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iv q1 - - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 1 (https://www.usmleforum.com/forumdisplay.php?fid=2) +--- Thread: iv q1 - (/showthread.php?tid=20098) |
iv q1 - - ArchivalUser - 08-18-2004 jaf A 36-year-old man presents to his physician complaining of right scrotal swelling. He states that the swelling has been present for 1 week. He initially noticed the swelling shortly after moving furniture for his new living room. He denies any nausea, vomiting, change in bowel habits, abdominal pain, or urinary tract symptoms. He has no other significant medical or surgical history. On examination, he has an enlarged right hemi-scrotum with a mass that appears to be originating at the level of the external inguinal ring. With the patient completely relaxed, the physician is able to reduce the mass by pushing it back through the external inguinal ring. With the mass reduced, the physician instructs the patient to perform a Valsalva maneuver, upon which a protrusion is felt at the external inguinal ring. Once the mass is reduced, the testicle appears normal in size and consistency. Question 1 of 4 Which of the following is the most likely diagnosis? A. Hydrocele B. Femoral hernia C. Inguinal hernia D. Testicular cancer E. Varicocele Question 2 of 4 Which of the following nerves travels along the spermatic cord within the inguinal canal and may be damaged during a surgical procedure to correct this patient's condition? A. IIiohypogastric B. IIioinguinal C. Lateral femoral cutaneous D. Obturator E. Pudendal Question 3 of 4 If a segment of terminal ileum becomes strangulated as a consequence of his condition, it may become infarcted and necrotic due to occlusion of a branch of which of the following vessels? A. Celiac trunk B. Inferior mesenteric artery C. Middle colic artery D. Right colic artery E. Superior mesenteric artery Question 4 of 4 Which of the following pathological processes might cause the patient's underlying condition to occur in an infant? A. Defect in the floor of the inguinal canal B. Defect in the internal inguinal ring C. Defect in the linea semilunaris D. Patent processus vaginalis E. Persistent lumen of the tunica vaginalis 0 - ArchivalUser - 08-18-2004 jaf 1.1 The correct answer is C. This patient has a reducible inguinal hernia. A hernia is a protrusion of a structure, usually intestine, through tissue that normally contains it. Inguinal hernias are either direct or indirect. Indirect inguinal hernias occur through the internal inguinal ring in a protrusion of peritoneum along the spermatic cord in the internal spermatic fascia. Direct inguinal hernias occur through the floor of the inguinal canal, separate from the spermatic cord as a result of breakdown of the transversus abdominis aponeurosis and transversalis fascia. If the mass, i.e., hernia, is easily returned back to its normal position, then it is called reducible. If the mass is not reducible, then this is called incarcerated. And, if the mass becomes incarcerated and develops compromised blood supply, it is termed strangulated. Strangulated hernias require emergent repair because the intestinal contents will necrose and cause the patient to become sick. As long as the mass is reducible, surgical repair can be performed on an outpatient basis. 1.2 The correct answer is B. Although it is now possible to perform inguinal hernia repairs laparoscopically, the traditional approach is through an incision over the inguinal canal. At the time of surgery, the inguinal canal is opened via sharp dissection through the external oblique aponeurosis (the anterior wall of the inguinal canal). The ilioinguinal nerve is then encountered as it runs on the anterior aspect of the spermatic cord. If not properly identified at time of surgery it is possible to transect the ilioinguinal nerve or to "trap" it during closure. If the ilioinguinal nerve is transected or entrapped in closure, the patient will complain of numbness over the nerve's distribution, i.e., the upper medial aspect of the thigh and the anterior portion of the scrotum on the affected side. The iliohypogastric, lateral femoral cutaneous, obturator, and pudendal nerves are not encountered during traditional inguinal hernia repair. 1.3 The correct answer is E. The small bowel is a derivative of the midgut and therefore receives its blood supply from the superior mesenteric artery. This artery emerges from the aorta 1 cm below the celiac trunk and passes ventral to the left renal vein to give off 12 to 15 jejunal and ileal arteries. As these arteries divide, they join with an adjacent branch to form arches. These arches may then communicate to form an arcade. Straight arteries also emerge from these arches to supply the bowel. Although there are variants, the ileal artery is usually a branch of the superior mesenteric artery, which supplies a branch to the terminal ileum. 1.4 The correct answer is D. The pathologic process that causes hernias is different in neonates and infants than in an adult. Embryologically, in the seventh week, the testes begin descending from their location at the 10th thoracic level into the scrotum. After the eighth week, a peritoneal evagination called the processus vaginalis forms just anterior to the gubernaculum. The gubernaculum is a condensation of peritoneum that attaches superiorly to the gonad and inferiorly to the fascia that is developing between the external and internal oblique muscles in the region of the labioscrotal swellings. The processus vaginalis pushes out as a "sock-like" extension into the transversalis fascia, the internal oblique muscle, and the external oblique muscle, thus forming the inguinal canal. After the processus vaginalis has evaginated into the scrotum, the gubernacula shorten and simply pull the gonads through the canal. Within the first year after birth, the superior portion of the processus vaginalis is usually obliterated, leaving only a distal remnant sac, the tunica vaginalis, which lies anterior to the testis. During infancy, this sac wraps around most of the testis. Its lumen is normally collapsed, but under pathologic conditions it may fill with serous secretions, forming a testicular hydrocele (choice E). If the processus vaginalis r |