1.
The most important measurement of the pelvic outlet, indicating the SMALLEST dimension, is the transverse midplane diameter. It is measured between which of the following?
Correct Answer
A. Ischial spines
Explanation
(Moore and Dalley, pp 362–363.) The transverse midplane diameter is measured between the ischial spines. It can be approximated by the somewhat greater transverse diameter measured between the ischial tuberosities (answer b). The distance from the lower margin of the pubic symphysis to the sacroiliac joint (answer c) defines the sagittal diameter, which is usually the greatest dimension and, therefore, unimportant. The measurement from the sacral promontory to the inferior margin of the pubic symphysis (answer d) is the diagonal conjugate, an estimate of the pelvic inlet
2.
At delivery, caudal analgesia is induced by administration of anesthetic into the epidural space in the sacral region. The needle is introduced via which of the following?
Correct Answer
E. Sacral hiatus
Explanation
(Moore and Dalley, pp 422–424, 493.) Caudal analgesia can be induced by an injection of anesthetic through the sacral hiatus into the sacral epidural space of the vertebral canal well caudal to the termination of the dural sac (answer b). The sacral hiatus represents the absence of a complete neural arch of the fifth sacral vertebra. The four anterior (answer a) and posterior (answer d) sacral foramina on either side of the midline join the intervertebral foramen (answer c) and provide egress for the anterior and posterior primary rami of the sacral spinal nerves. The level to which the anesthesia blocks the spinal nerves is a function of the amount of anesthetic delivered.
3.
Which structure is most susceptible to unintentional damage during a hysterectomy?
Correct Answer
B. Ureter
Explanation
(Moore and Dalley, pp 387–388.) The uterine artery (answer a) crosses anterior and superior to the ureter near the lateral fornix of the vagina and is deliberately clamped and removed during a hysterectomy. Some clinicians and anatomists once referred to the uterine artery as “the bridge over troubled waters.” Because of its close proximity to the artery, the ureter may be accidentally ligated or severed while tying off of the artery. Of course, the bladder (answer c) and the kidney (answer e) are large structures and should not be mistakenly clamped. The urethra (answer d) should be far out of the operating field.
4.
The patient is a 45-year-old man with a history of colonic diverticulosis. He complains of fever with pain and swelling in the rectal area. You are concerned that the colonic diverticulum may have become infected (diverticulitis) and ruptured into the space indicated by the asterisk in this CT scan. Which of the following is correct regarding the space indicated by the red asterix?
Correct Answer
D. Pus from the abscessed diverticuli in that space can extend anteriorly deep to
the perineal membrane, but inferior to the urogenital diapHragm
Explanation
(Moore and Dalley, pp 449–451.) Pus from the abscessed diverticuli in that space can extend anteriorly deep to the perineal membrane, but inferior to the urogenital diaphragm. The ischioanal fossa (asterisk on CT accompanying the question) is a fat-filled space [thus not muscle (answer b)] that extends from below the levator ani muscle (puborectalis, pubococcygeus, and iliococcygeus muscles). It also extends anteriorly in the area between the pelvic diaphragm (superiorly) and the perineal membrane (inferiorly). It cannot extend superiorly above the pelvic diaphragm [thus not (answer c)] and, therefore, cannot extend superiorly anterior to the sacrum (answer d). The paracolic gutter (answer a) in not on the image.
5.
Which of the following arteries may occasionally arise as a branch of
the external iliac artery or inferior epigastric artery instead of as a branch of
the internal iliac artery?
Correct Answer
B. Obturator artery
Explanation
Moore and Dalley, p 387.) The obturator usually arises from the anterior trunk of the internal iliac artery. However, in 25% of the population, it arises from the inferior epigastric or the external iliac artery. There is considerable variation as to the origins of the branches of the posterior and anterior trunks of the internal iliac artery. The internal pudendal artery (answer a), umbilical artery (answer d), and uterine artery (answer e) almost always arise from the anterior trunk. The superior
gluteal artery (answer c) usually arises from the posterior trunk.
6.
A couple comes to your office because they have been unable to conceive a child after 1 year of trying. You examine the man and notice a darkish mass and fullness of the left scrotum/spermatic cord compared to the smaller right scrotum/spermatic cord. You suggest he follow up with an urologist because you suspect which of the following?
Correct Answer
B. Acquired varicocele
Explanation
(Moore and Dalley, pp 228–229.) A dark mass within the scrotum would most likely be one of two things: varicocele or indirect inguinal hernia. Varicoceles are a stasis of blood within the
pampiniform plexus and occur most frequently on the left side because the testicular vein on the left drains into the higher pressure left renal vein, whereas the right testicular vein drains into the inferior vena cava. The presence of a varicocele is associated with reduced fertility. A femoral hernia (answers c and d) would not end up in the scrotum, rather within the thigh. Cryptorchidism (answer a), that is an undescended testicle, on the right side does not fit the physical examination findings. The right side is
normal [thus not (answer e)].
7.
Which of the following is one of the roles of the sympathetic chain in the pelvis?
Correct Answer
B. Cutaneous function (sudomotor, vasomotor, pilomotor)
Explanation
(Moore and Dalley, pp 399, 425, 432.) Postsynaptic sympathetic neurons destined for the skin lie in the ganglia of the sympathetic chain. Although the preganglionic fibers arise between T1 and L2, each of the sacral ganglia has a gray ramus that brings postganglionic fibers to the associated spinal nerve. These sympathetic neurons mediate sweating (sudomotor), vasoconstriction (vasomotor), and piloerection (pilomotor) in dermatomes S1–S5. Male ejaculation is practically mediated by skeletal muscle (contraction of the bulbospongiosus muscle innervated by superficial perineal nerves, branches of the pudendal nerve.) Ejaculation also requires sympathetic discharge to keep the internal urethral sphincter closed, preventing so called retroejaculation into the bladder. Emission (rapid contraction of the vas deferens) is mainly mediated by sympathetic, but mainly by lumbar splanchnic nerves, thereby bypassing the sympathetic chain ganglia. Erection in both male and female (answers c and d)
is mainly mediated by parasympathetic nerves. Bladder contraction (answer a) is also mainly controlled by parasympathetic nerves.
8.
Both the autonomic and vascular systems need to function properly for successful male sexual function. Which of the following statements concerning erection, emission, and ejaculation in the male is correct?
Correct Answer
E. Contraction of the bulbospongiosus muscles impedes the drainage of blood from the corpus spongiosum
Explanation
(Moore and Dalley, p 449.) The bulbospongiosus muscle is innervated by the pudendal nerve (S2–S4) and its contraction helps to keep blood within the shaft of the penis. Contraction of the internal urethral sphincter is under control of the sympathetic nervous system [thus not (answer a)]. Concomitant with dilation of the helicine arteries under parasympathetic innervation [thus not (answers b and c)], which allows increased blood to flow into the cavernous spaces, contraction of the bulbospongiosus and ischiocavernosus muscles at the base of the cavernous bodies reduce blood from leaving, resulting in engorgement and penile or clitoral erection. Emission of seminal fluid, prostatic secretions, and sperm from the vas deferens is due to contraction of smooth muscle under sympathetic
control [thus not (answer d)].
9.
A 45-year-old man was riding a snowmobile and hit a snow-covered rocky outcropping. When standing for the first time after the accident, he slipped and fell on the outcropping and now is experiencing pain in the gluteal region. In this CT scan, the dark linear structure indicated by the arrow
is which of the following?
Correct Answer
B. The sacrococcygeal joint
Explanation
. (Moore and Dalley, pp 359–360.) The sacrococcygeal joint. The indicated line represents the sacroiliac joint. These structures are seen bilaterally between the alae of the sacrum and the ilia. The body of the sacrum (answer a) is in the midline and normal. The sacroiliac ligaments might have been sprained by the trauma of the fall. The pathway for spinal nerves (answer c) is through foramina of the sacrum, not through long bony canals. Similarly, the pathway for the gluteal arteries
(answers d and e) is through the greater sciatic foramen between the ilium and the sacrum.
10.
In the hysterosalpingogram below, the dye at C is within which of the following?
Correct Answer
B. Peritoneal cavity
Explanation
(Moore and Dalley, pp 424, 469.) Peritoneal cavity. The purpose of performing a hysterosalpingogram is to determine if the fallopian tubes are open and thus potentially capable of transporting sperm and eggs for conception. The dye is generally introduced via a catheter placed through the cervix and injected into the uterus. In this case it seems as if dye is spilling into the peritoneal cavity at ends of each fallopian tube. The dye would pass the isthmus of the oviduct next to the body of the uterus. Within the image (E) is the vagina, (D) is the isthmus of the cervix, (B) is the body of the uterus, and A is the ampulla of the oviduct just proximal to the infundibulum out of which dye is flowing as curling wisps.
11.
. Which of the following locations is optimal for fertilization of an ovulated egg by sperm to occur?
Correct Answer
A. Ampulla of the oviduct
Explanation
(Moore and Dalley, p 424.) Ampulla of the oviduct. Fertilization normally occurs in the ampulla of the oviduct within 24 hours of the egg’s release from the ovary. The wall of the uterine cavity (answer b) is the normal site of implantation about 4 days later. Fertilization normally does not occur either in the infundibulum (answer c) nor isthmus of the oviduct (answer d). Sperm must pass through cervical (answer e) mucous to reach the uterus.
12.
Which of the following contains the ovarian neurovascular bundle?
Correct Answer
D. Suspensory ligament of the ovary
Explanation
(Moore and Dalley, pp 428–429.) The mesosalpinx (answer b), mesovarium (answer c), and suspensory ligament are all continuous with the broad ligament (answer a), which is a reflection of peritoneum over the female reproductive organs. The mesovarium attaches the ovary to the broad ligament. The suspensory ligament of the ovary runs from the pelvic brim to the lateral pole of the ovary. It contains the ovarian artery, ovarian vein, ovarian lymphatics, and ovarian nerves (ovarian neurovascular bundle). Volvulus of the ovary (usually associated with an ovarian tumor) may constrict the neurovascular bundle with ovarian infarct and pain referred to the inguinal and hypogastric regions. The base of the broad ligament has the transverse cervical ligament (answer e).
13.
Following the birth of her third child a 38-year-old woman was undergoing a hysterectomy because of pelvic pain associated with endometriosis. Since she had an android pelvis, cesarean sections had been performed with each delivery of her children. An open (surgical) hysterectomy approach was performed in order to also remove any peritoneal endometrium, in which the ovaries were to be spared. The OB specifically identified and spared a right and left ureter during the clamping and removal of the uterine arteries. After surgery, she developed left sided low back pain. An intravenous pyelogram was ordered and showed normal function of the right kidney and normal function of the upper portion of the left kidney, but there was little kidney function in the inferior pole of the lower portion of the left kidney and two ureters exiting from that kidney. What likely happened during the hysterectomy?
Correct Answer
B. Damage to one of the left duplicated ureters
Explanation
. (Moore and Dalley, p 387. Sadler, p 235.) Partial or complete duplication of the ureters is a fairly common (1 in 125 births) occurrence. While the OB carefully identified both a right and left ureter and spared them during the clamping and removal of the uterine arteries the duplicated ureter on the left side most likely was not noticed and thus damaged. The pain is most likely due to a collection of urine or an “urinoma.” Duplicated ureters are at greater risk since they are often smaller than normal ureters. If the site of damage could be identified, then the duplicated left ureters could be connected above the damage to the undamaged ureter and may preserve full kidney function. While a pyelogram
(answer a) does require injection of an iodine based dye that can cause some kidney damage, this should not cause damage specifically to the inferior half of the left kidney. Renal failure following anesthesia (answer c) is relatively rare. The development of the kidney stone (answer d) within one of the left duplicated ureters would be unlikely, but if present then the stone should be evident on the pyelogram images. Thus, “answer d” is a good second choice answer.
14.
Pap smears are the collection of cells from the uterine cervix to look for cytological evidence of transformation to cancerous forms, most typically due to a viral infection. While most women do not report any discomfort associated with the collection of cervical cells, a few women do. To which of the following somatic areas does the uterine cervix refer pain to?
Correct Answer
D. Lateral leg and perineum
15.
Episiotomies are performed to control tearing during a vaginal delivery. When performing a mediolateral episiotomy, an OBGYN will likely cut through several structures of the perineum. What perineal structures must be sutured back together following a typical mediolateral episiotomy?
Correct Answer
C. Vaginal wall, bulbospongiosus, and superficial transverse perineal muscles
Explanation
(Moore and Dalley, pp 436, 438.) Vaginal wall, bulbospongiosus, and superficial transverse perineal muscles. Both the pubococcygeus and iliococcygeus muscle (answers a and b) are part of the pelvic diaphragm and are much deeper muscles and thus would not be cut. The prepuce and rectus abdominis muscle (answer d) are superior and lateral to the vagina and an episiotomy is performed in a posterior mediolateral direction, not anterior mediolateral direction. Both the sacrospinous
and sacrotuberous ligaments (answer e) are much deeper structures, which stabilize the pelvis and never cut during an episiotomy.
16.
A man comes to your office because he thinks he has bilateral hernias and bilateral pain in the inguinal area. Upon physical examination he does not have a direct nor indirect inguinal hernia, but does have bilateral palpable superficial inguinal lymph nodes, which are tender. You formulate a differential diagnosis of locations from which lymph drains into the superficial inguinal lymph nodes. Which anatomical region or structure does not drain into the superficial inguinal lymph nodes and thus should be
EXCLUDED from your differential diagnosis list?
Correct Answer
C. Testicles
Explanation
(Moore and Dalley, pp 392–393, 431, 452.) Lymph drains from the testicles to preaortic nodes, because remember that the blood supply for the testicles comes directly off the abdominal aorta, where the testicles first develop, prior to their inferior migration into the scrotum.
All the other pelvic structures: penis (answer a), scrotum (answer b), anus (answer d), and epididymides (answer e) can drain lymphatics to the superficial inguinal nodes. The anus and rectum have drainage to three sites: superficial inguinal nodes, internal iliac nodes, and inferior mesenteric preaortic nodes.
17.
A 35-year-old married woman comes to the emergency room due to sudden onset of nausea, vomiting, positional hypotension, and tachycardia. She also complains of sudden abdominal fullness and generalized pelvic pain. Her period is “late,” with the last menses 55 days ago. A pregnancy test is positive. Pelvic sonogram suggests extravasated fluid in the peritoneal cavity and pooling in the rectouterine pouch (of Douglas) and a mass in the left fallopian tube. A culdocentesis yields fresh blood. You correctly suggest that she be admitted for which of the following?
Correct Answer
B. Endoscopic exploration to rule out ectopic pregnancy
Explanation
Moore and Dalley, pp 413, 426–427.) Endoscopic exploration to rule out ectopic pregnancy. The positive pregnancy test, the blood in the cul-de-sac of Douglas and the mass in the uterine tube all suggest ectopic pregnancy. All the other possible answers (answers a, c, d, and e) do not fit with a positive pregnancy test and are much lower frequency events.
18.
A 50-year-old multiparous woman comes to your office to rule out
cancer. She reports a growing mass or fullness on the anterior wall of her
vagina. Upon physical examination you detect a soft, bulging, and a very
compressible mass on the anterior surface of the vagina. When you push
on the bulging mass she feels the need to urinate. You order a CT because
you suspect which of the following?
Correct Answer
B. Cystocele
Explanation
(Moore and Dalley, p 400.) Cystocele. Bulges in the anterior wall of the vagina are most likely due to the bladder falling posteriorly into the anterior vaginal wall. A bulge on the posterior wall of the vagina would most likely be a rectocele (answer b). Cervical cancer (answer c) generally would not present as described. A didelphic uterus (answer d) is a duplication of the uterus as result of failure of the right and left paramesonephric ducts to fuse in the midline. An indirect inguinal hernia (answer e) would generally present as a mass within the labia major.
19.
A 30-year-old woman makes her first prenatal visit to your office. She is excited and anxious as this is her first pregnancy. She brings up the topic of pain relief during vaginal delivery. She states that she would like to try “natural birth” but would like to have the option of some pain relief. However, she would prefer not to have a caudal epidural block. You suggest a pudendal nerve block. One of the advantages of a pudendal nerve block is that the woman can still feel uterine contractions and thus can actively participate in the birthing process, yet also has some pain relief. What would you tell your patient regarding how to perform a pudendal nerve block and an advantage to performing the injection transvaginally versus injecting through perineal skin?
Correct Answer
B. The pudendal nerve serves the skin around the posterior/lateral entrance of the vagina; the nerve wraps around the ischial spine, which is used as a landmark; transvaginal administration is less painful since the upper portion of the vagina has fewer pain receptors
Explanation
(Moore and Dalley, pp 422–423, 465–466.) The pudendal nerve serves the skin around the posterior/ lateral entrance of the vagina; the nerve wraps around the ischial spine, which is used as a landmark; transvaginal administration is less painful since the upper portion of the vagina has fewer pain receptors. The pudendal nerve serves the skin around the posterior/lateral entrance of the vagina; the nerve wraps around the ischial spine, which is used as a landmark; transvaginal administration is less painful since the upper portion of the vagina has fewer pain receptors [thus none of the other (answers a, c, and d) are correct].