Grays Flashcards
A 1-year-old female is admitted to the hospital with a palpable mass within one of her labia majora. Radiographic examination reveals that a loop of intestine has herniated into the visibly enlarged labium majus. This condition is due to failure of the processus vaginalis to close off. From which of the following tissue layers is the processus derived? ⃣ A. Parietal peritoneum ⃣ B. Extraperitoneal tissue ⃣ C. Transversalis fascia ⃣ D. Dartos fascia ⃣ E. Internal abdominal oblique aponeurosis
1 A. The processus vaginalis (meaning sheathlike process) is composed of parietal peritoneum that precedes the testis as it “migrates” from a position in the upper lumbar wall to a position outside the abdomen. This process usually obliterates, leaving only a distal portion that surrounds most of the testis as the tunica vaginalis. Whereas these features are typical of development in the male, females also have a processus vaginalis that extends into the labia majus, although congenital inguinal hernias are more common in males than females. The other listed structures are not involved in congenital inguinal hernias. GAS 283; GA 140
A 3-year-old boy is admitted to the hospital with signs of acute renal failure. Radiologic studies reveal that the boy has bilateral masses involving both kidneys. Examination of biopsy material confi rms the diagnosis of Wilms tumor. Which of the following gene mutations is the most common in Wilms tumor? ⃣ A. The gene responsible for WT1 ⃣ B. The gene responsible for HGF ⃣ C. The gene responsible for VEGF ⃣ D. The gene responsible for GDNF ⃣ E. The gene responsible for FGF-2
2 A. Wilms tumor is a kidney malignancy that usually occurs in children. It has recently been shown that it can be caused by mutations in the WT1 gene, behaving according to Knudson’s two-hit model for tumor suppressor genes. GAS 355; GA 147
Fusion of the caudal portions of the kidneys during embryonic development is most likely to result in which of the following congenital conditions? ⃣ A. Bicornuate uterus ⃣ B. Cryptorchidism ⃣ C. Horseshoe kidney ⃣ D. Hypospadias ⃣ E. Renal agenesis
3 C. During development, the kidneys typically “ascend” from a position in the pelvis to a position high on the posterior abdominal wall. Although the kidneys are bilateral structures, occasionally the inferior poles of the two kidneys fuse. When this happens, the “ascent” of the fused kidneys is arrested by the fi rst midline structure they encounter, the inferior mesenteric artery. The incidence of horseshoe kidney is about 0.25% of the population. GAS 355; GA 147
Which of the following congenital malformations will most predictably result in oligohydramnios? ⃣ A. Anencephaly ⃣ B. Pyloric stenosis ⃣ C. Renal agenesis ⃣ D. Tracheoesophageal fi stula ⃣ E. Urethral atresia
C. In normal kidney development the kidneys function during the fetal period with the resulting urine contributing to the fl uid in the amniotic cavity. When the kidneys fail to develop (renal agenesis), this contribution to the fl uid is missing and decreased amniotic fl uid (oligohydramnios) results. GAS 355; GA 147
Failure to urinate during embryonic or fetal life usually causes respiratory diffi culties postnatally. Which of the following relationships best describes this situation? ⃣ A. Oligohydramnios linked with hypoplastic lungs ⃣ B. Polycystic kidneys linked to tracheoesophageal fi stula ⃣ C. Polyhydramnios D. ⃣ Renal agenesis linked to insuffi cient surfactant ⃣ E. Urethral obstruction linked to ectopic viscera
A. There is some evidence that oligohydramnios is linked to hypoplastic lungs. This is apparently not a genetic link but rather related to the importance of adequate amniotic fl uid in normal lung development. GAS 163, 355; GA 76, 147
A 4-year-old male child is admitted to the hospital with severe vomiting. Radiographic examination and history taking reveals that the boy suffers from an annular pancreas. Which of the following structures is most typically obstructed by this condition? ⃣ A. Pylorus of the stomach ⃣ B. First part of the duodenum ⃣ C. Second part of the duodenum ⃣ D. Third part of the duodenum ⃣ E. Jejunum
6 C. In normal pancreatic development a bifi d ventral pancreatic bud rotates around the dorsal side of the gut tube and fuses with the dorsal pancreatic bud. Rarely, a portion of the ventral bud rotates around the ventral side of the gut tube, resulting in an annular pancreas. The portion of the gut tube is the same where the main pancreatic duct enters the second part of the duodenum (along with the common bile duct). The incidence of annular pancreas is about 1 in 7000. GAS 322; GA 167
clinic. Diagnosis reveals that the intermediate portion of the processus vaginalis is not obliterated. Which of the following conditions will most likely result from this? ⃣ A. Hypospadias ⃣ B. Sterility ⃣ C. Congenital hydrocele ⃣ D. Ectopic testis ⃣ E. Epispadias
C. The distal portion of the processus vaginalis contributes to the tunica vaginalis that is related to the testis. If an intermediate portion of the processus vaginalis persists, it often fi lls with fl uid, creating a hydrocele. If the entire processus vaginalis persists, the patient is likely to develop a congenital inguinal hernia. GAS 260; GA 225
Testicles are absent from the scrotum of a 1-yearold male admitted to the pediatric clinic. The pediatrician examined the infant and palpated the testes in the inguinal canal. Which of the following terms is used to describe this condition? ⃣ A. Pseudohermaphroditism ⃣ B. True hermaphroditism ⃣ C. Cryptorchism ⃣ D. Congenital adrenal hyperplasia ⃣ E. Chordee
C. Cryptorchism, often called an undescended testis, is the result of incomplete migration of the gonad from the abdomen to a location in the scrotum where it is exposed to temperatures slightly lower than core body temperature. This is important for spermatogenesis and testicular function. A testis that cannot be surgically relocated into the scrotum is usu- ally removed because it would otherwise be prone to develop testicular cancer.
A 28-year-old woman who is 8 months pregnant goes to the outpatient clinic for her prenatal checkup. Ultrasound examination of the fetus reveals gastroschisis, with herniation of the small bowel into the amniotic cavity. Failure of proper formation of which of the following structure(s) has resulted in this condition? ⃣ A. Head fold ⃣ B. Tail fold ⃣ C. Neural folds ⃣ D. Lateral folds ⃣ E. Amnion
D. The lateral folds are key structures in forming the muscular portion of the anterior abdominal wall. Failure of the lateral folds can cause a minor defect, such as an umbilical hernia, or a major defect, such as gastroschisis. GAS 256, 299; GA 154
Rotation of the stomach during development results in movement of the left vagus nerve from its original position. Through approximately how many degrees of rotation does the nerve move, and what is its fi nal position? ⃣ A. 90 ° to become the anterior vagal trunk ⃣ B. 90 ° to become the posterior vagal trunk ⃣ C. 270 ° to become the anterior vagal trunk ⃣ D. 270 ° to become the posterior vagal trunk ⃣ E. 180 ° to become the right vagal trunk
10 A. Rotation of the gut tube is a major event in the development of the gastrointestinal system. Parts of the tube rotate 270 ° , but the proximal foregut, specifi cally that portion that forms the esophagus, rotates only 90 ° . Looking from below (the standard CT or MRI view), this rotation is counterclockwise. This brings the left vagus nerve onto the anterior surface of the esophagus as it passes through the thorax. GAS 256, 345; GA 190
A newborn baby was diagnosed with eventration of the diaphragm, wherein one half of the diaphragm ascends into the thorax during inspiration, but the other half contracts normally. What is the most likely cause of this condition? ⃣ A. Absence of a pleuropericardial fold ⃣ B. Absence of musculature in one half of the diaphragm ⃣ C. Failure of migration of the diaphragm ⃣ D. Failure of development of the septum transversum ⃣ E. Absence of a pleuroperitoneal fold
11 B. The diaphragm develops from several components. Initially, the septum transversum (which will become the central tendon) forms in the cervical region, gaining innervation from C3, C4, and C5. Later, myoblasts migrate in from the body wall to form the muscular part of the diaphragm, often considered to be two bilateral hemidiaphragms. These muscles are innervated by the phrenic nerves. Eventration of the diaphragm occurs when one muscular hemidiaphragm fails to develop. With positive pressure in the abdominal cavity, and low or negative pressure in the thoracic cavity, abdominal organs are pushed into the thorax. The pleuroperitoneal folds contribute to a portion of the diaphragm posteriorly. GAS 353; GA 67
A 2-day-old newborn male is cyanotic after attempts to swallow milk result in collection of the milk in his mouth. After 2 days he develops pneumonia. A tracheoesophageal fi stula is suspected. Which of the following structures has failed to develop properly? ⃣ A. Esophagus ⃣ B. Trachea ⃣ C. Tongue ⃣ D. Tracheoesophageal septum ⃣ E. Pharynx
2 D. The tracheoesophageal septum is the downgrowth that separates the ventral wall of the foregut (esophagus) from the laryngotracheal tube. The presence of a fi stula would result in passage of fl uid from the esophagus into the trachea and could cause pneumonia. If the esophagus did not develop correctly, as in esophageal atresia, it would end as a blind tube. This kind of defect, although associated with tracheoesophageal fi stula, is not the result of an opening into the trachea, and pneumonia would not result. Abnormal tracheal development can be associated with tracheoesophageal fi stula, therefore, but it is not the direct cause of it. Abnormal tongue development does not result in a tracheoesophageal fi stula. Abnormal development of the pharynx is not associated with a tracheoesophageal fi stula. GAS 168; GA 87
A 3-day-old male newborn has diffi culties in breathing. A CT scan of his chest and abdomen reveals the absence of the central tendon of the diaphragm. Which of the following structures failed to develop properly? ⃣ A. Pleuroperitoneal folds ⃣ B. Pleuropericardial folds ⃣ C. Septum transversum ⃣ D. Cervical myotomes ⃣ E. Dorsal mesentery of the esophagus
13 C. The septum transversum forms the central tendon of the diaphragm. The pleuroperitoneal folds form the posterolateral part of the diaphragm. The pleuropericardial folds separate the pericardial cavity from the pleural cavity and form the fi brous pericardium. The cervical myotomes form the musculature of the diaphragm. The dorsal part of the dorsal mesentery of the esophagus forms the crura of the diaphragm. GAS 156; GA 67
A 2-day-old female infant with fever is examined by the pediatric team. Imaging reveals malrotation of the small intestine without fi xation of the mesenteries. The vessels around the duodenojejunal junction are obstructed and the intestine is at risk of becoming gangrenous. Which of the following has occurred to cause the obstruction? ⃣ A. Diaphragmatic atresia ⃣ B. Subhepatic cecum ⃣ C. Midgut volvulus ⃣ D. Duplication of the intestine ⃣ E. Congenital megacolon
14 C. Midgut volvulus is a possible complication of malrotation of the midgut loop without fi xed mesentery. The small intestines twist around the vasculature that is providing support for them. This can result in ischemic necrosis of the intestine. Diaphragmatic atresia is not a cause of volvulus. Subhepatic cecum is due to failure of the descent of the cecal bud and results in the absence of an ascending colon. Duplication of the intestine would not cause volvulus because there would still be a fi xed mesentery and no free movement of the intestines. Congenital megacolon is due to faulty migration of neural crest cells into the wall of the colon, which causes a lack of parasympathetic postganglionic neurons. GAS 299; GA 154
15 A 5-day-old male infant is diagnosed with Hirschsprung disease. CT scan examination reveals an abnormally dilated colon. Which of the following is the most likely embryologic mechanism responsible for Hirschsprung disease? ⃣ A. Failure of neural crest cells to migrate into the walls of the colon ⃣ B. Incomplete separation of the cloaca ⃣ C. Failure of recanalization of the colon ⃣ D. Defective rotation of the hindgut ⃣ E. Oligohydramnios
15 A. Congenital megacolon (Hirschsprung disease) results from the failure of neural crest cells to migrate into the walls of the colon. Incomplete separation of the cloaca would result in anal agenesis either with or without the presence of a fi stula. The failure of recanalization of the colon results in rectal atresia, wherein both the anal canal and rectum exist but are not connected due to incomplete canalization or no recanalization. Defective rotation of the hindgut can cause volvulus or twisting of its contents. Oligohydramnios is a defi ciency of amniotic fl uid, which can cause pulmonary hypoplasia but would not cause Hirschsprung disease. GAS 311; GA 192
A 1-day-old infant has a mass protruding through her umbilicus. Physical examination reveals an umbilical hernia. A CT scan reveals that part of another organ is attached to the inner surface of the hernia. What portion of the gastrointestinal tract is most likely to be attached to the inner surface of the umbilical hernia? ⃣ A. Anal canal ⃣ B. Appendix ⃣ C. Cecum ⃣ D. Ileum ⃣ E. Stomach
D. The ileum is the best answer choice here because it is the most common site of Meckel diverticulum. This outpouching is a persistence of the vitelline duct and it can be attached to the umbilicus. The other answer choices are not correlated with the vitelline duct and therefore will not result in the condition discussed here. GAS 291; GA 155
A 38-year-old pregnant woman is admitted to the emergency department with severe vaginal bleeding. Ultrasound examination confi rms the initial diagnosis of ectopic pregnancy. Which of the following is the most common site of an ectopic pregnancy? ⃣ A. Uterine tubes ⃣ B. Cervix ⃣ C. Mesentery of the abdominal wall ⃣ D. Lower part of uterine body overlapping the internal cervical os ⃣ E. Fundus of the uterus
A. The most common site of ectopic pregnancy is in the uterine tubes. Implantation in the internal os of the cervix can result in placenta previa, but the internal os of the cervix is not the most common site. The other choices listed are not the most common sites of ectopic pregnancy. The fundus of the uterus is the normal site of implantation.
A 23-year-old woman is admitted with severe abdominal pain, nausea, and vomiting. History taking shows that the pain is acute and has been constant for 4 days. The pain began in the epigastric region and radiated bilaterally around the chest to just below the scapulae. Currently the pain is localized in the right hypochondrium. A CT scan examination reveals calcifi ed stones in the gallbladder. Which of the following nerves is carrying the afferent fi bers of the referred pain? ⃣ A. Greater thoracic splanchnic nerves ⃣ B. Dorsal primary rami of intercostal nerves ⃣ C. Phrenic nerves ⃣ D. Vagus nerves ⃣ E. Pelvic splanchnic nerves
A. The greater splanchnic nerve carries general visceral afferent fi bers from abdominal organs and can be involved in the occurrence of referred pain. The dorsal primary rami of intercostal nerves carry general somatic afferent fi bers. Pain from these fi bers would result in sharp, localized pain not dull and diffuse as occurs in referred pain. Although the phrenic nerve carries visceral afferent fi bers, it does not innervate the gallbladder. The vagus nerve carries visceral afferent fi bers that are important for visceral refl exes, but they do not transmit pain. The pelvic splanchnic nerves are parasympathetic nerves from S2 to S4 and contain visceral afferent fi bers that transmit pain from the pelvis but not from the gallbladder.
A 32-year-old male is admitted to the emergency department with groin pain. Examination reveals that the patient has an indirect inguinal hernia. Which of the following nerves is compressed by the herniating structure in the inguinal canal to give the patient pain? ⃣ A. Iliohypogastric ⃣ B. Lateral femoral cutaneous ⃣ C. Ilioinguinal ⃣ D. Subcostal ⃣ E. Pudendal
C. An indirect inguinal hernia occurs when a loop of bowel enters the spermatic cord through the deep inguinal ring (lateral to the inferior epigastric vessels). The ilioinguinal nerve runs with the spermatic cord to innervate the anterior portion of the scrotum and proximal parts of the genitals and could readily be compressed during an indirect inguinal hernia. The other nerves listed are not likely to be compressed by the hernia. The iliohypogastric nerve innervates the skin of the suprapubic region. The lateral femoral cutaneous nerve innervates the skin over the lateral thigh. The subcostal nerve innervates the band of skin superior to the iliac crest and inferior to the umbilicus. The pudendal nerve innervates the musculature and skin of the perineum. GAS 290; GA 140
A 54-year-old male is admitted to the emergency department with severe upper abdominal pain. Gastroscopy reveals a tumor in the antrum of the stomach. A CT scan is ordered to evaluate lymphatic drainage of the stomach. Which of the following lymph nodes is most likely to be involved in a malignancy of the stomach? ⃣ A. Celiac ⃣ B. Superior mesenteric ⃣ C. Inferior mesenteric ⃣ D. Lumbar ⃣ E. Hepatic
A. The celiac lymph nodes receive lymph drainage directly from the stomach before they drain into the cisterna chyli. The superior and inferior mesenteric lymph nodes receive drainage below the stomach and not from the stomach itself. The lumbar lymph nodes receive drainage from structures inferior to the stomach and not the stomach directly. Hepatic lymph nodes are associated with liver drainage and not drainage from the stomach.
During a scheduled laparoscopic cholecystectomy in a 47-year-old female patient, the resident accidentally clamped the hepatoduodenal ligament instead of the cystic artery. Which of the following vessels would most likely be occluded in this iatrogenic injury? ⃣ A. Superior mesenteric artery ⃣ B. Proper hepatic artery ⃣ C. Splenic artery ⃣ D. Common hepatic artery ⃣ E. Inferior vena cava
B. The proper hepatic artery is the only artery typically within the hepatoduodenal ligament and therefore would be occluded. This artery lies within the right anterior free margin of the omental (or epiploic) foramen (of Winslow). The superior mesenteric artery branches from the abdominal aorta inferior to the hepatoduodenal ligament. The splenic artery runs behind the stomach and is not located in the hepatoduodenal ligament. The common hepatic artery gives origin to the proper hepatic artery but does not run within the hepatoduodenal ligament. The inferior vena cava is located at the posterior margin of the omental foramen and therefore would not be clamped.
A 45-year-old male was admitted to the hospital with groin pain and a palpable mass just superior to the inguinal ligament. The patient was diagnosed with an inguinal hernia and a surgical repair was performed. During the operation the surgeon found a loop of intestine passing through the deep inguinal ring. Which of the following types of hernia was this? ⃣ A. Direct inguinal ⃣ B. Umbilical ⃣ C. Femoral ⃣ D. Lumbar ⃣ E. Indirect inguinal
E. Indirect hernias commonly result from herniation of the intestines through the deep inguinal ring. Direct hernias penetrate the anterior abdominal wall medial to the inferior epigastric vessels through the inguinal triangle (of Hesselbach) and do not penetrate the deep inguinal ring. Umbilical hernias exit through the umbilicus, not the deep inguinal ring. Femoral hernias exit through the femoral ring inferior to the inguinal ligament. Lumbar hernias can penetrate through superior (Grynfeltt) or inferior (Petit) lumbar triangles.
A 55-year-old man was admitted to the hospital with severe abdominal pain. Gastroscopy and CT scan examinations revealed a perforating ulcer in the posterior wall of the stomach. Where would peritonitis most likely develop initially? ⃣ A. Right subhepatic space ⃣ B. Hepatorenal space (of Morison) ⃣ C. Omental bursa (lesser sac) ⃣ D. Right subphrenic space ⃣ E. Greater sac
C. The omental bursa is located directly posterior to the stomach and therefore would be the most likely space to develop peritonitis initially. The right subhepatic space (also called the hepatorenal space, or pouch of Morison) is the area posterior to the liver and anterior to the right kidney. This space can potentially accumulate fl uid and may participate in peritonitis but primarily when the patient is in the supine position. The right subphrenic space lies just inferior to the diaphragm on the right side and is not likely to accumulate fl uid from a perforated stomach ulcer. Peritonitis could develop in this area only when the patient is in the supine position. Fluid from a perforated ulcer on the posterior aspect of the stomach is not likely to enter the greater sac.
A 58-year-old male alcoholic is admitted to the hospital after vomiting dark red blood (hematemesis). Endoscopy reveals ruptured esophageal varices, resulting from portal hypertension. Which of the following venous tributaries to the portal system anastomoses with caval veins to cause the varices? ⃣ A. Splenic ⃣ B. Left gastroomental ⃣ C. Left gastric ⃣ D. Left hepatic ⃣ E. Right gastric
24 C. The left gastric vein carries blood from the stomach to the portal vein. At the esophageal-gastric junction the left gastric vein (portal system) anastomoses with esophageal veins (caval system). High blood pressure in the portal system causes high pressure in this anastomosis, causing the ruptured esophageal varices. The splenic vein and its tributaries carry blood away from the spleen and do not form a caval-portal anastomosis. The left gastroomental vein accompanies the left gastroomental artery and joins the splenic vein with no direct anastomosis with caval veins. The left hepatic vein is a caval vein and empties into the inferior vena cava. The right gastric vein drains the lesser curvature of the stomach and is part of the portal system but does not have any caval anastomosis.
A 45-year-old male entered the emergency department with a complaint of severe abdominal pain. During physical examination it is observed that his cremasteric refl ex is absent. Which of the following nerves is responsible for the efferent limb of the cremasteric refl ex? ⃣ A. Ilioinguinal ⃣ B. Iliohypogastric ⃣ C. Genitofemoral ⃣ D. Pudendal ⃣ E. Ventral ramus of T12
C. The genitofemoral nerve originates from the ventral rami of L1 and L2. The femoral part supplies skin to the femoral triangle area, whereas the “genito” part in males travels with the spermatic cord and supplies the cremaster muscle and scrotal skin. The ilioinguinal nerve arises from L1 and supplies the skin over the root of the penis and upper part of the scrotum in the male. The iliohypogastric nerve arises from L1 (and possibly fi bers from T12) and supplies skin innervation over the hypogastric region and anterolateral gluteal region. The pudendal nerve provides innervation to the external genitalia for both sexes but does not innervate the cremaster muscle in males. The ventral ramus of T12 is also associated with the lower portion of the anterior abdominal wall and the iliohypogastric nerve; it does not contribute to the cremasteric refl ex.
The decision is made by emergency department surgeons to perform an exploratory laparotomy on a 32-year-old female with severe abdominal pain. Where would the incision most likely be made to separate the left and right rectus sheaths? ⃣ A. Midaxillary line ⃣ B. Arcuate line ⃣ C. Semilunar line ⃣ D. Tendinous intersection ⃣ E. Linea alba
E. The linea alba is formed by the intersection of aponeurotic tissues between the right and left rectus abdominal muscles. It contains the aponeuroses of the abdominal muscles and is located at the midline of the body. The midaxillary line is oriented vertically in a straight line inferior to the shoulder joint and axilla. The arcuate line (of Douglas) is a curved horizontal line that represents the lower edge of the posterior tendinous portion of the rectus abdominis sheath. An incision at this line will not separate the rectus abdominis sheaths. The semilunar line is represented by an imaginary vertical line below the nipples and usually parallels the lateral edge of the rectus sheath. The tendinous intersections of the rectus abdominis muscles divide the muscle into sections and are usually not well defi ned. An incision along these intersections would not divide the two rectus sheaths.
After a “tummy-tuck” (abdominoplasty) procedure is performed on a 45-year-old man, which of the following layers of the abdominal wall will hold the sutures? ⃣ A. Scarpa’s fascia (membranous layer) ⃣ B. Camper’s fascia (fatty layer) ⃣ C. Transversalis fascia ⃣ D. Extraperitoneal tissue ⃣ E. External abdominal oblique fascia
A. Scarpa’s fascia is the thick, membranous layer deep to the Camper’s adipose fascia in the anterior abdominal wall (subcutaneous). Because of the relatively thick, tough nature of connective tissue that makes up Scarpa’s fascia, this layer is typically the site to maintain sutures. Camper’s fascia is a fatty layer (subcutaneous) and tends not to hold sutures as well, due to the increased cellular content versus the connective tissue found in the Scarpa layer. Transversalis fascia is located deep to the abdominal musculature and associated aponeurosis. Extraperitoneal fascia is the deepest layer, adjacent to the parietal peritoneum of the anterior abdominal wall. The anterior wall of the rectus sheath is the layer just deep to Scarpa’s fascia and superfi cial to the rectus abdominis muscle anteriorly. The latter three layers are not considered to be superfi cial fascia.
A 49-year-old man presents with acute abdominal pain and jaundice. Radiographic studies reveal a tumor in the head of the pancreas. Which of the following structures is most likely being obstructed? ⃣ A. Common bile duct ⃣ B. Common hepatic duct ⃣ C. Cystic duct ⃣ D. Accessory pancreatic duct ⃣ E. Proper hepatic artery
A. The common bile duct is located at the head of the pancreas and receives contents from the cystic duct and hepatic duct. An obstruction at this site causes a backup of bile back through the common bile duct and hepatic duct, with resulting pain and jaundice. The common hepatic duct is located more superior to the head of the pancreas and leads into the cystic duct. The cystic duct allows bile to enter the gallbladder from the common bile duct (draining the liver) and releases bile to the common bile duct. The accessory pancreatic duct is not affected by an obstruction of the common bile duct due to a lack of any connections between the two ducts. The proper hepatic artery will not be obstructed, for it carries blood from the liver to the inferior vena cava.
A 44-year-old man is admitted to the emergency department with excessive vomiting and dehydration. Radiographic images demonstrate that part of the bowel is being compressed between the abdominal aorta and the superior mesenteric artery. Which of the following intestinal structures is most likely being compressed? ⃣ A. Second part of duodenum ⃣ B. Transverse colon ⃣ C. Third part of duodenum ⃣ D. First part of duodenum ⃣ E. Jejunum
C. The third part of the duodenum takes a path situated anterior to the abdominal aorta and inferior to the superior mesenteric artery (a major ventral branch of the abdominal aorta). Because the third part of the duodenum lies in the angle between (“sandwiched”) these two structures, constrictions of this portion of the duodenum can occur readily. The second part of the duodenum lies parallel with, and to the right of, the abdominal aorta and is not normally in close proximity to the superior mesenteric artery. The transverse colon takes a horizontal path through the anterior abdominal cavity but travels superior or anterior to the superior mesenteric artery. The fi rst part of the duodenum continues from the pylorus, fl exing to lead to the second part of the duodenum; thus, it is not located near the superior mesenteric artery or abdominal aorta. The jejunum is an extension of the small intestine after the duodenum and is further removed from the superior mesenteric artery.
During the surgical repair of a perforated duodenal ulcer in a 47-year-old male patient, the gastroduodenal artery is ligated. A branch of which of the following arteries will continue to supply blood to the pancreas in this patient? ⃣ A. Inferior mesenteric ⃣ B. Left gastric ⃣ C. Right gastric ⃣ D. Proper hepatic ⃣ E. Superior mesenteric
E. The superior mesenteric artery will supply the pancreas if the gastroduodenal artery is ligated. It arises immediately inferior to the celiac trunk from the thoracic aorta. Its fi rst branches are the anterior and posterior inferior pancreaticoduodenal arteries, which aid the superior pancreaticoduodenal arteries (which take origin from the gastroduodenal branch of the celiac trunk) in supplying the pancreas with oxygenated blood. The inferior mesenteric artery is the most inferior of the three main arterial branches supplying the gastrointestinal tract. It supplies the hindgut from the left colic fl exure to the rectum. The left gastric artery is the smallest branch of the celiac trunk and supplies the cardioesophageal junction, the inferior esophagus, and the lesser curvature of the stomach. Its anastomosis with branches from the thoracic aorta forms one of the four main portal-caval anastomoses. The right gastric artery arises from the common hepatic artery, which is a branch from the celiac trunk. It supplies the lesser curvature of the stomach and anastomoses with the left gastric artery. The proper hepatic artery arises from the common hepatic artery and ascends to supply the liver and gallbladder. It is one of three structures forming the portal triad and is found in the free edge of the hepatoduodenal ligament. GAS 333, 336; GA 169
A 70-year-old man is admitted to the emergency department with severe diarrhea. An arteriogram reveals 90% blockage at the origin of the inferior mesenteric artery from the aorta. Which of the following arteries would most likely provide collateral supply to the descending colon? ⃣ A. Left gastroepiploic artery ⃣ B. Middle colic artery ⃣ C. Sigmoid artery ⃣ D. Splenic artery ⃣ E. Superior rectal artery
B. The middle colic artery can provide collateral supply to the descending colon when the inferior mesenteric artery is blocked or ligated. It is one of the fi rst branches of the superior mesenteric artery and supplies the transverse colon. It provides collateral blood supply both to the ascending colon and descending colon by anastomosing with the right colic branch of the superior mesenteric artery and with the left colic artery, a branch from the inferior mesenteric artery. The left gastroepiploic artery, also known as the left gastroomental artery, is a branch of the splenic artery and supplies the greater curvature of the stomach along with the right gastroomental branch of the gastroduodenal artery. The sigmoid arteries are branches from the inferior mesenteric artery and supply the inferior portion of the descending colon, the sigmoid colon, and the rectum. The sigmoid arteries have no contributing branches to the foregut or midgut. The splenic artery is the largest artery arising from the celiac trunk. It supplies the spleen and the neck, body, and tail of the pancreas and also provides short gastric branches to the stomach. It supplies no structures in the midgut or hindgut. Finally, the superior rectal artery is the terminal branch of the inferior mesenteric artery and supplies only the rectum.
A 24-year-old woman has a dull aching pain in the umbilical region, and fl exion of the hip against resistance (psoas test) causes a sharp pain in the right lower abdominal quadrant. Which of the following structures is most likely infl amed to cause the pain? ⃣ A. Appendix ⃣ B. Bladder ⃣ C. Gallbladder ⃣ D. Pancreas ⃣ E. Uterus
A. The appendix is the most likely structure that is infl amed. It lies in the right lower quadrant, and of the choices provided, it is most closely associated with the umbilical region by way of referral of pain. The patient also exhibited a positive psoas sign when fl exion of the hip against resistance was attempted. This is because the iliopsoas muscle group lies directly beneath the appendix, and upon fl exion of this muscle group, contact and direct irritation to the appendix can occur. The bladder lies inferior to the umbilicus within the pelvis and is not related to the site of pain or with a positive psoas sign. The gallbladder lies inferior to the liver and is positioned in the upper right abdominal quadrant, which is superior to the umbilicus. It is not associated with a positive psoas sign. The pancreas lies behind the stomach and is positioned between the spleen and the duodenum. It therefore lies in the upper left quadrant and is superior to the umbilicus. The uterus is located within the pelvis and is positioned antefl exed and anteverted over the bladder. It lies inferior and medial to the iliopsoas group and would not be affected by fl exion of these muscles.
A 35-year-old male is admitted to the hospital from the emergency department because of excruciating pain in the back and left shoulder. A CT scan reveals an abscess in the upper part of the left kidney, but no abnormality is detected in the shoulder region. The shoulder pain may be caused by the spread of the infl ammation to which of the following neighboring structures? ⃣ A. Descending colon ⃣ B. Diaphragm ⃣ C. Duodenum ⃣ D. Liver ⃣ E. Pancreas
B. The abscess may have spread to the diaphragm and be causing the referred shoulder pain. This is because the diaphragm lies in close proximity to the inferior poles of the kidneys. The diaphragm is innervated by the phrenic nerves, bilaterally, which descend to the diaphragm from spinal nerve levels C3, C4, and C5. It is probably at the spinal cord that the referral of pain occurs between the phrenic nerve and somatic afferents entering at those levels. The descending colon is innervated by parasympathetic nerves from S2 to S4 and visceral afferents, which do not carry pain. The duodenum is innervated by the vagus nerve, which innervates the gastrointestinal tract to the left colic fl exure. The liver is innervated sympathetically from the celiac ganglion; the parasympathetic nerves to the liver are by the vagus nerve. Neither of these two sources of innervation enters the spinal cord at the level of the shoulder and therefore could not cause referred pain to the shoulder. The pancreas is innervated by the vagus nerve, branches from the celiac ganglion, and the pancreatic plexus. None of these nerves enters the spinal cord at the level of the shoulder and therefore cannot facilitate referral of pain to the shoulder.
A 62-year-old man is admitted to the hospital with dull, diffuse abdominal pain. A CT scan reveals a tumor at the head of the pancreas. The abdominal pain is mediated by afferent fi bers that travel initially with which of the following nerves? ⃣ A. Greater thoracic splanchnic ⃣ B. Intercostal ⃣ C. Phrenic ⃣ D. Vagus ⃣ E. Subcostal
A. The afferent fi bers mediating the pain from the head of the pancreas run initially with the greater thoracic splanchnic nerves. The greater splanchnic nerves arise from sympathetic ganglia at the levels of T5 to T9 and innervate structures of the foregut and thus the head of the pancreas. Running within these nerves are visceral afferent fi bers that relay pain from foregut structures to the dorsal horn of the spinal cord. Also entering the dorsal horn are the somatic afferents from that vertebral level, which mediate pain from the body wall. Intercostal nerves T1 to T12 provide the terminal part of the pathway to the spinal cord of visceral afferents for pain from the thorax and much of the abdomen. Therefore, pain fi bers from the pancreas pass by way of the splanchnic nerves to the sympathetic chains and then, by way of communicating rami, to ventral rami of intercostal nerves, fi nally entering the spinal cord by way of the dorsal roots. The phrenic nerve innervates the diaphragm and also carries visceral afferents from mediastinal pleura and the pericardium, but it does not carry with it any visceral afferent fi - bers from the pancreas. The vagus nerve innervates the pancreas with parasympathetic fi bers and ascends all the way up to the medulla where it enters the brain. It has no visceral afferent fi bers for pain. The subcostal nerve is from the level of T12 and innervates structures below the pancreas and carries no visceral afferents from the pancreas. GAS 318-319, 342; GA 191
A 52-year-old male with a history of smoking and hypercholesterolemia is diagnosed with severe atherosclerosis affecting the arteries of his body. Laboratory examination reveals extremely low sperm count. Which of the following arteries is most likely occluded? ⃣ A. External iliac ⃣ B. Inferior epigastric ⃣ C. Umbilical ⃣ D. Testicular ⃣ E. Deep circumfl ex iliac
D. The testicular artery originates from the abdominal aorta and travels with the spermatic cord, leading to the testes in the male. The external iliac artery is located “downstream” to the origin of the testicular artery from the aorta and would not cause any problems in sperm count. The inferior epigastric artery originates close to the deep inguinal ring (spermatic cord exit) as a branch of the external iliac artery and is not associated with the testicular production of sperm. The umbilical artery originates from the internal iliac artery and is divided in adults: one part is obliterated (medial umbilical artery), and the other part gives origin to superior vesical arteries to the urinary bladder. The umbilical artery plays no role in sperm production.
In a routine visit to the outpatient clinic for his annual checkup, a 42-year-old male is informed that radiographic examination has given strong evidence that he has a malignancy of his scrotum. Which of the following nodes are the fi rst lymph nodes that drain the affected area? ⃣ A. Superfi cial inguinal ⃣ B. Internal iliac ⃣ C. Lumbar ⃣ D. Presacral ⃣ E. Axillary
A. The lymph drainage of the scrotum is into the superfi cial inguinal nodes. The internal iliac lymph nodes drain the pelvis, perineum, and gluteal region. The lumbar nodes drain lymph from kidneys, the adrenal glands, testes or ovaries, uterus, and uterine tubes. They also receive lymph from the common internal or external nodes. Axillary lymph nodes drain the anterior abdominal wall above the umbilicus. GAS 494; GA 254
A 35-year-old male is admitted to the hospital with an indirect inguinal hernia. During an open hernioplasty (in contrast to a laparoscopic procedure), the spermatic cord and the internal abdominal oblique muscles are identifi ed. Which component of the spermatic cord is derived from the internal abdominal oblique muscle? ⃣ A. External spermatic fascia ⃣ B. Cremaster muscle ⃣ C. Tunica vaginalis ⃣ D. Internal spermatic fascia ⃣ E. Dartos fascia
B. The contents of the spermatic cord include ductus deferens; testicular, cremasteric, and deferential arteries; the pampiniform plexus of testicular nerve; the genital branch of the genitofemoral nerve; the cremasteric nerves; and the testicular sympathetic plexus and also lymph vessels. The cremaster muscle and fascia originate from the internal abdominal oblique muscle. The external spermatic fascia is derived from the aponeurosis and fascia of the external oblique muscle. The tunica vaginalis is a continuation of the processus vaginalis (from parietal peritoneum) that covers the anterior and lateral sides of the testes and epididymis. The internal spermatic fascia is derived from the transversalis fascia. The dartos tunic consists of a blending of the adipose (Camper) and membranous (Scarpa) layers of the superfi cial fascia, with interspersed smooth muscle fi bers.
A 63-year-old man with a history of alcoholism is brought to the emergency department with hematemesis (vomiting blood). Findings on endoscopic examination suggest bleeding from esophageal varices. The varices are most likely a result of the anastomoses between the left gastric vein and which other vessel or vessels? ⃣ A. Azygos system of veins ⃣ B. Inferior vena cava ⃣ C. Left umbilical vein ⃣ D. Superior mesenteric vein ⃣ E. Subcostal veins
A. Esophageal varices are dilated veins in the submucosa of the lower esophagus. They often result from portal hypertension due to liver cirrhosis. The left gastric vein and the esophageal veins of the azygos system form an important portal-caval anastomosis when pressure in the portal vein, and in turn the left gastric vein, is increased. None of the other choices forms important portal-caval anastomoses.
A 34-year-old man is undergoing an emergency appendectomy. After the appendectomy has been performed successfully, the patient undergoes an exploratory laparoscopy. Which of the following anatomic features are the most useful to distinguish the jejunum from the ileum? ⃣ A. Jejunum has thinner walls compared with the ileum. ⃣ B. Jejunum has less mesenteric fat compared with the ileum. ⃣ C. Jejunum has more numerous vascular arcades compared with the ileum. ⃣ D. Jejunum has more numerous lymphatic follicles beneath the mucosa compared with the ileum. ⃣ E. Jejunum has fewer villi compared with the ileum.
B. The jejunum makes up the proximal two fi fths of the small intestine. There are several ways in which the ileum and jejunum differ. During surgery the easiest way to distinguish the two based on appearance is the relative amount of mesenteric fat. The jejunum has less mesenteric fat than the ileum. Although the jejunum does have thicker walls, more villi, and higher plicae circulares compared with the ileum, these distinctions are not visible unless the intestinal wall is incised. The jejunum has fewer vascular arcades in comparison with the ileum. Lymphatic follicles are visible, usually only histologically, in the ileum.
After a mastectomy, a musculocutaneous fl ap is used to restore the thoracic contour in a 34-year-old female patient. The ipsilateral (same side) rectus abdominis muscle was detached carefully from the surrounding structures and transposed to the thoracic wall. Which of the following landmarks is most often used to locate the inferior end of the posterior, tendinous layer of the rectus sheath? ⃣ A. Intercristal line ⃣ B. Linea alba ⃣ C. Arcuate line ⃣ D. Pectineal line ⃣ E. Semilunar line
C. The arcuate line is a horizontal line that demarcates the lower limit of the posterior aponeurotic portion of the rectus sheath. It is also where the inferior epigastric vessels perforate the sheath to enter the rectus abdominis. The intercristal line is an imaginary line drawn in the horizontal plane at the upper margin of the iliac crests. The linea alba is a tendinous, median raphe running vertically between the two rectus abdominis muscles from the xiphoid process to the pubic symphysis. The pectineal line is a feature of the superior ramus of the pubic bone; it provides an origin for the pectineus muscle of the thigh and medial insertions for the abdominal obliques and transversus muscles. The semilunar line is the curved, vertical line along the lateral border of the sheath of the rectus abdominis.
An anteroposterior radiograph is taken of the lumbar region in a 31-year-old female patient who had been treated for tuberculous spondylitis at vertebral levels T12-L1. The patient has been asymptomatic for 10 years. Which of the following is the most likely site of the calcifi ed tuberculous abscess? ⃣ A. Body of pancreas ⃣ B. Cecum ⃣ C. Fundus of stomach ⃣ D. Psoas fascia ⃣ E. Suspensory ligament of the duodenum
D. The psoas muscles (covered in psoas fascia) originate from the transverse processes, intervertebral disks, and bodies of the vertebral column at levels T12 to L5. In the image, this fascia contains a calcifi ed tuberculous abscess. The pancreas is an elongated organ located across the back of the abdomen, behind the stomach. The tapering body extends horizontally and slightly upward to the left and ends near the spleen. The cecum is the blind-ending pouch of the ascending colon, lying in the right iliac fossa. The fundus of the stomach lies inferior to the apex of the heart at the level of the fi fth rib. The suspensory ligament of the duodenum is a fi bromuscular band that attaches to the right crus of the diaphragm.
A 45-year-old female is admitted to the hospital with symptoms of an upper bowel obstruction. Upon CT examination it is found that the third (transverse) portion of the duodenum is being compressed by a large vessel. Which of the following vessels will most likely be causing the compression? ⃣ A. Inferior mesenteric artery ⃣ B. Superior mesenteric artery ⃣ C. Inferior mesenteric vein ⃣ D. Portal vein ⃣ E. Splenic vein
B. The superior mesenteric artery arises from the aorta, behind the neck of the pancreas, and descends across the uncinate process of the pancreas and the third part of the duodenum before it enters the root of the mesentery behind the transverse colon. It can compress the third part of the duodenum. The inferior mesenteric artery passes to the left behind the horizontal portion of the duodenum. The inferior mesenteric vein is formed by the union of the superior rectal and sigmoid veins and it does not cross the third part of the duodenum. The portal vein is formed by the union of the splenic vein and the superior mesenteric vein posterior to the neck of the pancreas. It ascends behind the bile duct and the hepatic artery within the free margin of the hepatoduodenal ligament. The splenic vein is formed by the tributaries from the spleen and is superior to the third part of the duodenum.
A 61-year-old woman had been scheduled for a cholecystectomy. During the operation the scissors of the surgical resident accidentally entered the tissues immediately posterior to the epiploic (omental) foramen (its posterior boundary). The surgical fi eld was fi lled immediately by profuse bleeding. Which of the following vessels was the most likely source of bleeding? ⃣ A. Aorta ⃣ B. Inferior vena cava ⃣ C. Portal vein ⃣ D. Right renal artery ⃣ E. Superior mesenteric vein
B. The omental (epiploic) foramen (of Winslow) is the only natural opening between the lesser and greater sacs of the peritoneal cavity. It is bounded superiorly by the visceral peritoneum (liver capsule of Glisson) on the caudate lobe of the liver, inferiorly by the peritoneum on the fi rst part of the duodenum, anteriorly by the free edge of the hepatoduodenal ligament, and posteriorly by the parietal peritoneum covering the inferior vena cava. Therefore, the inferior vena cava would be the most likely source of bleeding. The aorta lies to the left of the inferior vena cava in the abdomen. The portal vein, right renal artery, and superior mesenteric vein are not borders of the epiploic foramen
A 32-year-old woman was admitted to the hospital with a complaint of pain over her umbilicus. Radiographic examination revealed acute appendicitis. The appendix was removed successfully in an emergency appendectomy. One week postoperatively the patient complained of paresthesia of the skin over the pubic region and the anterior portion of her perineum. Which of the following nerves was most likely injured during the appendectomy? ⃣ A. Genitofemoral ⃣ B. Ilioinguinal ⃣ C. Subcostal ⃣ D. Iliohypogastric ⃣ E. Spinal nerve T9
B. The ilioinguinal nerve, which arises from the L1 spinal nerve, innervates the skin on the medial aspect of the thigh, scrotum (or labia majora), and the mons pubis. It has been injured in this patient. The genitofemoral nerve splits into two branches: The genital branch supplies the scrotum (or labia majora) whereas the femoral branch supplies the skin of the femoral triangle. The subcostal nerve has a lateral cutaneous branch that innervates skin in the upper gluteal region, in addition to distribution over the lower part of the anterior abdominal wall. The iliohypogastric nerve innervates the skin over the iliac crest and the hypogastric region. Spinal nerve T9 supplies sensory innervation to the dermatome at the level of T9, above the level of the umbilicus.
Exploratory laparoscopy was performed on a 34-year-old male, following a successful emergency appendectomy. Which of the following anatomic relationships would be seen clearly, without dissection, when the surgeon exposes the beginning of the jejunum? A. ⃣ The second portion of the duodenum is related anteriorly to the hilum of the right kidney. ⃣ B. The superior mesenteric artery and vein pass posterior to the third part of the duodenum. ⃣ C. The portal vein crosses anterior to the neck of the pancreas. ⃣ D. The second part of the duodenum is crossed anteriorly by the attachment of the transverse mesocolon. ⃣ E. The third part of the duodenum is related anteriorly to the hilum of the left kidney
D. The second part of the duodenum is crossed anteriorly by the transverse mesocolon, a relationship that can be seen when the beginning of the jejunum is exposed by lifting the transverse colon superiorly. The posterior relationships of the second part of the duodenum and the portal vein cannot be seen without some dissection. The third part of the duodenum is not related anteriorly to the hilum of the left kidney.
A 30-year-old female patient complains that she has been weak and easily fatigued over the past 6 months. She has a 3-month acute history of severe hypertension that has required treatment with antihypertensive medications. She has recently gained 4.5 kg (10 lb) and currently weighs 75 kg (165 lb). Her blood pressure is 170/100 mm Hg. Purple striae are seen over the abdomen on physical examination and she possesses a “buffalo hump.” Fasting serum glucose concentration is 140 mg/dl. A CT scan of the abdomen shows a 6-cm mass immediately posterior to the inferior vena cava. Which of the following organs is the most likely origin of the mass? ⃣ A. Suprarenal (adrenal) gland ⃣ B. Appendix ⃣ C. Gallbladder ⃣ D. Ovary ⃣ E. Uterus
A. The right adrenal gland is a retroperitoneal organ on the superomedial aspect of the right kidney, partially posterior to the inferior vena cava. The appendix is a narrow, hollow tube that is suspended from the cecum by a small mesoappendix. The gallbladder is located at the junction of the ninth costal cartilage and the lateral border of the rectus abdominis, quite anterior to the pathologic mass. The ovaries and uterus are both inferior to the confl uence of the inferior vena cava.
An obese 45-year-old female patient with an elevated temperature comes to the physician’s offi ce complaining of nausea and intermittent, acute pain in the right upper quadrant of the abdomen during the past 2 days. She has a 24-hour history of jaundice. She has a history of gallstones. Which of the following structures has most likely been obstructed by a gallstone? ⃣ A. Common bile duct ⃣ B. Cystic duct ⃣ C. Left hepatic duct ⃣ D. Pancreatic duct ⃣ E. Right hepatic duct
A. The symptoms of yellow eyes and jaundice would be caused by reversal of fl ow of bile into the bloodstream. The common bile duct, if obstructed, allows no collateral pathway for drainage of bile from the liver or gallbladder. The cystic duct would block gallbladder drainage but allow for bile fl ow from the liver. Obstruction of either the right or left hepatic duct would still allow for drainage from the liver, as well as the gallbladder. The pancreatic duct is not involved in the path of bile fl ow from the liver to the duodenum. It drains pancreatic enzymes from the pancreas to the duodenum.
A 67-year-old man has severe cirrhosis of the liver. He most likely has enlarged anastomoses between which of the following pairs of veins? ⃣ A. Inferior phrenic and superior phrenic ⃣ B. Left colic and middle colic ⃣ C. Left gastric and esophageal ⃣ D. Lumbar and renal ⃣ E. Sigmoid and superior rectal
C. Cirrhosis of the liver would lead to inability of the portal system to accommodate blood fl ow. Blood backs up toward systemic circulation, draining to the inferior vena cava, with pooling at areas of portal-caval anastomoses. The left gastric vein (portal) meets the esophageal vein (caval) and enlarges or expands in instances of cirrhosis. The left colic and middle colic veins are both simply tributaries to the portal system, excluding this as the correct answer. The inferior phrenic and superior phrenic veins are both systemic veins and would not be affected by portal hypertension. The same can be said for the renal and lumbar veins, both components of the caval-systemic venous system. The sigmoidal and superior rectal veins are both components of the portal venous system and would not engorge due to the portal-caval bottleneck experienced in cirrhosis. (The anastomoses between the superior rectal veins and middle or inferior rectal veins can expand in portal hypertension as hemorrhoids.)
A 45-year-old male is admitted to the hospital with a massive hernia that passes through the inguinal triangle (of Hesselbach). Which of the following structures is used to distinguish a direct inguinal hernia from an indirect inguinal hernia? ⃣ A. Inferior epigastric vessels ⃣ B. Femoral canal ⃣ C. Inguinal ligament ⃣ D. Rectus abdominis muscle (lateral border) ⃣ E. Pectineal ligament
A. The key distinguishing feature of a direct inguinal hernia is that the direct hernia does not pass through the deep inguinal ring; it passes through the lower portion of the inguinal triangle (of Hesselbach). This triangle is bordered laterally by the inferior epigastric artery and vein; medially, it is bordered by the lateral edge of rectus abdominis; inferiorly, it is bordered by the iliopubic tract and inguinal ligament. An indirect hernia passes through the deep inguinal ring and into the inguinal canal. It often descends through the superfi cial ring into the scrotum or labium, a feature less common in a direct inguinal hernia. If the tip of the examiner’s little fi nger is inserted into the superfi cial ring, and the patient is asked to cough, an indirect inguinal hernia may be felt hitting the very tip of the little fi nger. A direct inguinal hernia will be felt against the side of the digit. Both types of inguinal hernias occur above the inguinal ligament, and both are present lateral to the lateral border of the rectus abdominis. The pubic symphysis, a midline joint between the two pubic bones, provides no information for distinguishing types of hernias. The femoral canal, a feature of the femoral sheath, passes beneath the inguinal ligament into the thigh, providing the pathway taken by a femoral hernia. The pectineal ligament lies behind, or deep to, the proximal end of the femoral canal.
A 36-year-old man was brought to the emergency department with a bullet wound to the abdomen. The bullet penetrated the anterior abdominal wall superior to the umbilicus. If the bullet passed directly posterior in the midline, which of the following structures was most likely to have been struck fi rst by the bullet? ⃣ A. Abdominal aorta ⃣ B. Transverse colon ⃣ C. Stomach ⃣ D. Gallbladder ⃣ E. Pancreas
B. The bullet would probably fi rst penetrate the transverse colon because it is the most superfi cial structure located slightly superior to the umbilicus. The abdominal aorta is located deep, on the left side of the vertebral column, and would not be encountered fi rst. The stomach is located more superior, to the left, and posterior to the transverse colon and would not be affected by the anterior-posterior trajectory of the bullet. The pancreas is located deep to the stomach and duodenum. The gallbladder is located superiorly in the upper right quadrant of the abdomen, largely under cover of the liver. This would exclude its possibility of being penetrated by the midline bullet.
A 48-year-old man has had three episodes of upper gastrointestinal bleeding from esophageal varices. He has a history of chronic alcoholism but has recently been rehabilitated. Further evaluation shows ascites and splenomegaly. Which of the following surgical venous anastomoses is most commonly used to relieve these symptoms and signs before a liver transplant is attempted? ⃣ A. Left gastric to splenic vein ⃣ B. Right gastric to left gastric vein ⃣ C. Right renal to right gonadal vein ⃣ D. Splenic to left renal vein ⃣ E. Superior mesenteric to inferior mesenteric vein
D. Surgical anastomoses to alleviate symptoms of portal hypertension are rooted in the premise that connection of a large portal vein to a large systemic vein allows for collateral drainage of the portal system. The splenic vein, a component of the portal venous system, and the left renal vein, a component of the caval-systemic venous system, are ideally located to allow for a low-resistance, easily performed anastomosis. Anastomosing the left gastric vein to the splenic vein, the right gastric vein to the left gastric vein, or the superior mesenteric vein to the inferior mesenteric vein would all be ineffectual because each of these veins is a component of just the portal venous system. In addition, the right renal and right gonadal veins are both tributaries of the caval system, and surgical connection would provide no benefi t.
A 55-year-old man is admitted to the hospital with nausea, vomiting, and hematuria. A CT scan examination reveals a neoplasm in the posterior surface of the inferior pole of the left kidney that has invaded through the renal pelvis, renal capsule, ureter, and fat. To which of the following regions will pain most likely be referred? ⃣ A. Skin of the anterior and lateral thighs and femoral triangle ⃣ B. Skin over the gluteal region, pubis, medial thigh, and scrotal areas ⃣ C. Skin over the medial, anterior, and lateral side of the thigh ⃣ D. Skin over the pubis and umbilicus ⃣ E. Skin over the pubis, umbilicus, and posterior abdominal wall muscles
B. Visceral pain from the kidneys and the ureter at the point of the neoplasm is mediated via T11 and T12 spinal cord levels. Therefore, pain is referred to these dermatomes leading to pain in the upper gluteal, pubic, medial thigh, scrotal, and labial areas (from subcostal and iliohypogastric nerves, in particular). In contrast, the umbilical region, the T10 dermatome, is supplied by the T10 spinal nerve, excluding it from being the correct answer. The dermatomes that supply the anterior and lateral thighs are of upper lumbar origin and would not receive pain referred from the kidneys.
A 30-year-old female patient has complained of weakness and fatigability over the past 6 months. She has a 3-month acute history of severe hypertension that has not responded to antihypertensive medications. Fasting serum glucose concentration is 140 mg/dl. A CT scan of the abdomen shows a 6-cm mass in the adrenal gland affecting the secretory cells of the adrenal medulla. Which of the following structures is most likely releasing products into the bloodstream to produce the hypertension and other signs? ⃣ A. Preganglionic sympathetic axons in thoracic splanchnic nerves ⃣ B. Cells of neural crest origin that migrated to the adrenal medulla ⃣ C. Preganglionic parasympathetic branches of the posterior vagal trunk ⃣ D. Postganglionic parasympathetic branches of the left or right vagus nerves ⃣ E. Postganglionic fi bers from pelvic splanchnic nerves
B. The mass leads to increased stimulation and secretions of the chromaffi n cells of the adrenal medulla. These cells are modifi ed postganglionic sympathetic neurons of neural crest origin, and the epinephrine (adrenaline) and norepinephrine (noradrenaline) released by these cells passes into the suprarenal (adrenal) veins. The adrenal medulla receives stimulation from preganglionic sympathetic fi bers carried by the thoracic splanchnic nerves. Parasympathetic neurons are not found in the adrenal medulla and would have no participation in the effects of the tumor. In addition, the pelvic splanchnic nerves are parasympathetic and do not travel to the adrenal medulla.
A 48-year-old man is admitted to the hospital with severe abdominal pain. Radiographic examination reveals a tumor in the tail of the pancreas. A diagnostic arteriogram shows that the tumor has compromised the blood supply to another organ. Which of the fol- ABDOMEN 64 lowing organs is most likely to have its blood supply compromised by this tumor? ⃣ A. Duodenum ⃣ B. Gallbladder ⃣ C. Kidney ⃣ D. Liver ⃣ E. Spleen
E. The splenic artery lies adjacent to the superior border of the pancreas. The organ it principally supplies is the spleen, which is located at the termination of the pancreatic tail. Blood supply to the spleen can therefore be affected in the event of a tumor in the tail of the pancreas. The duodenum receives blood from the gastroduodenal artery, located near the head of the pancreas. The gallbladder is supplied by the cystic artery, a branch of the hepatic artery and is not in contact with the pancreas. The liver is also supplied by the hepatic artery. The kidneys are supplied by the right and left renal arteries. The left renal artery lies deep and medial to the pancreatic tumor, and blood supply would proceed uninterrupted.
A 57-year-old man is admitted to the emergency department with left fl ank pain. Blood tests indicate hematuria and anemia. A magnetic resonance scan reveals that blood fl ow in the left renal vein is being occluded by an arterial aneurysm where the vein crosses the aorta. The aneurysm is most likely located in which of the following arteries? ⃣ A. Celiac ⃣ B. Inferior mesenteric ⃣ C. Left colic ⃣ D. Middle colic ⃣ E. Superior mesenteric
E. The superior mesenteric artery lies just superior and anterior to the left renal vein as the vein passes to its termination in the inferior vena cava. The celiac artery is located superiorly and would not compress the left renal vein. The inferior mesenteric artery and its left colic branch are located too inferiorly to occlude the left renal vein. The middle colic artery arises from the anterior aspect of the superior mesenteric artery inferior to the position of the left renal vein. An aneurysm of the superior mesenteric artery would therefore be most likely to occlude the left renal vein.
A 57-year-old man is admitted to the emergency department with pain in his left fl ank and testicles. Laboratory tests indicate hematuria and anemia. A CT scan examination provides evidence that blood fl ow in the left renal vein is being occluded where it crosses anterior to the aorta. Which of the following is the most likely cause of the testicular pain? ⃣ A. Compression of the testicular artery ⃣ B. Occlusion of fl ow of blood in the testicular vein ⃣ C. Compression of the afferent fi bers in the lumbar splanchnic nerves ⃣ D. Compression of the sympathetic fi bers in the preaortic plexus ⃣ E. Compression of the posterior vagus nerve
B. Blood fl ow would be impeded or greatly reduced in the left testicular vein because of the occlusion of the left renal vein—into which the left testicular vein drains. This would result in pain as the testicular venous vessels become swollen. The testicular artery originates from the abdominal aorta more inferiorly and is not being compressed. Pain mediated from the renal organs would pass to the T11 and T12 spinal cord levels via the thoracic splanchnic nerves. There would be no compression of lumbar splanchnic nerves in this case. Compression of the preaortic sympathetics would not produce pain, nor would it cause referral of pain. Visceral afferents for pain terminate at the T7 level of the spinal cord. The vagus, a parasympathetic nerve, does not carry visceral pain fi bers in the abdomen; pain is mediated by branches of the sympathetic chains.
A 51-year-old woman is admitted to the hospital with an acutely painful abdomen. Radiographic examination reveals penetration of the fundic region of the stomach by an ulcer, resulting in intraabdominal bleeding. Which of the following arteries is the most likely source of the bleeding? ⃣ A. Common hepatic artery ⃣ B. Inferior phrenic artery ⃣ C. Left gastroepiploic artery ⃣ D. Short gastric artery ⃣ E. Splenic artery
D. The most likely candidate for bleeding from the fundic region of the stomach in this case would be either the short gastric or dorsal gastric branches of the splenic artery. The short gastric arteries pass from the area of the splenic hilum to the fundus, supplying anterior and posterior branches to this part of the stomach. The dorsal gastric artery, which arises from the midportion of the splenic artery, passes to the dorsal aspect of the fundus. The main stem of the splenic artery would pass somewhat inferior to the location of the ulceration. The common hepatic artery and inferior phrenic artery are quite removed from the area of the ulcer. The left gastroepiploic artery courses along the greater curvature of the body of the stomach, distal to the fundus.
A 39-year-old woman is admitted to the hospital with pain radiating to her inguinal region. Radiographic and physical examination reveal a herniation. Which of the following is the most common type of hernia in a female patient? ⃣ A. Femoral hernia ⃣ B. Umbilical hernia ⃣ C. Direct inguinal hernia ⃣ D. Indirect inguinal hernia ⃣ E. Epigastric hernia
D. Indirect inguinal hernia is the most common groin hernia in females. Although femoral hernias occur more commonly in females than in males, the occurrence of indirect inguinal hernias in women is greater. Inguinal hernias are much more common in males than in females. Epigastric and umbilical hernias would not present with pain to the inguinal region. Direct inguinal hernias, while exhibiting equal incidence in both sexes, are not the most common female hernia.
Radiographic examination of a 42-year-old female reveals penetration of the duodenal bulb by an ulcer, resulting in profuse intraabdominal bleeding. Which of the following arteries is the most likely source of the bleeding? ⃣ A. Posterior superior pancreaticoduodenal ⃣ B. Superior mesenteric ⃣ C. Inferior mesenteric ⃣ D. Inferior pancreaticoduodenal ⃣ E. Right gastric
A. The posterior superior pancreaticoduodenal artery arises from the gastroduodenal artery and travels behind the fi rst part of the duodenum, supplying the proximal portion, with branches to the head of the pancreas. Duodenal ulcers commonly arise within the fi rst portion of the duodenum, thus making the posterior superior pancreaticoduodenal artery one of the more frequently injured vessels. The superior mesenteric artery supplies derivatives of the midgut from the distal half of the duodenum to the left colic fl exure. It lies inferior to the region of ulceration. The inferior pancreaticoduodenal artery arises from the superior mesenteric artery and supplies the distal portion of the second part of the duodenum, with anastomoses with its superior counterparts. The inferior mesenteric artery is responsible for supplying most of the hindgut derivatives, generally supplying intestine from the left colic fl exure to the superior aspect of the rectum. The right gastric artery is responsible for supplying the pyloric portion of the lesser curvature of the stomach.
A 23-year-old man is admitted to the hospital with a bulge in his scrotum. Physical examination reveals an indirect inguinal hernia. During the open hernia repair the internal spermatic fascia is identifi ed and refl ected to expose the ductus deferens and testicular vessels. Which of the following provides the internal spermatic fascial layer of the spermatic cord? ⃣ A. External abdominal oblique aponeurosis ⃣ B. Internal abdominal oblique aponeurosis ⃣ C. Transversus abdominis aponeurosis ⃣ D. Transversalis fascia ⃣ E. Processus vaginalis
D. The transversalis fascial layer is the source of the internal spermatic fascia. The walls of the spermatic cord consist of three layers: external spermatic fascia, cremaster muscle, and the internal spermatic fascia. The external spermatic fascia is an extension of the external oblique fascia and aponeurosis. The cremaster muscle is a derivative of the internal oblique abdominal muscle and its fascia. The processus vaginalis is a pouch of peritoneum that precedes the testis as it descends through the deep inguinal ring and inguinal canal in the seventh month of development. That portion of the processus that is normally retained forms the tunica vaginalis of the testis. Retention of the proximal part of the processus provides a pathway for a congenital indirect inguinal hernia. If a portion of the intermediate part of the processus remains, it can form a fl uid-fi lled hydrocele.
A 45-year-old woman is admitted to the emergency department with a complaint of severe abdominal pain. CT scan and MRI examinations reveal a tumor of the head of the pancreas involving the uncinate process. Which of the following vessels is most likely to be occluded? ⃣ A. Common hepatic artery ⃣ B. Cystic artery and vein ⃣ C. Superior mesenteric artery ⃣ D. Inferior mesenteric artery ⃣ E. Portal vein
C. The superior mesenteric artery arises from the aorta, deep to the neck of the pancreas, then crosses the uncinate process and third part of the duodenum. An uncinate tumor can cause compression of the superior mesenteric artery. The common hepatic artery arises superior to the body of the pancreas and is unlikely to be affected by a tumor in the uncinate region of the pancreas. The cystic artery and vein, supplying the gallbladder, are also superior to the pancreas. The inferior mesenteric artery arises at the level of L3, which is thus situated deep to and inferior to the head of the pancreas. The portal vein, formed by the confl uence of the superior mesenteric vein and splenic vein, passes deep to the neck of the pancreas.
A 35-year-old obese man is admitted to the hospital with jaundice and complaints of abdominal pain. Physical examination reveals an epigastric pain that migrates toward the patient’s right side and posterior toward the scapula. Radiographic examination reveals multiple gallstones, consistent with the patient’s jaundice and typical pains of cholecystitis. Which of the following structures is most likely obstructed by the gallstones? ⃣ A. Common bile duct ⃣ B. Cystic duct ⃣ C. Left hepatic duct ⃣ D. Pancreatic duct ⃣ E. Right hepatic duct
The common bile duct is occluded. The pattern of pain of cholecystitis (and other signs), combined with jaundice, indicates blockage of release of bile into the duodenum. The cystic duct joins the common hepatic duct to form the common bile duct. Bile is released from the gallbladder into the cystic duct in response to cholecystokinin. From the cystic duct, bile fl ows normally through the common bile duct and the hepatopancreatic ampulla (of Vater) to enter the descending duodenum. Patients will often present with multiple gallstones. Cholecystitis is an infl ammation of the gallbladder, most frequently in association with the presence of gallstones, and often resulting from a blocked cystic duct. Increasing concentration of bile in the gallbladder can precipitate a bout of infl ammation. Blockage of the cystic duct, with concomitant cholecystitis, is not necessarily associated with jaundice. An obstruction in the common hepatic duct and subsequently the common bile duct would thus prevent communication between the duodenum and the liver, causing obstructive jaundice. An occlusion in either the left or right hepatic duct might cause mild jaundice; however, gallstones might not be present. An occlusion in the pancreatic duct would result in neither gallstones nor jaundice but may cause pancreatitis.
A 36-year-old woman is admitted to the hospital for the imminent birth of her baby. The decision is made to perform an emergency cesarean section. A Pfannenstiel incision is used to reach the uterus by making a transverse incision through the external sheath of the rectus muscles, about 2 cm above the pubic bones. It follows natural folds of the skin and curves superior to the mons pubis. Which of the following nerves is most at risk when this incision is made? ⃣ A. T10 ⃣ B. T11 ⃣ C. Iliohypogastric ⃣ D. Ilioinguinal ⃣ E. Lateral femoral cutaneous
C. The anterior cutaneous branch of the iliohypogastric nerve is responsible for the innervation of the skin above the mons pubis. This nerve arises from the T12 and L1 spinal nerves and runs transversely around the abdominal wall and over the lowest portion of the rectus sheath. It is the fi rst cutaneous nerve situated superior to the mons pubis. Nerves from the T11 and the T12 ventral rami terminate below the umbilicus but superior to the mons pubis. The ilioinguinal nerve courses through the inguinal canal, commonly on the lateral side of the spermatic cord and is therefore typically inferior to the incision. The lateral femoral cutaneous nerve travels lateral to the psoas muscle and emerges from the abdomen about an inch medial to the anterior superior iliac spine, passing thereafter to the lateral aspect of the thigh.
A 37-year-old woman was admitted to the emergency department with high fever (39.5° C), nausea, and vomiting. Physical examination revealed increased abdominal pain in the paraumbilical region, rebound tenderness over McBurney’s point, and a positive psoas test. Blood tests showed marked leukocytosis. Which of the following is the most likely diagnosis? ⃣ A. Ectopic pregnancy ⃣ B. Appendicitis ⃣ C. Cholecystitis ⃣ D. Kidney stone ⃣ E. Perforation of the duodenum
B. Appendicitis is often characterized by acute infl ammation and is indicated with both a positive psoas test and rebound pain over McBurney’s point. McBurney’s point lies 1 inch lateral to the midpoint of an imaginary line in the right lower quadrant, joining the anterior superior iliac spine and the umbilicus. In patients with appendicitis, rebound tenderness may be felt over McBurney’s point after quick, deep compression of the left lower quadrant. An ectopic pregnancy would be associated with generalized abdominal pain instead of the localized pain felt over McBurney’s point. Cholecystitis results from an infl ammation of the gallbladder and would result in pain over the epigastric region shifting to the right hypochondriac region. Kidney stones result in referred pain to the lumbar or possibly inguinal regions. Perforation of the duodenum could result in pain to palpation of the abdomen, together with adynamic (paralytic) ileus, rigidity of the abdominal wall, and referral of pain to the shoulder.
A 56-year-old male is admitted to the hospital with severe abdominal pain. The patient has a history of “irritable bowel syndrome” affecting his rectum. Which of the following nerves will most likely be responsible for the transmission of pain in this case? ⃣ A. Lumbar sympathetic chains ⃣ B. Pelvic splanchnic nerves ⃣ C. Pudendal nerves ⃣ D. Sacral sympathetic chains ⃣ E. Vagus nerves
B. The visceral afferent innervation of the rectum is transmitted by way of the pelvic splanchnic nerves, which also provide the parasympathetic supply to this organ. The lumbar sympathetic chain receives sensory fi bers from the fundus and body of the uterus. The pudendal nerve provides origin for the inferior rectal nerve, the perineal nerve, and the dorsal nerve of the penis. The inferior rectal nerve supplies somatosensory fibers to the anal canal below the pectinate line and the perianal skin; the perineal nerve and dorsal nerve of the penis innervate structures of the urogenital region. The vagus nerve provides parasympathetic supply and afferent innervation (excluding pain) to the intestine proximal to the left colic fl exure. The lumbar and sacral sympathetic chains contribute sympathetic fi bers for innervation of smooth muscle and glands of certain pelvic viscera, but not sensory fi bers for the rectum.
A 42-year-old is female is admitted to the hospital due to blood in her stools. Physical examination reveals no signs of infl ammation, infection, or tumor. An endoscopic examination of the distal segment of the ileum reveals a lesion of the intestinal wall. Biopsy gives histologic evidence that the lesion contains gastric mucosa. Which of the following clinical conditions will most likely explain the symptoms and signs? ⃣ A. Internal hemorrhoids ⃣ B. External hemorrhoids ⃣ C. Diverticulosis ⃣ D. Meckel’s diverticulum ⃣ E. Borborygmi
D. Meckel diverticulum is a fi ngerlike projection of the ileum that is generally remembered by the “rule of 2s”: It occurs in about 2% of the population, is approximately 2 feet proximal from the ileocecal junction, is about 2 inches long, occurs 2 times as often in males as in females, may contain 2 types of ectopic tissue, and may be confused often with 2 different clinical conditions. The two types of ectopic tissue are gastric mucosa and pancreatic tissue. These, along with bleeding and pain, may give indications of peptic ulcer or appendicitis. Internal and external hemorrhoids involve the rectoanal area, not the ileum, in addition to which biopsy of hemorrhoids would not reveal the presence of gastric mucosa. Borborygmi are bowel sounds that occur with the passage of gas and bowel contents through the intestines. Diverticuloses are outpouchings of the colon and would therefore be lined with colic mucosa.
An 80-year-old male patient is admitted to the hospital with hypertension. His history includes a notation that he has had a poor appetite for some time. During physical examination it is observed that his blood pressure is 175/95 mm Hg and that he has a marked pulsation in his epigastric region. Which of the following diagnoses will most likely explain the symptoms and signs? ⃣ A. Hiatal hernia ⃣ B. Splenomegaly ⃣ C. Cirrhosis of the liver ⃣ D. Aortic aneurysm ⃣ E. Kidney stone
D. The aortic aneurysm often occurs between L3 and L4, below the bifurcation of the aorta, resulting in signifi cant increase in pressure, creating the marked abdominal pulsation. The remaining answer choices would be associated with referred pain and would not be likely to result in elevated blood pressure.
A 48-year-old female is admitted to the hospital with a distended abdomen. A CT scan examination provides evidence of the presence of ascites ( Fig. 3-1 ). In which of the following locations will an ultrasound machine most likely confi rm the presence of the ascitic fl uid with the patient in the supine position? ⃣ A. Subphrenic recess ⃣ B. Hepatorenal recess (pouch of Morison) ⃣ C. Rectouterine recess (pouch of Douglas) ⃣ D. Vesicouterine recess ⃣ E. Subhepatic recess
B. In a supine patient, fl uid accumulation will often occur in the pouch of Morison, which is the lowest space in the body in a supine position. The hepatorenal space is located behind the liver and in front of the parietal peritoneum covering the right kidney. The vesicouterine and rectouterine spaces are also potential areas of fl uid accumulation; however, fl uid accumulation in these spaces occurs when the patient is in an erect position rather than a supine position.
A 19-year-old male is admitted to the hospital after a violent automobile collision. An MRI examination reveals that the spinal cord has been transected at the L4 cord level. Which of the following portions of the intestine will most predictably lose parasympathetic innervation from the central nervous system? ⃣ A. Jejunum ⃣ B. Ascending colon ⃣ C. Ileum ⃣ D. Descending colon ⃣ E. Transverse colon
D. Descending colon. Below the left colic fl exure, innervation of the gastrointestinal tract is supplied by parasympathetic fi bers of the pelvic splanchnic nerves. The parasympathetic innervation of the midgut up to the descending colon is supplied by the vagus nerve. A hematoma occurring below L4 would affect innervation of the descending colon because the pelvic splanchnic nerves arise from spinal nerve levels S2 to S4. The jejunum, ascending colon, ileum, and transverse colon are all innervated by the vagus nerve.
A 55-year-old male is admitted to the hospital because of severe weight loss over the preceding 6-month period of time. Radiographic examination and other tests provide evidence that a tumor is causing portal hypertension. Laboratory studies reveal that the patient has fatty stool, malnutrition, and liver hypoxia. At which of the following locations is the tumor most likely located? ⃣ A. Right lobe of the liver ⃣ B. Left lobe of the liver ⃣ C. Porta hepatis ⃣ D. Falciform ligament ⃣ E. Hepatogastric ligament
C. The porta hepatis (transverse fi ssure of liver) transmits the proper hepatic artery, portal vein, common hepatic duct, autonomic nerves, and lymph vessels. A tumor in this region would be most detrimental because of its abundance of vessels and lymphatics that could lead to all of these symptoms when they are compromised functionally. A tumor in either the right or left lobes would not be as serious because it would not completely obstruct all of these vessels. The falciform ligament does not carry any vessels, so a tumor in this area would not lead to the symptoms described. The hepatogastric ligament is the bilaminar peritoneal connection between the liver and the lesser curvature of the stomach and is unrelated to the symptoms and signs here.
During a laparoscopic cholecystectomy on a 61-year-old male, which of the following arteries must be clamped to remove the gallbladder safely? ⃣ A. Common hepatic ⃣ B. Proper hepatic ⃣ C. Right hepatic ⃣ D. Left hepatic ⃣ E. Cystic
E. The cystic artery is the only artery listed that goes directly to the gallbladder. It is often a branch of the right hepatic artery and must be clamped before the gallbladder is cut free from its attachments. The common hepatic artery provides origin to the proper hepatic artery, which divides into right and left hepatic arteries supplying the liver, gallbladder, and biliary tree.
A 48-year-old male is admitted to the hospital with abdominal distension and pain. The radiographic image is shown in Fig. 3-2 . In which of the following locations will blood be detected with an ultrasound machine if the patient stands upright? ⃣ A. Subphrenic space ⃣ B. Hepatorenal space (pouch of Morison) ⃣ C. Rectouterine space (pouch of Douglas) ⃣ D. Rectovesical space ⃣ E. Subhepatic space
D. Fig. 3-2 is a CT scan that reveals an aortic aneurysm with hemorrhage. If the man stands in an erect position, the blood will be detected in the rectovesical space, which is a peritoneal recess between the bladder and the rectum in males. The subphrenic space is a peritoneal pouch between the diaphragm and the anterior and superior part of the liver. The hepatorenal space (pouch of Morison) is a deep peritoneal pocket between the posterior surface of the liver and the right kidney and suprarenal gland. The rectouterine space (pouch of Douglas) is a sac in females formed by a peritoneal-lined recess between the rectum and uterus. Although this is a logical answer choice, the rectouterine space is found only in women. The subhepatic space is between the liver and the transverse colon.
A 27-year-old woman is admitted to the emergency department with markedly elevated temperature and abdominal pain. Physical examination initially indicates paraumbilical pain, but the site of origin of pain soon shifts to the right lower quadrant. A CT scan is shown in Fig. 3-3 . Which of the following structures is affected? ⃣ A. Right ovary ⃣ B. Appendix ⃣ C. Iliocecal junction ⃣ D. Ascending colon ⃣ E. Ileum
B. Paraumbilical pain progressing into the right iliac fossa is a sign of appendicitis. The CT scan is one of an infl amed appendix. The structures in the scan that lie to the right of the vertebral body are part of the psoas muscle. Transverse section of this muscle signifi es that it is a cut from the lumbar region.
A 51-year-old complains of abdominal pain of 2-month duration. A CT scan of the patient’s abdomen is shown in Fig. 3-4 . An angiogram indicates that several arteries of the gastrointestinal tract are occluded due to atherosclerosis, producing bowel ischemia. Which of the following arteries is most likely occluded in the CT scan? ⃣ A. Middle colic ⃣ B. Right colic ⃣ C. Left colic ⃣ D. Iliocolic ⃣ E. Marginal
C. The arrows in the CT scan point to the descending colon. Therefore, the left colic artery, which supplies the descending colon, is the one most likely occluded in the CT scan. The middle colic, right colic, and ileocolic artery supply the ascending colon, and the marginal artery provides an anastomosis between branches of the superior mesenteric artery and inferior mesenteric artery.
A 53-year-old man visits the outpatient clinic because of an abnormal mass developing in his anal canal. An image from the physical examination is seen in Fig. 3-5 . A biopsy of the tissue reveals squamous cell carcinoma of the anus. Which of the following lymphatics will most typically fi rst receive cancerous cells from the anal tumor? ⃣ A. Deep inguinal lymph nodes ⃣ B. Superfi cial inguinal lymph nodes ⃣ C. Internal iliac nodes ⃣ D. External iliac nodes ⃣ E. Paraaortic nodes
The superfi cial inguinal lymph nodes are the fi rst drainage site for superfi cial perineal structures like the skin of the perianal region, prepuce of penis, scrotum, and anal canal inferior to the pectinate line. The superfi cial inguinal nodes also drain structures of the inferolateral quadrant of the trunk, including the anterior abdominal wall inferior to the umbilicus, gluteal region, and the lower limb. The deep inguinal lymph nodes drain the glans of the penis and the distal spongy urethra and receive drainage from the superfi cial inguinal lymph nodes. The common iliac nodes drain the external and internal iliac lymph nodes. The internal iliac lymph nodes drain inferior pelvic structures and deep perineal structures and receive drainage from the sacral nodes. The paraaortic nodes are the fi nal drainage site for all the above lymph nodes before they drain to the thoracic duct by way of the lumbar lymph trunks.
A 49-year-old man comes to the outpatient clinic with complaints of bloating, gas, and a sense of fullness for the preceding 2 years. A CT scan examination is shown in Fig. 3-6 . Which of the following structures is affected? ⃣ A. Spleen ⃣ B. Stomach ⃣ C. Duodenum ⃣ D. Pancreas ⃣ E. Descending colon
B. The white arrows in the CT scan in Fig. 3-6 point to the stomach. The spleen would not be in this CT slice because it is located more superiorly in the body than this section. Also, note that the psoas muscles are seen lying on the sides of the vertebral body, meaning that the section is in the lumbar region of the body. The duodenum is the structure located to the right of the stomach in the scan and is posterolateral to the aorta.
A 28-year-old female visits the outpatient clinic to receive the required physical examination for an insurance policy. Physical and laboratory examinations give evidence that she is probably a normal, healthy woman. A radiograph of the patient is shown in Fig. 3-7 . Which of the following is the most likely diagnosis? ⃣ A. Cholecystitis ⃣ B. Carcinoma of the liver ⃣ C. A caudal extension of the right hepatic lobe (Riedel lobe) ⃣ D. Pancreatic carcinoma ⃣ E. Carcinoma of the stomach
C. Because physical and laboratory tests show a normal, healthy woman, the anomaly of the radiograph would be expected to be benign. Riedel’s lobe is a normal variation of the liver, often an inferior extension of the right lobe of the liver, lateral to the gallbladder that extends about 4 or 5 cm below the rib cage. Carcinomas would present with abnormal laboratory examinations, and cholecystitis would present with an abnormal physical examination, as when the gallbladder is infl amed
A 35-year-old woman is admitted to the hospital with a mass protruding through her skin at the right lower quadrant. Physical examination reveals intestinal herniation, as shown in Fig. 3-8 . Which of the following is the most likely diagnosis? ⃣ A. Richter hernia ⃣ B. Spigelian hernia ⃣ C. Paraumbilical ⃣ D. Incisional hernia ⃣ E. Ventral hernia
B. A Spigelian hernia occurs along the semilunar line below the umbilical region and can protrude through the skin. A Richter hernia is a hernia that presents as a strangulated segment of part of the wall of an intestinal loop through any hernial opening. A paraumbilical hernia occurs at the level of the umbilicus, near the midline. An incisional hernia occurs with dehiscence (breakdown and reopening) of an operative incision after surgery. A ventral hernia is a type of incisional hernia located on the ventral surface of the abdomen, occurring only after surgery.
