Block 6 Anat Abdomen BRS W Expl Prt 2

1. A 54-year-old man with a long history of alcohol abuse presents to the emergency department with rapidly increasing abdominal distention most likely resulting from an alteration in portal systemic blood flow. Which of the following characteristics is associated with the portal vein or the portal venous system?

Lower blood pressure than in the inferior vena cava

Least risk of venous varices because of portal hypertension

Distention of the portal vein resulting from its numerous valves

Caput medusae and hemorrhoids caused by portal hypertension

Less blood flow than in the hepatic artery

Portal hypertension can cause esophageal varices, caput medusa, and hemorrhoids. The portal vein has higher pressure than systemic veins; the vein and its tributaries have no valves, or, if present, they are insignificant. In addition, the portal vein carries two to three times as much blood as the hepatic artery.

Explanation

Portal hypertension can cause esophageal varices, caput medusa, and hemorrhoids. The portal vein has higher pressure than systemic veins; the vein and its tributaries have no valves, or, if present, they are insignificant. In addition, the portal vein carries two to three times as much blood as the hepatic artery.

2. An elderly man with prostatic hypertrophy returns to his urologist with another case of epididymitis. An acute infection involving the dartos muscle layer of the scrotum most likely leads to an enlargement of which of the following lymph nodes?

Preaortic nodes

Lumbar nodes

External iliac nodes

Superficial inguinal nodes

Common iliac nodes

The superficial inguinal lymph nodes receive lymph from the scrotum, penis, buttocks, and lower part of the anal canal, and their efferent vessels enter primarily to the external
iliac nodes and ultimately to the lumbar (aortic) nodes. The deep inguinal nodes receive lymph from the testis and upper parts of the vagina and anal canal, and their efferent vessels enter the external
iliac nodes.

Explanation

The superficial inguinal lymph nodes receive lymph from the scrotum, penis, buttocks, and lower part of the anal canal, and their efferent vessels enter primarily to the external
iliac nodes and ultimately to the lumbar (aortic) nodes. The deep inguinal nodes receive lymph from the testis and upper parts of the vagina and anal canal, and their efferent vessels enter the external
iliac nodes.

3. A physical fitness trainer for a young Hollywood movie star explains the reasons for 100 stomach crunches a day. The young star, a medical student before "hitting it big" reaffirms to his trainer that the lateral margin of the rectus abdominis, the muscle responsible for a washboard stomach, defines which one of the following structures?

Linea alba

Linea semilunaris

Linea semicircularis

Transversalis fascia

Falx inguinalis

The linea semilunaris is a curved line along the lateral border of the rectus abdominis. The linea alba is a tendinous median raphe between the two rectus abdominis muscles. The linea semicircularis is an arcuate line of the rectus sheath, which is the lower limit of the posterior layer of the rectus sheath. The falx inguinalis (conjoint tendon) is formed by aponeuroses of the internal oblique and transverse abdominal muscles (otherwise known as the transversalis fascia).

Explanation

The linea semilunaris is a curved line along the lateral border of the rectus abdominis. The linea alba is a tendinous median raphe between the two rectus abdominis muscles. The linea semicircularis is an arcuate line of the rectus sheath, which is the lower limit of the posterior layer of the rectus sheath. The falx inguinalis (conjoint tendon) is formed by aponeuroses of the internal oblique and transverse abdominal muscles (otherwise known as the transversalis fascia).

4. While examining radiographs and angiograms of a 52-year-old patient, a physician is trying to distinguish the jejunum from the ileum. He has observed that the jejunum has:

Fewer plicae circulares

Fewer mesenteric arterial arcades

Less digestion and absorption of nutrients

Shorter vasa recta

More fat in its mesentery

The jejunum has fewer mesenteric arterial arcades but longer vasa recta than the ileum. The plicae circulares (circular folds) are tall and closely packed in the jejunum and are
low and sparse in the ileum, and the lower part of the ileum has no plicae circulares. More digestion and absorption of nutrients occurs in the jejunum than in the ileum, and less fat is found in the mesentery of the jejunum.

Explanation

The jejunum has fewer mesenteric arterial arcades but longer vasa recta than the ileum. The plicae circulares (circular folds) are tall and closely packed in the jejunum and are
low and sparse in the ileum, and the lower part of the ileum has no plicae circulares. More digestion and absorption of nutrients occurs in the jejunum than in the ileum, and less fat is found in the mesentery of the jejunum.

5. Which structure is hematopoietic in early life and later destroys worn out red blood cells?

A

B

C

D

E

The spleen lies in the left hypochondriac region, is hematopoietic in early life, and later functions in worn-out red blood cell destruction. It filters blood, stores red blood
cells, and produces lymphocytes and antibodies.

Explanation

The spleen lies in the left hypochondriac region, is hematopoietic in early life, and later functions in worn-out red blood cell destruction. It filters blood, stores red blood
cells, and produces lymphocytes and antibodies.

6. A 43-year-old woman is admitted to a hospital because of deep abdominal pain in her epigastric region. On examination, it is observed that a retroperitoneal infection erodes an artery that runs along the superior border of the pancreas. Which of the following arteries is likely injured?

Right gastric artery

Left gastroepiploic artery

Splenic artery

Gastroduodcnal artery

Dorsal pancreatic artery

http://upload.wikimedia.org/wikipedia/commons/3/3b/Gray533.pngThe splenic artery arises from the celiac trunk, runs along the superior border of the pancreas, and enters the spleen through the lienorenal ligament and the hilus of the spleen.
The right gastric artery runs along the lesser curvature of the stomach, and
The left gastroepiploic artery runs along the greater curvature of the stomach.
The gastroduodenal artery runs behind the first part of the duodenum.
The dorsal pancreatic artery descends behind the neck of the pancreas and divides into right and left branches to supply the pancreas.

Explanation

http://upload.wikimedia.org/wikipedia/commons/3/3b/Gray533.pngThe splenic artery arises from the celiac trunk, runs along the superior border of the pancreas, and enters the spleen through the lienorenal ligament and the hilus of the spleen.
The right gastric artery runs along the lesser curvature of the stomach, and
The left gastroepiploic artery runs along the greater curvature of the stomach.
The gastroduodenal artery runs behind the first part of the duodenum.
The dorsal pancreatic artery descends behind the neck of the pancreas and divides into right and left branches to supply the pancreas.

7. A patient with cryptogenic cirrhosis is scheduled for liver transplant surgery. During the operation rounds, the transplant physician explains to his residents that one of the reasons a surgeon must pay close attention to the anatomic location of the liver is that this organ:

Receives blood only from the hepatic arteries

Manufactures red blood cells in an adult

Drains bile from the quadrate lobe into the right hepatic duct

Drains venous blood into the hepatic veins

Functions to concentrate and store bile

. The liver receives blood from the hepatic artery and portal vein and drains its venous blood into the hepatic veins. The liver manufactures RBC’s in the fetus. The liver plays important roles in bile production and secretion. The quadrate lobe drains bile into the left hepatic duct, not the right hepatic duct, whereas the caudate lobe drains bile into the right and left hepatic ducts. The gallbladder functions to concentrate and store bile.

Explanation

. The liver receives blood from the hepatic artery and portal vein and drains its venous blood into the hepatic veins. The liver manufactures RBC’s in the fetus. The liver plays important roles in bile production and secretion. The quadrate lobe drains bile into the left hepatic duct, not the right hepatic duct, whereas the caudate lobe drains bile into the right and left hepatic ducts. The gallbladder functions to concentrate and store bile.

8. A 26-year-old patient is admitted to a local hospital with a retroperitoneal infection. Which of the following arteries is most likely to be infected?

Left gastric artery

Proper hepatic artery

Middle colic artery

Sigmoid arteries

Dorsal pancreatic artery

The pancreas is a retroperitoneal organ, except for a small portion of its tail. The dorsal pancreatic artery would be the infected artery because it arises from the splenic artery and runs ret roperitoneally along the superior border of the pancreas behind the peritoneum. The other arteries run within layers of the peritoneum. The left gastric arteries run within the lesser omentum; the proper hepatic artery runs within the free margin of the lesser omentum; the middle colic artery runs within the transverse mesocolon; the sigmoid arteries run within the sigmoid mesocolon.

Explanation

The pancreas is a retroperitoneal organ, except for a small portion of its tail. The dorsal pancreatic artery would be the infected artery because it arises from the splenic artery and runs ret roperitoneally along the superior border of the pancreas behind the peritoneum. The other arteries run within layers of the peritoneum. The left gastric arteries run within the lesser omentum; the proper hepatic artery runs within the free margin of the lesser omentum; the middle colic artery runs within the transverse mesocolon; the sigmoid arteries run within the sigmoid mesocolon.

9. A 41-year-old woman is brought to the ER by her family because of acute onset of right upper quadrant pain, nausea, and vomiting. For this case, it important to remember that the bile duct:

Drains bile into the second part of the duodenum

Can be blocked by cancer in the body of the pancreas

Joins the main pancreatic duct, which carries hormones

Is formed by union of the right and left hepatic duct

Lies posterior to the portal vein in the right free edge of the lesser omentum

The bile duct is formed by union of the common hepatic and cystic ducts, lies lateral to the proper hepatic artery and anterior to the portal vein in the right free margin of the lesser omentum, traverses the head of the pancreas, and drains bile into the second part of the duodenum at the greater papilla. The endocrine part of the pancreas secretes the hormones insulin and glucagon, which are transported through the bloodstream. The main pancreatic duct carries pancreatic juice containing enzymes secreted from the exocrine part of the pancreas.

Explanation

The bile duct is formed by union of the common hepatic and cystic ducts, lies lateral to the proper hepatic artery and anterior to the portal vein in the right free margin of the lesser omentum, traverses the head of the pancreas, and drains bile into the second part of the duodenum at the greater papilla. The endocrine part of the pancreas secretes the hormones insulin and glucagon, which are transported through the bloodstream. The main pancreatic duct carries pancreatic juice containing enzymes secreted from the exocrine part of the pancreas.

10. A patient with diverticulosis of the colon presents for follow-up to his primary care physician with ongoing complaints of left lower quadrant pain and occasionally bloody stools. His physician begins workup with appropriating test by recalling that the sigmoid colon:

Is drained by systemic veins

Is a retroperitoneal organ

Receives parasympathetic fibers from the vagus nerve

Receives its blood from the superior mesenteric artery

Has teniae coli and epiploic appendages

. The sigmoid colon has teniae coli and epiploic appendages. The sigmoid colon receives blood from the inferior mesenteric artery, drains its venous blood through the portal tributaries, has its own mesentery (sigmoid mesocolon; therefore, is not a retroperitoneal organ), and receives parasympathetic preganglionic fibers from the pelvic splanchnic nerve.

Explanation

. The sigmoid colon has teniae coli and epiploic appendages. The sigmoid colon receives blood from the inferior mesenteric artery, drains its venous blood through the portal tributaries, has its own mesentery (sigmoid mesocolon; therefore, is not a retroperitoneal organ), and receives parasympathetic preganglionic fibers from the pelvic splanchnic nerve.

11. A 57-year-old patient has a tumor in the body of the pancreas that obstructs the inferior mesenteric vein just before joining the splenic vein. Which of the following veins is most likely to be enlarged?

Middle colic vein

Left gastroepiploic vein

Inferior pancreaticoduodenal vein

Ileocolic vein

Left colic vein

The left colic vein is a tributary of the inferior mesenteric vein. The middle colic, inferior pancreaticoduodenal, and ileocolic veins drain into the superior mesenteric vein. The lett gastroepiploic vein empties into the splenic vein.

Explanation

The left colic vein is a tributary of the inferior mesenteric vein. The middle colic, inferior pancreaticoduodenal, and ileocolic veins drain into the superior mesenteric vein. The lett gastroepiploic vein empties into the splenic vein.

12. A 53-year-old woman with known kidney disease presents to a hospital because her pain has become increasingly more severe. A physician performing kidney surgery must remember that:

The left kidney lies a bit lower than the right one

The peri-renal fat lies external to the renal fascia

The renal fascia does not surround the suprarenal gland

The left renal vein runs anterior to both the aorta and the left renal artery

The right renal artery is shorter than the left one

The left renal vein runs anterior to both the aorta and the left renal artery. The renal fascia lies external to the perirenal fat and internal to the pararenal fat, and it also surrounds the suprarenal gland. The right renal artery runs behind the inferior vena cava and is longer than the left renal artery. Because of the large size of the right lobe of the liver, the right kidney lies a little lower than the left.

Explanation

The left renal vein runs anterior to both the aorta and the left renal artery. The renal fascia lies external to the perirenal fat and internal to the pararenal fat, and it also surrounds the suprarenal gland. The right renal artery runs behind the inferior vena cava and is longer than the left renal artery. Because of the large size of the right lobe of the liver, the right kidney lies a little lower than the left.

13. A 58-y/o man is admitted to a hospital with severe abdominal pain, nausea, and vomiting resulting in dehydration. Emergency computed tomography (CT) scan reveals a tumor located between the celiac trunk and the superior mesenteric artery. Which of the following structures is likely compressed by this tumor?

Fundus of the stomach

Neck of the pancreas

Transverse colon

Hepatopancreatic ampulla

Duodenojejunal junction

http://upload.wikimedia.org/wikipedia/commons/3/3b/Gray533.pngThe pyloric canal and the neck of the pancreas are situated anterior to the abdominal aorta between the origin of the celiac trunk and the superior mesenteric artery. The transverse colon passes anterior to the superior mesenteric artery and the third part of the duodenum. The other structures are not located in front of the aorta.

Explanation

http://upload.wikimedia.org/wikipedia/commons/3/3b/Gray533.pngThe pyloric canal and the neck of the pancreas are situated anterior to the abdominal aorta between the origin of the celiac trunk and the superior mesenteric artery. The transverse colon passes anterior to the superior mesenteric artery and the third part of the duodenum. The other structures are not located in front of the aorta.

14. A 67-year-old woman with a long history of liver cirrhosis was seen in the emergency department. In this patient with portal hypertension, which of the following veins is most likely to be dilated?

Right colic vein

Inferior epigastric vein

Inferior phrenic vein

Suprarenal vein

Ovarian vein

The right colic vein belongs to the portal venous system and empties into the superior mesenteric vein, which joins the splenic vein to form the portal vein. The inferior
epigastric, inferior phrenic, suprarenal, and ovarian veins belong to the systemic (or caval) venous system and drain directly or indirectly into the inferior vena Cava.

Explanation

The right colic vein belongs to the portal venous system and empties into the superior mesenteric vein, which joins the splenic vein to form the portal vein. The inferior
epigastric, inferior phrenic, suprarenal, and ovarian veins belong to the systemic (or caval) venous system and drain directly or indirectly into the inferior vena Cava.

15. A pediatric surgeon has resected a structure that is a fibrous remnant of embryonic or fetal artery in a 5-year-old child. Which of the following structures is most likely to be divided?

Lateral umbilical fold

Medial umbilical told

Median umbilical fold

Ligamentum teres hepatis

Ligamentum venosum

The mediaL umbilical fold or ligament contains a fibrous remnant of the umbilical artery.
The mediaN umbilical fold contains a fibrous remnant of the urachus and allantois.
The lateral umbilical fold (ligament) contains the inferior epigastric artery and vein, which are adult blood vessels.
The ligamentum venosum contains a fibrous remnant of the ductus venosus and
The ligamentum teres hepatic contains a fibrous remnant of the left umbilical vein.

Explanation

The mediaL umbilical fold or ligament contains a fibrous remnant of the umbilical artery.
The mediaN umbilical fold contains a fibrous remnant of the urachus and allantois.
The lateral umbilical fold (ligament) contains the inferior epigastric artery and vein, which are adult blood vessels.
The ligamentum venosum contains a fibrous remnant of the ductus venosus and
The ligamentum teres hepatic contains a fibrous remnant of the left umbilical vein.

16. During surgical treatment of portal hypertension of a 59-year-old man with liver cirrhosis, a surgeon inadvertently lacerates the dilated paraumbilical veins. The veins must be repaired to allow collateral flow. Which of the following ligaments is most likely severed?

Lienorenal ligament

Lienogastric ligament

Gastrophrenic ligament

Ligamentum teres hepatis

Ligamentum venosum

The paraumbilical veins and the ligamentum teres hepatis are contained in the free margin of the falciform ligament.
The lienorenal ligament contains the splenic vessels and a small portion of the tail of the pancreas.
The lienogastric ligament contains the left gastroepiploic and short gastric vessels.
The gastrophrenic ligament contains no named structures.
The hepatoduodenal ligament, a part of the lesser omentum, contains the bile duct, proper hepatic artery, and portal vein in its free margin.

Explanation

The paraumbilical veins and the ligamentum teres hepatis are contained in the free margin of the falciform ligament.
The lienorenal ligament contains the splenic vessels and a small portion of the tail of the pancreas.
The lienogastric ligament contains the left gastroepiploic and short gastric vessels.
The gastrophrenic ligament contains no named structures.
The hepatoduodenal ligament, a part of the lesser omentum, contains the bile duct, proper hepatic artery, and portal vein in its free margin.

17. A 9-year-old girl has crashed into her neighbor's brick fence while riding her bike and is brought to the emergency department with a great deal of abdominal pain. Her radiogram and angiogram show laceration of the superior mesenteric artery immediately distal to the origin of the middle colic artery. If collateral circulation is discounted, which of the following organs may become ischemic?

Descending colon

Duodenum

Pancreas

Ascending colon

Transverse colon

http://upload.wikimedia.org/wikipedia/commons/6/62/Gray534.pngThe right colic and ileocolic arteries arise from the superior mesenteric artery distal to the origin of the middle colic artery. The right colic artery may arise from the ileocolic artery and supplies the ascending colon. The duodenum and pancreas receive blood from the inferior pancreaticoduodenal artery and superior pancreaticoduodenal. The pancreas is also supplied by the splenic artery of the celiac trunk. The transverse colon receives blood from the middle colic artery. The descending colon is supplied by the left colic artery, which is a branch of the inferior mesenteric artery.

Explanation

http://upload.wikimedia.org/wikipedia/commons/6/62/Gray534.pngThe right colic and ileocolic arteries arise from the superior mesenteric artery distal to the origin of the middle colic artery. The right colic artery may arise from the ileocolic artery and supplies the ascending colon. The duodenum and pancreas receive blood from the inferior pancreaticoduodenal artery and superior pancreaticoduodenal. The pancreas is also supplied by the splenic artery of the celiac trunk. The transverse colon receives blood from the middle colic artery. The descending colon is supplied by the left colic artery, which is a branch of the inferior mesenteric artery.

18. A 19-year-old young woman with a long history of irritable bowel syndrome presents for the possibility of surgical resection of the gastrointestinal (GI) tract where the vagal parasympathetic innervation terminates. Which of the following sites is most appropriate for surgical resection?

Duodenojejunal junction

Ileocecal junction

Right colic flexure

Left colic flexure

Anorectal junction

The vagus nerve supplies parasympathetic nerve fibers to the gastrointestinal (GI) tract and terminates approximately at the left colic flexure (junction of the transverse colon and the descending colon). The duodenojejunal junction, ileocecal junction, and right colic flexure are supplied by the vagus nerve. The descending colon, sigmoid colon, rectum, anal canal, and anorectal junction are supplied by the pelvic splanchnic nerve for parasympathetic innervation.

Explanation

The vagus nerve supplies parasympathetic nerve fibers to the gastrointestinal (GI) tract and terminates approximately at the left colic flexure (junction of the transverse colon and the descending colon). The duodenojejunal junction, ileocecal junction, and right colic flexure are supplied by the vagus nerve. The descending colon, sigmoid colon, rectum, anal canal, and anorectal junction are supplied by the pelvic splanchnic nerve for parasympathetic innervation.

19. A 58-year-old man is presented with edema of the lower limb and enlarged superficial veins of the abdominal wall. Examination of radiographs and angiograms reveals obstruction of the inferior vena cava just proximal to the origin of the renal vein. This venous blockage may result in dilation of which of the following veins?

Left suprarenal vein

Right inferior phrenic vein

Right hepatic vein

Left gastric vein

Portal vein

The veins distal to obstruction are dilated, but the veins proximal to obstruction are not dilated but have low blood pressure.
The suprarenal vein drains into the left renal vein and thus is dilated because of high pressure.
The right phrenic and right hepatic veins drain into the inferior vena cava above the obstruction.
The left gastric vein joins the portal vein, which enters the liver.

Explanation

The veins distal to obstruction are dilated, but the veins proximal to obstruction are not dilated but have low blood pressure.
The suprarenal vein drains into the left renal vein and thus is dilated because of high pressure.
The right phrenic and right hepatic veins drain into the inferior vena cava above the obstruction.
The left gastric vein joins the portal vein, which enters the liver.

20. An emergent hernia repair is scheduled. As the attending physician is driving to the hospital, the medical student assisting on the case quickly reviews his anatomy atlas and is trying to commit to memory that the internal oblique abdominis muscle contributes to the formation of which of the following structures?

Inguinal ligament

Deep inguinal ring

Falx inguinalis

Internal spermatic fascia

Reflected inguinal ligament

http://upload.wikimedia.org/wikipedia/commons/d/df/Gray398.pngThe falx inguinalis (conjoint tendon) is formed by the aponeuroses of the internal oblique and transverse muscles of the abdomen.

The inguinal ligament is formed by aponeurosis of the external oblique abdominal muscle and the reflected inguinal ligament is formed by certain fibers of the inguinal ligament reflected from the pubic tubercle upward toward the linea alba.

The deep inguinal ring lies in the transversalis fascia, and the internal spermatic fascia is formed by the transversalis fascia.

Explanation

http://upload.wikimedia.org/wikipedia/commons/d/df/Gray398.pngThe falx inguinalis (conjoint tendon) is formed by the aponeuroses of the internal oblique and transverse muscles of the abdomen.

The inguinal ligament is formed by aponeurosis of the external oblique abdominal muscle and the reflected inguinal ligament is formed by certain fibers of the inguinal ligament reflected from the pubic tubercle upward toward the linea alba.

The deep inguinal ring lies in the transversalis fascia, and the internal spermatic fascia is formed by the transversalis fascia.