Lab 26

Lumbosacral Trunk

- a large nerve, formed by the union of the fifth lumbar and first sacral nerves, which enters into the formation of the sacral plexus.

Renal Fascia

- a membranous condensation of extraperitoneal fascia that encloses the perirenal fat surrounding the kidney

Iliohypogastric Nerve

- a nerve that arises from the first lumbar nerve and supplies the abdominal muscles and the skin of the lower part of the anterior abdominal wall.

Ilioinguinal Nerve

- a nerve that arises from the first lumbar nerve, passes through the superficial inguinal ring, and supplies the skin of the upper medial thigh and of the scrotum or of the labia majora

Femoral Nerve definition

- a nerve that arises from the second, third, and fourth lumbar nerves and supplies the muscles and skin of the anterior region of the thigh.

Obturator Nerve

- a nerve that arises from the second, third, and fourth lumbar nerves in the psoas muscle, enters the thigh through the obturator canal, and supplies the muscles and skin on the medial side of the thigh.

Renal Vein

- any of the veins that accompany the renal arteries and open at right angles into the vena cava at the level of the second lumbar vertebra.

Sympathetic Trunk

- either of two long ganglionated nerve strands along the vertebral column that are connected to each spinal nerve by gray matter rami and that receive fibers from the spinal cord through white matter rami connecting with the thoracic and upper lumbar spinal nerves.

Which of the following is incorrect pertaining to the kidneys? A. The right kidney is related anteriorly to the liver, duodenum, and ascending colon. B. Extension of the hip joint may increase pain associated with kidney disease. C. The renal pelvis is the junction between the renal artery and the renal hilum. D. The left kidney is related anteriorly to stomach, spleen, pancreas, jejunum, and descending colon. E. Both kidneys are retroperitoneal.

C. The renal pelvis is the junction between the renal artery and the renal hilum.

Excessive distention of the ureter owing to a renal calculus (kidney stone) causes severe intermittent pain, ureteric colic, as it is gradually forced down the ureter by waves of contraction. The calculus may cause complete or intermittent obstruction of urinary flow. Depending on the level of obstruction, the pain may be referred to the lumbar (loin) or inguinal regions (groin), the proximal anterior aspect of the thigh, or the external genitalia and/or testis. The pain is referred to the cutaneous areas innervated by the spinal cord segments and sensory ganglia, which supply the ureter—mainly _____.

T11-L2

Sometimes the embryonic kidney on one or both sides fails to reach the abdomen and lies anterior to the sacrum. Although uncommon, awareness of the possibility of _______ should prevent it from being mistaken for a pelvic tumor and removed.

an ectopic pelvic kidney

In _______, part of the stomach and intestine herniate through a large posterolateral defect (foramen of Bochdalek) in the region of the lumbocostal trigone of the diaphragm (Fig. B2.11). Herniation almost always occurs on the left owing to the presence of the liver on the right. This type of hernia results from the complex development of the diaphragm.

congenital diaphragmatic hernia (CDH)

Section of a phrenic nerve in the neck results incomplete paralysis and eventual atrophy of the muscular part of the corresponding half of the _____, except in persons who have an accessory phrenic nerve. Paralysis of a _____ can be recognized radiographically by its permanent elevation and paradoxical movement.

diaphragm hemidiaphragm

The kidneys are close together in the embryonic pelvis. In approximately 1 in 600 fetuses, the inferior poles (rarely, the superior poles) of the kidneys fuse to form a _____. This U-shaped kidney usually lies at the level of the ___ vertebrae because the root of the *inferior mesenteric artery* prevented normal relocation of the kidneys. Horseshoe kidney usually produces no symptoms; however, associated abnormalities of the kidney and renal pelvis may be present, obstructing the ureter.

horseshoe kidney L3-L5

The site for the transplanted kidney is in the _____ of the greater pelvis (see Chapter 3), where it is firmly supported and where only short lengths of renal vessels and ureters are required for transplantation. The renal artery and vein are joined to the adjacent _____ , respectively; and the ureter is sutured into the nearby urinary bladder.

iliac fossa external iliac artery and vein

A nonmuscular area of variable size called the ______ usually occurs between the costal and lumbar parts of the diaphragm. This part of the diaphragm is normally formed only by fusion of the superior and inferior fascias of the diaphragm. When a traumatic diaphragmatic hernia occurs, the stomach, small intestine and mesentery, transverse colon, and spleen may herniate through this area into the thorax.

lumbocostal triangle

While you are assisting in an open lower abdominal surgery, the surgeon points out a nerve running along the medial anterior surface of the psoas major muscle. The surgeon points out that, injury to or entrapment of this nerve postoperatively, is a well-known complication of abdominal surgery. This nerve is most likely which of the following? A. Ilioinguinal B. Genitofemoral C. Lumbosacral trunk D. Obturator E. Femoral

B. Genitofemoral The genitofemoral nerve emerges through the psoas major muscles and runs directly along its anterior surface.

The ilioinguinal and iliohypogastric nerves: A. together form the lumbosacral trunk. B. are both L1 ventral rami. C. supply the adductor muscles of the thigh. D. innervate the psoas muscle. E. pass posterior to the quadratus lumborum.

B. are both L1 ventral rami.

A positive psoas sign: A. could indicate liver cancer. B. could indicate pancreatitis. C. indicates a normal psoas reflex. D. means that the psoas muscle is normal in strength. E. means that the thigh can be extended more than 30 degrees.

B. could indicate pancreatitis.

A 78-year-old man is suffering from ischemia of the suprarenal glands. This condition results from rapid occlusion of direct branches of which of the following arteries? A. Superior mesenteric, inferior mesenteric and renal arteries B. Aorta, splenic, and inferior phrenic arteries C. Aorta, inferior phrenic and renal arteries D. Renal, splenic, and inferior mesenteric arteries E. Aorta and hepatic and renal arteries

C. Aorta, inferior phrenic and renal arteries The suprarenal gland receives arteries from three sources. The superior suprarenal artery arises from the inferior phrenic artery, the middle suprarenal artery arises from the abdominal aorta, and the inferior suprarenal artery arises from the renal artery. The hepatic, superior mesenteric, inferior mesenteric and splenic arteries do not supply the suprarenal gland.

Renal Capsule

- the investing tissue around the kidney, divided into the fibrous renal capsule and the adipose renal capsule.

Subcostal Nerve

- the ventral branch of the 12th thoracic nerve, supplying parts of the abdominal muscles and giving off cutaneous branches to the skin of the lower abdominal wall and to the gluteal region.

Lateral Cutaneous Nerve of Thigh

-a nerve that arises from the second and third lumbar nerves and supplies the skin of the anterolateral and lateral surfaces of the thigh.

The suprarenal glands: A. receive sympathetic innervation via the lumbar splanchnic nerves. B. are each supplied by one artery that arises from a renal artery. C. each receive blood from and drain directly into the kidney. D. are each supplied by one artery that arises from the abdominal aorta. E. are typically each drained by one vein.

E. are typically each drained by one vein.

An abscess resulting from tuberculosis in the lumbar region tends to spread from the vertebrae into the psoas sheath, where it produces a _____. As a consequence, the psoas fascia thickens to form a strong stocking-like tube. Pus from the this condition passes inferiorly along the psoas within this fascial tube over the pelvic brim and deep to the inguinal ligament. The pus usually surfaces in the superior part of the thigh. Pus can also reach the psoas sheath by passing from the posterior mediastinum when the thoracic vertebrae are diseased.

psoas abscess

In ______, waste products such as urea accumulate in the blood and tissues and ultimately reach fatal levels. Peritoneal dialysis may be performed, in which soluble substances and excess water are removed from the system by transfer across the peritoneum, using a dilute sterile solution that is introduced into the peritoneal cavity on one side and then drained from the other side. Diffusible solutes and water are transferred between the blood and the peritoneal cavity as a result of concentration gradients between the two fluid compartments. Peritoneal dialysis is usually employed only temporarily; however, for the long term it is preferable to use direct blood flow through a renal dialysis machine.

renal failure

Rupture of the diaphragm and herniation of viscera can result from a sudden large increase in either the intrathoracic or intra-abdominal pressure. The common cause of this injury is _________. Most diaphragmatic ruptures are on the left side (95%) because the substantial mass of the liver, intimately associated with the diaphragm on the right side, provides a physical barrier.

severe trauma to the thorax or abdomen during a motor vehicle accident

Ureteric calculi can be observed and removed with a _______. Another technique, lithotripsy, focuses a shock wave through the body that breaks the stones into fragments, which then pass with the urine.

nephroscope

The _____ is a semipermeable membrane with an extensive surface area, much of which (subdiaphragmatic portions in particular) overlies blood and lymphatic capillary beds.

peritoneum

The Suprarenal Veins are two in number: The right ends in the ___. The left ends in the ___.

inferior vena cava. left renal or left inferior phrenic vein.

Fluid injected into the peritoneal cavity is absorbed rapidly. For this reason, anesthetic agents, such as solutions of barbiturate compounds, may be injected into the peritoneal cavity by _____.

intraperitoneal injection.

Ovarian Vessels

- An artery with its origin in the aorta, with distribution to the ureter, ovary, ovarian ligament, and uterine tube, and with anastomosis to the uterine artery.

During their "ascent" to their final site, the embryonic kidneys receive their blood supply and venous drainage from successively more superior vessels. Usually, the inferior vessels degenerate as superior ones take over the blood supply and venous drainage. Failure of some of these vessels to degenerate results in _____ renal arteries and veins. Variations in the number and position of these vessels occur in about 25% of people.

accessory (or polar)

Bifid renal pelvis and ureter are fairly common. These anomalies result from division of the _______, the primordium of the renal pelvis and ureter. The extent of ureteral duplication depends on the completeness of embryonic division of it. The bifid renal pelvis and/or ureter may be unilateral or bilateral; however, separate openings into the bladder are uncommon. Incomplete division of it results in a bifid ureter; complete division results in a _____.

metanephric diverticulum (ureteric bud) supernumerary kidney.

In anticipation for a medical school swimming party, a 60-year-old male professor squeezes into last year's bikini bathing suit despite gaining 25 lbs. over the winter. Following a day of "impressing" his students and colleagues, he notices numbness, tingling, and a burning sensation in the lateral aspect of his left upper thigh. His symptoms are exacerbated by applying pressure near the left anterior superior iliac spine. What nerve is most likely affected? A. Lateral femoral cutaneous nerve B. Femoral branch of genitofemoral nerve C. Iliohypogastric nerve D. Anterior cutaneous branches of femoral nerve E. Ilioinguinal nerve

A. Lateral femoral cutaneous nerve The answer is lateral femoral cutaneous nerve. This misguided professor presents with classic signs and symptoms of entrapment of the lateral femoral cutaneous nerve, which passes under the inguinal ligament in proximity to the anterior superior iliac spine, demonstrated in the given figure. Impingement of the lateral femoral cutaneous nerve is called meralgia paresthetica or bikini brief syndrome and results in abnormal sensations of burning, pain, and numbness in the lateral portion of the upper thigh. In the case of this progressive professor, his fashionable swimwear compressed the lateral femoral cutaneous nerve near the anterior superior iliac spine. Moreover, meralgia paresthetica is seen in individuals who have gained considerable weight (e.g., pregnancy) in a short period. Femoral branch of the genitofemoral nerve is incorrect. The femoral branch of the genitofemoral nerve is formed by the anterior rami of the L1-2 spinal nerves. This nerve supplies the upper medial aspects of the thigh. Due to the location of the patient's symptoms in the lateral aspect of his left upper thigh, this nerve is not involved. Anterior cutaneous branches of femoral nerve is incorrect. The anterior cutaneous branches of femoral nerve supply the upper medial aspect of the thigh. These nerves are derived from L2-4, and they are located too medial to elicit the symptoms in this fashion-conscious professor. Ilioinguinal nerve is incorrect. The ilioinguinal nerve arises from the lumbar plexus from the anterior ramus of the L1 spinal nerve. This nerve supplies the upper medial aspects of the thigh and gives off the anterior scrotal nerves involved in the afferent limb of the cremasteric reflex. Due to the location of the patient's symptoms in the lateral aspect of his left upper thigh, this nerve is not involved. Iliohypogastric nerve is incorrect. The iliohypogastric nerve arises primarily from the ventral ramus of L1, with possible contributions from T12. This nerve runs above the anterior superior iliac spine within the anterolateral muscular wall of the abdomen. However, if this nerve were involved, the abnormal sensations would have been located in the suprapubic region of the abdomen.

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? A. Left colic flexure B. Duodenojejunal junction C. Right colic flexure D. Ileocecal junction

A. Left colic flexure The vagus nerve supplies parasympathetic nerve fibers to the 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 incorrect. 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.

A 47-year-old woman was found curled up in bed, crying because of excruciating pain. She was rushed to the emergency department. The physician asked her to explain how the pain felt. She said it was extreme and came in waves. She showed with her finger that the pain extended from her right side (loin) to her groin (lateral to pubic region). An AP radiograph revealed a renal calculus (kidney stone) in her right ureter. Which of the following statements correctly describes the most likely cause of the waves of pain that passed obliquely across the patient's abdomen? A. Painful spasms of the smooth muscle in the wall of the ureter occur as the calculus moves inferomedially from the loin to the groin. B. The excruciating pain occurred when the calculus passed through the ureteric orifice into the urinary bladder. C. The calculus stretches the parietal peritoneum on the posterior abdominal wall as it passes through the ureter. D. Afferent nerve fibers from the ureter pass to spinal cord segments T8 and T9, and the pain is referred to the skin areas supplied by these segments.

A. Painful spasms of the smooth muscle in the wall of the ureter occur as the calculus moves inferomedially from the loin to the groin. The answer is painful spasms of the smooth muscle in the wall of the ureter occur as the calculus moves inferomedially from the loin to the groin. Because the calculus is larger than the lumen of the ureter and has sharp and abrasive surfaces, it causes pain as it passes through it (ureteric colic). Afferent sensory nerves enter the spinal cord at the T11-T12 and L1-L2 segments. The pain is referred to the skin areas that are supplied by these segments (loin and groin). The calculus stretches the parietal peritoneum on the posterior abdominal wall as it passes through the ureter is incorrect. Although the ureter adheres closely to the parietal peritoneum, passage of the calculus along the ureter would not stretch the peritoneum enough to cause severe pain. The excruciating pain occurred when the calculus passed through the ureteric orifice into the urinary bladder is incorrect. The severe pain occurs before the calculus enters the bladder, although tenderness along the course of the ureter may persist for some time. However, because the intramural part is one of the three areas of normal ureteric constriction, it is a site where calculi often get trapped, which is very painful. Afferent nerve fibers from the ureter pass to spinal cord segments T8 and T9, and the pain is referred to the skin areas supplied by these segments is incorrect. The ureter sends afferent nerves to T11-L2 spinal cord segments. The pain from around her labia is carried by the lateral cutaneous nerve of the thigh. It is carried by the genitofemoral nerve.

Because of a lesion, the parasympathetic nerve fibers are unable to induce a contraction of the detrusor muscle and relaxation of the internal sphincter. The injured parasympathetic fibers that supply the urinary bladder are derived from which of following nerves? A. Pelvic splanchnic nerve B. Greater splanchnic nerve C. Lesser splanchnic nerve D. Vagus nerve E. Sacral splanchnic nerve

A. Pelvic splanchnic nerve The answer is the pelvic splanchnic nerves. The urinary bladder receives parasympathetic fibers from the pelvic splanchnic nerve, not the vagus nerve. The greater, lesser, lumbar, and sacral splanchnic nerves contain sympathetic preganglionic fibers.

You see a female patient in the emergency room with severe, intermittent "loin" (lumbar region) pain who is also having great difficulty urinating. Your most likely first diagnosis is: A. ureteric calculus. B. ectopic pregnancy. C. ureteric ischemia. D. kidney disease. E. ruptured renal artery.

A. ureteric calculus.

In renal transplantation the: A. kidney is sutured to the diaphragm to maintain its position. B. transplanted ureter is sutured to the patient's ureter. C. kidney is placed in the iliac fossa of the greater pelvis. D. suprarenal gland is transplanted with the kidney. E. renal artery and vein are sutured to the aorta and inferior vena cava, respectively.

C. kidney is placed in the iliac fossa of the greater pelvis.

Lesion of the genitofemoral nerve will have the greatest affect on what action? A. Guarding reflex B. Hip flexion C. Wrinkling of the scrotum D. Elevation of the testes E. Coughing

D. Elevation of the testes The genital branch of the genitofemoral nerve innervates the cremaster muscle, which is responsible for reflexive elevation of the testes.

Which of the following is incorrect pertaining to the celiac plexus? A. It contains both sympathetic and parasympathetic fibers. B. It supplies the gallbladder. C. It surrounds the root of the celiac arterial trunk. D. It supplies the descending colon. E. It supplies the stomach.

D. It supplies the descending colon.

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 IVC just proximal to the entrance of the renal vein. This venous blockage may result in dilation of which of the following veins? A. Right hepatic vein B. Right inferior phrenic vein C. Portal vein D. Left suprarenal vein E. Left gastric vein

D. Left suprarenal vein The answer is left suprarenal 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 IVC above the obstruction. The left gastric vein joins the portal vein, which enters the liver.

Which of the following is incorrect pertaining to the diaphragm? A. Its crura attach to the inferior six costal cartilages. B. It is at its most superior level when a person is supine. C. Its central tendon is in contact with the fibrous pericardium. D. Irritation of the diaphragmatic pleura can result in pain that is referred to the shoulder. E. It is partially supplied with blood via branches of the internal thoracic artery.

Its crura attach to the inferior six costal cartilages.

An infant is born with a large defect in the central tendon of the diaphragm. This condition is most likely the result of malformation of which of the following structures? A. Cervical somites B. Pleuroperitoneal folds C. Ventral mesentery of the gut tube D. Septum transversum E. Dorsal mesentery of the esophagus

D. Septum transversum The answer is septum transversum. The central tendon of the diaphragm is the expansive tendinous area into which the diaphragmatic muscle inserts and acts upon to produce respiratory movements. Also, it provides passage of the inferior vena cava, which traverses the diaphragm at the 8th thoracic (T8) vertebral level. The central tendon is formed from the embryonic septum transversum. The initial intraembryonic coelom is a single continuous area spanning the length of the trunk. Formation of the diaphragm separates the thoracic and peritoneal cavities. The diaphragm forms from fusion of tissues that originate from four different sources: septum transversum, paired pleuroperitoneal membranes, dorsal mesentery of the esophagus, and cervical somites. The septum transversum is a mesodermal wall that forms between the primitive heart tube and developing liver. It forms most of the diaphragm. Dorsal mesentery of the esophagus is incorrect. This portion of the dorsal mesentery of the gut tube forms the crura of the diaphragm. These muscular legs attach the diaphragm to the vertebral column and form the margins of the aortic hiatus. Additionally, the right crus forms the esophageal hiatus. Ventral mesentery of the gut tube is incorrect. The ventral mesentery of the gut tube is not related to formation of the diaphragm. It gives rise to the lesser omentum, falciform ligament, and the coronary and triangular ligaments of the liver. Pleuroperitoneal folds is incorrect. The paired pleuroperitoneal folds are extensions from the posterolateral body wall. They form much of the posterolateral aspect of the diaphragm that is not derived from the septum transversum or the dorsal esophageal mesentery. Cervical somites is incorrect. The septum transversum is initially located along cervical somites and spinal cord segments C3-5. Differential rates of body growth between the trunk and internal organs cause shifting and repositioning of the diaphragm to its final thoracolumbar position. However, myoblasts from the cervical somites invade the initial diaphragmatic folds and form the muscular parts of the diaphragm. Further, the cervical spinal cord segments give rise to the phrenic nerves that provide motor innervation to the diaphragm.

A 60-year-old man is diagnosed with a posterior abdominal wall tumor that is causing lesions in the superior mesenteric plexus. Which of the following pathways is most likely affected? A. Venous drainage from the transverse colon B. Visceral afferents from the proximal duodenum C. Lymph drainage from the liver D. Sympathetic supply to the ascending colon E. Parasympathetic supply to the posterior aspect of the stomach

D. The answer is sympathetic supply to the ascending colon. The superior mesenteric plexus (ganglia) is an autonomic network around the base of the superior mesenteric artery. Presynaptic sympathetic fibers synapse at this location, and postsynaptic sympathetic fibers follow branches of this artery to distribute to the midgut organs, including the ascending colon. Presynaptic parasympathetic fibers from the vagus nerve and visceral afferents also pass through this plexus en route to and from the midgut. Parasympathetic supply to the posterior aspect of the stomach is incorrect. Parasympathetic supply to the posterior stomach is derived directly from the posterior (right) vagus nerve as it descends from the esophagus. Further parasympathetic distribution to the foregut runs mainly from the posterior vagus through the celiac plexus and follows the celiac arterial axis. Lymph drainage from the liver is incorrect. Lymphatic drainage of the abdominopelvic organs mainly parallels the arterial supply to those organs, so lymphatic drainage of the liver flows toward the celiac nodes. Lymph drainage from the midgut organs flows to the superior mesenteric nodes, where it could be affected by a tumor invading this area. Venous drainage from the transverse colon is incorrect. The transverse colon is mostly related to midgut origins. However, venous drainage of the gut tube is primarily into the hepatic portal system rather than directly into systemic veins. Thus, most of the gut tube drains into the liver via the portal vein. Visceral afferents from the proximal duodenum is incorrect. The visceral afferents from the foregut and midgut regions mainly parallel the sympathetic supply to those organs. Thus, afferents from the proximal duodenum pass mainly through the celiac ganglia.

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: A. The left kidney lies a bit lower than the right one. B. The right renal artery is shorter than the left renal artery. C. The perirenal fat lies external to the renal fascia. D. The left renal vein runs anterior to both the aorta and the left renal artery. E. The renal fascia does not surround the suprarenal gland.

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

_______, a protrusion of part of the stomach into the thorax through the esophageal hiatus, was discussed earlier in this chapter. The structures that pass through the esophageal hiatus (vagal trunks, left inferior phrenic vessels, esophageal branches of the left gastric vessels) may be injured in surgical procedures on the esophageal hiatus (e.g., repair of a hiatus hernia).

Hiatal or hiatus hernia

The medulla of the suprarenal glands secretes the catecholamines epinephrine and norepinephrine into the blood stream. Which of the following is correct regarding the vascular supply of the suprarenal glands? A. The left suprarenal gland is supplied by a single suprarenal branch of the left renal artery. B. The right suprarenal gland drains via a single suprarenal vein into the right renal vein. C. The left suprarenal gland drains via a single suprarenal vein into the inferior vena cava. D. The right suprarenal gland is supplied by a suprarenal branch of the common hepatic artery. E. Each suprarenal gland is supplied by branches of the inferior phrenic artery, aorta, and renal artery.

The answer is each suprarenal gland is supplied by branches of the inferior phrenic artery, aorta, and renal artery. Each suprarenal gland is normally supplied by three suprarenal arteries. These vessels are branches of the inferior phrenic artery, aorta, and renal artery. Each suprarenal gland is normally supplied by the three suprarenal arteries. The right suprarenal gland drains via a single suprarenal vein directly into the inferior vena cava. The left suprarenal gland drains via a single suprarenal vein into the left renal vein.

In a patient with an extensive knife wound to the lower back, the thoracolumbar fascia is seriously compromised. Which of the following is not true of this fascia? A. It attaches to the iliac crest B. It attaches to the latissimus dorsi C. It has anterior and posterior layers D. It encloses the kidney E. It forms the lateral arcuate ligament

The answer is it encloses the kidney. The thoracolumbar fascia encloses the muscles of the posterior abdominal wall, and attaches to the latissimus dorsi. It does not enclose the kidney

A 60-year-old man is diagnosed with a posterior abdominal wall tumor that is causing lesions in the superior mesenteric plexus. Which of the following pathways is most likely affected? A. Visceral afferents from the proximal duodenum B. Parasympathetic supply to the posterior aspect of the stomach C. Lymph drainage from the liver D. Venous drainage from the transverse colon E. Sympathetic supply to the ascending colon

The answer is sympathetic supply to the ascending colon. The superior mesenteric plexus (ganglia) is an autonomic network around the base of the superior mesenteric artery. Presynaptic sympathetic fibers synapse at this location, and postsynaptic sympathetic fibers follow branches of this artery to distribute to the midgut organs, including the ascending colon. Presynaptic parasympathetic fibers from the vagus nerve and visceral afferents also pass through this plexus en route to and from the midgut. Parasympathetic supply to the posterior aspect of the stomach is incorrect. Parasympathetic supply to the posterior stomach is derived directly from the posterior (right) vagus nerve as it descends from the esophagus. Further parasympathetic distribution to the foregut runs mainly from the posterior vagus through the celiac plexus and follows the celiac arterial axis. Lymph drainage from the liver is incorrect. Lymphatic drainage of the abdominopelvic organs mainly parallels the arterial supply to those organs, so lymphatic drainage of the liver flows toward the celiac nodes. Lymph drainage from the midgut organs flows to the superior mesenteric nodes, where it could be affected by a tumor invading this area. Venous drainage from the transverse colon is incorrect. The transverse colon is mostly related to midgut origins. However, venous drainage of the gut tube is primarily into the hepatic portal system rather than directly into systemic veins. Thus, most of the gut tube drains into the liver via the portal vein. Visceral afferents from the proximal duodenum is incorrect. The visceral afferents from the foregut and midgut regions mainly parallel the sympathetic supply to those organs. Thus, afferents from the proximal duodenum pass mainly through the celiac ganglia.

Perinephric Abscess

The attachments of the renal fascia determine the path of extension of a perinephric abscess. For example, the fascia at the renal hilum firmly attaches to the renal vessels and ureter, usually preventing spread of pus to the contralateral side. However, pus from an abscess (or blood from an injured kidney) may force its way into the pelvis between the loosely attached anterior and posterior layers of the pelvic fascia.

The iliopsoas muscle has extensive and clinically important relations to the kidneys, ureters, cecum, appendix, sigmoid colon, pancreas, lumbar lymph nodes, and nerves of the posterior abdominal wall. When any of these structures is diseased, movement of the iliopsoas usually causes pain. When intra-abdominal inflammation is suspected, the iliopsoas test is performed. The person is asked to lie on the unaffected side and to extend the thigh on the affected side against the resistance of the examiner's hand. Pain resulting from this maneuver is a positive psoas sign. An acutely inflamed ____, for example, will produce a positive sign.

appendix

Pain from the diaphragm radiates to two different areas because of the difference in the sensory nerve supply of the diaphragm. Pain resulting from irritation of the diaphragmatic pleura or the diaphragmatic peritoneum is referred to the ____. These segments also contribute anterior rami to the phrenic nerves. Irritation of peripheral regions of the diaphragm, innervated by the ______, is more localized, being referred to the skin over the costal margins of the anterolateral abdominal wall.

shoulder region, the area of skin supplied by the C3-C5 segments of the spinal cord inferior intercostal nerves