Block 7 Anat Pelvis BRS Pretest W Xpl Prt 1

(Moore and Dalley, pp 384–386.) All of the listed choices are branches of the internal iliac artery. The inferior vesical artery in the male supplies the seminal vesicle, prostate, fundus of the bladder, distal ureter, and the vas deferens. In the female, the vaginal artery supplies the vagina, urinary bladder, and pelvic portion of the urethra. The obturator artery (answer a) gives off muscular and nutrient branches within the pelvis and then leaves the pelvis via the obturator canal to supply the thigh. The internal pudendal artery (answer b) crosses the piriformis muscle, exits the pelvic cavity via the greater sciatic foramen, and enters the ischiorectal fossa via the lesser sciatic foramen. It supplies the external genitalia (penis and clitoris). The middle rectal artery (answer c) supplies the inferior rectum and forms important anastomoses with other rectal arteries. The umbilical artery (answer d) gives off the superior vesical artery in both sexes. Its distal portion degenerates to form the medial umbilical ligament.

(Kierszenbaum, pp 557–558.) The thick secretion from the seminal vesicles contributes substantially to the ejaculate volume that conveys the spermatozoa. The high fructose content of secretions of the seminal vesicles provides the primary metabolic energy source for sperm motility. The flavins that are contributed to the ejaculate by the seminal vesicles fluoresce strongly in ultraviolet light, a phenomenon that supplies a useful forensic test for the presence of semen. Bulbourethral glands (answer a) produce mucus that lubricates the urethra upon erotic stimulus. The epididymis (answer b) stores sperm. The prostate gland (answer c) produces proteins responsible for semen liquefaction. The testis (answer e) produces sperm.

(Moore and Dalley, pp 220–221, 225.) The efferent portion of the cremasteric reflex is mediated by the genital branch of the genitofemoral nerve, which innervates the cremasteric muscle (skeletal). The femoral branch (answer a) supplies the afferent limb, and the genital branch supplies the efferent limb. The ilioinguinal nerve (answer c) provides sensory innervation to the medial aspects of the thigh and the anterior aspects of the mons or the base of the penis and can also provide afferent innervation to stimulate the cremasteric response, pulling the testicles upward. The pudendal nerve (answer d) provides sensation to most of the skin of the perineum as well as the motor supply to the perineal muscles. The involuntary scrotal reflex can also be based on temperature (answer e): warmth causes relaxation of the cremasteric (skeletal) and dartos (smooth) muscle, whereas cold causes contraction of both the cremasteric and dartos muscles.

(Moore and Dalley, pp 396–371, 436–438.) The muscle indicated is attached to the pubic bone and extends around the rectum. It is the puborectalis portion of the levator ani (pelvic diaphragm). The puborectalis is responsible for fecal continence. The urogenital diaphragm (answer a) is positioned inferior to the pelvic diaphragm and includes the deep transverse perineal muscle. The obturator internus (answer c) covers the lateral wall of the lesser pelvis. The obturator externus
(answer d) is found in the deep thigh.

(Casals, pp 1476–1483.) If the brother has a child with cystic fibrosis, then he must be a carrier of the cystic fibrosis gene, meaning there is a 50% chance that the husband is a CF carrier. Congenital absence of the ejaculatory ducts is increased in carriers of CF. If the ejaculatory ducts are absent, then there should be no sperm from the vas deferens (normally 0.5 mL of the semen volume) and no products of the seminal vesicles (normally 2.0 mL of the semen volume). The seminal vesicle is responsible for fructose normally present in the ejaculate. Prostatic secretions are normally slightly acidic. The normal physical of the husband rules out hypospadias (answer b), bilateral cryptorchidism (answer a), and hydrocele (answer d). The congenital absence of the prostate gland is extremely rare (answer e).

(Moore and Dalley, pp 358–359, 361.) The pelvis is most likely that of a 14-year-old male. Because the subpubic angle is about 60and the pelvic brim is heart shaped, you are looking at a male not a female (answers b and d). The bones of the pelvis arise from three different centers of ossification and generally fuse together between puberty and the twenty-third year. Therefore, you know you are looking at a 14-year-old male, not a 3-year-old (answer a; would have 3 separate pelvic bones) nor an 80-year-old (answer e; pelvic bones would be fused).

(Moore and Dalley, pp 319–320, 393.) A, c, and d. Renal and ureteric calculi (laymen’s kidney stones) generally are formed in the kidneys and then lodge at one of three locations: 1) at the junction of the renal pelvis with the ureter; 2) as the ureters cross the external iliac vessels at the pelvic brim; and 3) as the ureters pass through the wall of the bladder (see Fig. 3.14 A, p 393 Moore & Dalley). Stones generally do not lodge at the edge of the greater pelvis [answer b; all other answers (a, c, d, and e) are incomplete]. The referred pain from ureteric calculi is usually described as from “loin to groin” in that it often starts in back and side over the kidney and then extends in a band down towards the labia majora or scrotum (from T 11 to L2). Normally the pain is intermittent and comes and goes in waves and may change in location, generally moving inferiorly with time. Since the ureters undergo peristaltic movement, the calculi often move with time. Depending on the chemical composition and shape of the calculi they may either block urine flow or if spiky, stick into the wall of the ureter. Kidney stone pain is often described as being worse than labor pains. Treatments include pain relief and drinking lots of fluids, and either lithotripsy (use of ultrasound waves to break up the stone) or physical removal (surgical) of the stone in severe cases.

(Moore and Dalley, pp 225–226.) The newborn boy has congenital hydrocele. As the testicles migrate from the posterior abdominal wall to the anterior abdominal wall through the inguinal canal, they bring a process of the peritoneal lining, the processes vaginalis, which is filled with fluid and is connected to the peritoneal cavity. Normally, this process vaginalis disconnects from the abdominal cavity and forms the tunica vaginalis. Sometimes due to the late migration of the testis, the process vaginalis does not lose its connection with the peritoneal cavity, so that during straining and coughing or crying the scrotum swells. Normally this condition spontaneously corrects itself a few months after birth. Cryptorchidism (answer a) is the failure of the testis to migrate down into the scrotum, but the physical exam indicated the testes were in the scrotum. A direct inguinal hernia (answer b) is very rare in newborns. Congenital varicocele (answer c) would generally appear bluish and would feel like a bag of worms. Klinefelter’s newborn (answer e) would have normal-sized testicles and is not related to a hydrocele.

(Moore and Dalley, p 361.) The subpubic angle between inferior pubic rami is significantly greater (about 85) in the female than in the male (about 60) and this is perhaps the best identifying feature of the female pelvis. The female pelvis is generally lighter than the male pelvis. The male pelvis generally has more definitive muscle markings, which reflect the larger male musculature and generally heavier male build. In the female the false or greater pelvis tends to be shallower (answer b) with flared ilia. The female pelvic inlet tends to be more oval (answer a), rather than the heart-shaped inlet of most male pelves. The female pelvic outlet is generally larger (more suitable for child bearing)
than the male pelvis (answer c).

(Moore and Dalley, p 409. Kierszenbaum, p 559.) Benign prostatic hypertrophy is the result of enlargement of the mucosal and submucosal (median) region, which may compress the prostatic urethra leading to urinary retention [thus not (answer a)]. This hypertrophic tissue may also protrude into the urinary bladder to prevent complete emptying. The lateral/posterior lobes (answer b) are commonly associated with malignant transformation. The anterior region (answer d) tends to be
asymptomatic due to its mainly fibrous nature.

(Moore and Dalley, pp 228–229.) It is very uncommon. Varicocele usually occurs on the left side (~95%) and is rare on the right (answer b). Left varicocele results from local venous congestion caused by compression of the testicular vein as it passes beneath the usually full sigmoid colon. Testicular torsion (answer c), wherein a long mesorchium (answer d) is a contributing factor, strangulates the testicular artery, and produces testicular ischemia, not varicocele. Testicular torsion is a medical emergency which normally presents in adolescents as sudden testicular pain (Moore and Dalley, p 226).

(Moore and Dalley, pp 441–442.) The blood from straddle injuries is generally limited to the superficial perineal space which is bound by the superficial membranous fascia (superficially; including Scarpa’s fascia on the anterior abdominal wall, dartos fascia on penis and scrotum, and Colles’ fascia on the urogenital triangle) and the deep perineal membrane (deep). The superficial membranous fascia is attached to deep structures at the following locations: superiorly the superficial membranous fascia attaches to the deep fascia of the anterior abdominal muscles about half way between the pubic symphysis and the umbilicus; attaches to the inguinal ligament, and the fascia lata, laterally; and attaches to the posterior edge of the perineal membrane just anterior to the anus Camper’s fascia (answer a) is the fatty layer on the anterior abdominal wall, which extends beyond the umbilicus. Transversalis fascia (answer b) is the fascia just deep to the peritoneal lining in the abdomen. Dartos fascia (answer c) only covers the scrotum and penis. The inferior fascia of the pelvic diaphragm (answer e) is deep to the perineal membrane.

. (Moore and Dalley, pp 373, 375, 467.) The pubococcygeus muscle is the most frequently torn muscle that results in femaleincontinence. The puborectalis, pubococcygeus, and iliococcygeus comprise the levator ani, the main muscular component of the pelvic floor. The
pubococcygeus is the part of the levator ani most frequently damaged during parturition. Because the pubococcygeus surrounds and supports the neck of the bladder and the proximal urethra, urinary leakage is a common result, particularly during increased abdominopelvic pressure, as occurs, during coughing. Damage to the puborectalis (answer a) results in fecal incontinence under similar situations. Both the obturator internus muscle (answer b) and the piriformis (answer e) are parts of the lateral wall of
the pelvis and assist in lateral rotation of the thigh. Generally damage to the superficial transverse perineal muscle (answer d) would be of little significance.

(Moore and Dalley, pp 404, 409, 433.) In most males, during a digital rectal exam, you can palpate the main peripheral portion of the prostate gland (answer a), then just a little more cranially, both the seminal vesicles (answer c) and ampulla of the vas (ductus) deferens (answer e). The main goal of the digital rectal exam is to palpate the backside of the prostate gland which is the main peripheral portion of the gland; the site of development of most growth of prostate cancer. An additional screening tool is the prostate specific antigen (PSA) level within blood. Generally the PSA level should be below 2.5 ng/mL. Elevated levels of PSA, however, can also indicate inflammation of the prostate in addition to cancerous growth. You can not palpate the ejaculatory ducts (answer b) as they are embedded within the substance of the prostate gland. You can not palpate the epididymis (answer d) during a digital rectal exam as it is within the scrotum next to the testicles. All other answers (f, g, and i) are wrong or incomplete.

(Moore and Dalley, p 431.) Lymph from the anal region is drained to three different regions because its blood supply comes from three different regions [thus (answers a and b) are incomplete]. Superior to the pectinate line the lymph drains into the internal iliac nodes and preaortic nodes (along the path of the superior rectal artery, a branch off the inferior mesenteric artery). Inferior to the pectinate line the lymph drains into the superficial inguinal nodes. Thus the external iliac nodes have nothing to do with the rectum [thus not (answers d and e)].

(Moore and Dalley, pp 387, 414.) The ureter, lying just medial to the internal iliac artery in the deep pelvis, passes from posterior to anterior immediately inferior to the lateral cervical ligament. This ligament sits at the base of the broad ligament and contains the uterine artery and vein to which the ureters pass inferior approximately midway along their course between internal iliac artery and uterus. The ureter continues inferior to the anterior portion of the lateral cervical ligament (where it can sometimes be palpated through the walls of the vagina at the lateral fornices) to gain access to the base of the urinary bladder. The close association between uterine vessels and ureter is of major importance during surgical procedures in the female pelvis. At the top of the broad ligament would be the ovarian artery and vein (answers a and e), which continue on to supply blood to the fundus. The uterine tube (answer b) also runs along the top of the broad ligament. The round ligament of the uterus (answer c) runs anterior to the broad ligament.

(Moore and Dalley, pp 218–219.) In the female, the gubernaculum becomes the round ligament of the uterus and the proper ligament of the ovary. The gubernaculum, which runs from the gonadal anlage to the sexually undifferentiated labioscrotal fold, guides the descent of the testes into the scrotum in the male and the descent of the ovary into the true pelvis in the female. In the female, the developing uterus grows into the gubernacular tract and divides it into the proper ligament of the ovary and the round ligament of the uterus. Thus, the proper ligament of the ovary runs within the broad ligament from the medial pole of each ovary to the uterus. It then continues within the broad ligament as the round ligament of the uterus into the deep inguinal ring. It thereby gains access to the canal of Nuck (the female homologue of the inguinal canal; (answer a) to insert into the major labial folds. The suspensory ligament of the ovary (answer e) contains the ovarian arteries and veins. Answers c
and d are thus incomplete.

(Moore and Dalley, pp 423, 425.) The visceral afferent fibers that mediate sensation from the fundus and body of the uterus, as well as from the oviducts, tend to travel along the sympathetic nerve pathways (via the hypogastric nerve and lumbar splanchnics) to reach the upper lumbar levels (L1–L2) of the spinal cord. Thus, uterine pain will be referred to (appear as if originating from) the upper lumbar dermatomes and produce backache. The visceral afferent fibers that mediate sensation from the cervical neck of the uterus travel along the parasympathetic pathways [via the pelvic splanchnic nerves (nervi erigentes); (answer c)] to the midsacral levels (S2–S4) of the spinal cord. In this instance, pain originating from the cervix will be referred to the midsacral dermatomes and produce pain that appears to arise from the perineum, gluteal region, and legs. Neither the lumbosacral trunk to L4–L5 (answer b) nor the pudendal nerve (answer d) should be involved.