotates around its longitudinal axis causing the ventral border to become the greater curvature D. the liver is non-functional E. none of the above

E. none of the above None of the statements about development are correct. During development, structures that are peritonealized become retroperitoneal when they are pressed against the body wall and stay there. Structures do not start out retroperitoneal and become peritonealized later. Since the sigmoid colon is peritonealized in the adult, it has not and will not ever be retroperitoneal. The superior mesenteric artery is the axis for rotation of the midgut loop. This should make sense, since the SMA supplies the midgut. When the stomach rotates, the ventral border becomes the lesser curvature. Finally, the liver is functional in the fetus - it is an early site for the formation of erythrocytes.

Which of the following structures does not lie at least partially in the retroperitoneum? A. adrenal gland B. duodenum C. kidney D. pancreas E. spleen

E. spleen The spleen is the only organ listed which is covered entirely by visceral peritoneum. About the other organs... The kidney and suprarenal glands are retroperitoneal organs. This is different than the secondarily retroperitoneal organs that started out in a mesentery and then got pushed against the posterior wall. The kidneys and the suprarenal glands began developing in the retroperitoneum and stayed there. The duodenum and pancreas are partially peritonealized and partially retroperitoneal. The first two centimeters of the superior duodenum is peritonealized, but the rest of the duodenum, until the duodenojejunal junction, is retroperitoneal. For the most part, the pancreas is secondarily retroperitoneal, although the tail of the pancreas is peritonealized, lying within the splenorenal ligament.

After successfully performing two adrenalectomies (removal of the adrenal gland), the surgical resident was disappointed to learn that he would be merely assisting at the next one. The chief of surgery told him: "I'm doing this one, since the one on the right side may be a little too difficult for you." The difficulty he envisioned stems from the fact that the right suprarenal gland is partly overlain anteriorly by the: A. aorta B. inferior vena cava C. left hepatic vein D. right crus of the diaphragm E. right renal artery

Remember that the inferior vena cava is a little off center, on the right side of the abdomen. This means that structures on the right might be closely associated with this vessel, while structures on the left will need to have longer venous channels to connect with the IVC and drain into it. In the case of the suprarenal glands, you can see that the IVC is laying over the right suprarenal gland and is very far from the left gland. (This means that the right gland is draining directly into the inferior vena cava, while the left gland is draining into the renal vein.) As far as the other structures in the question go... The aorta lies fairly evenly between the suprarenal glands--it is not overlying either gland. The left hepatic vein, which drains blood from the liver to the inferior vena cava, is superior to the kidneys and not really involved with this area. The right crus of the diaphram is a set of fibers that splits to make the esophageal hiatus, and the right renal artery is a branch off the aorta to the kidney which enters the kidney below the level of the suprarenal gland.

The spleen normally does not descend below the costal margin. However, it pushes downward and medially when pathologically enlarged. What structure limits the straight vertical downward movement? A. Left colic flexure B. Left suprarenal gland C. Ligament of Treitz D. Pancreas E. Stomach

The left colic flexure, also called the splenic flexure, is the point where the colon takes a sharp downward turn. This flexure is the point where the transverse colon ends and the descending colon begins. It is located immediately inferior to the spleen, so an enlarged spleen must move medially to avoid this colic flexure. The left suprarenal gland is a retroperitoneal structure which sits superior to the kidney. The suspensory muscle of the duodenum or ligament of Treitz is a thin sheet of muscle derived from the right crus of the diaphragm--it suspends the fourth part of the duodenum from the posterior abdominal wall. Both the pancreas and stomach lie medial to the speen. These organs would not prevent the spleen from descending inferiorly.

The superficial inguinal ring is an opening in which structure? A. External abdominal oblique aponeurosis B. Falx inguinalis C. Internal abdominal oblique muscle D. Scarpa's fascia E. Transversalis fascia

The superficial inguinal ring is a slit-like opening between the diagonal fibers of the external abdominal oblique. It is bounded by the medial and lateral crus, and it forms the exit of the inguinal canal. The falx inguinalis is composed of arching fibers of the internal abdominal oblique and the transversus abdominis. It forms the roof of the inguial canal, and the posterior wall medially where it inserts as the conjoint tendon (onto the pubic crest and medial part of the pectineal ligament. Scarpa's fascia is the membranous layer of subcutaneous fascia. Finally, transversalis fascia is found laterally on the posterior wall of the inguinal canal, forming the area of weak fascia in that wall.