clinical correlations pelvis

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The pudendal nerve arising from the sacral plexus (S2, S3, and S4) is the major nerve of the perineum. It is both motor and sensory to the region and also carries some post-ganglionic sympathetic fibers to the perineum. In the female it branches include: the perineal nerve, which provides branches to the posterior labial region and the surrounding musculature; the dorsal nerve of the clitoris, which supplies the prepuce and glans of the clitoris and the associated skin; and the inferior rectal nerves, which supply the perianal region. The pudendal canal (Alcock's canal) is the canal is formed in the obturator fascia (archus tendinous obdurator) along the lateral wall of the ischiorectal fossa. Passing anteriorly within the pudendal canal are the pudendal nerve, internal pudendal artery and vein on their way to the perineum. The location to deliver anesthetic to the pudendal nerve is within the pudendal canal as the nerve wraps itself around the ischial spine and before it sends out its branches. The palpating finger is used to locate the ischial spine and sacrospinous ligament per vaginam. The needle is inserted through the vaginal wall, is directed towards the spine and then passed through the sacrospinous ligament. As soon as the needle has passed through the ligament, a loss of resistance is felt. At this point 10mls of local anaesthetic solution (eg 1% Lignocaine with adrenaline) is injected after careful aspiration.

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Page 1: Clinical Correlations pelvis

The pudendal nerve arising from the sacral plexus (S2, S3, and S4) is the major nerve of the perineum. It is both motor and sensory to the region and also carries some post-ganglionic sympathetic fibers to the perineum. In the female it branches include: the perineal nerve, which provides branches to the posterior labial region and the surrounding musculature; the dorsal nerve of the clitoris, which supplies the prepuce and glans of the clitoris and the associated skin; and the inferior rectal nerves, which supply the perianal region.

The pudendal canal (Alcock's canal) is the canal is formed in the obturator fascia (archus tendinous obdurator) along the lateral wall of the ischiorectal fossa. Passing anteriorly within the pudendal canal are the pudendal nerve, internal pudendal artery and vein on their way to the perineum.

The location to deliver anesthetic to the pudendal nerve is within the pudendal canal as the nerve wraps itself around the ischial spine and before it sends out its branches. The palpating finger is used to locate the ischial spine and sacrospinous ligament per vaginam. The needle is inserted through the vaginal wall, is directed towards the spine and then passed through the sacrospinous ligament. As soon as the needle has passed through the ligament, a loss of resistance is felt. At this point 10mls of local anaesthetic solution (eg 1% Lignocaine with adrenaline) is injected after careful aspiration.

Other way is to administer anesthetic in the perineal procedure, the ischial tuberosity is palpated through the buttock and the needle is inserted into the pudendal canal about one inch deep medial to the ischial tuberosity. The anesthetic can then be injected to bathe the pudendal nerve.

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Complete anesthesia of the perineal region requires anesthetization of the genital branches of the ilioinguinal nerve, the genitofemoral nerve, and the perineal branch of the posterior femoral cutaneous nerve.

The rectouterine pouch (of Douglas) is the formed as the peritoneum of the abdomen extends down over the posterior portion of the uterus and cervix and is reflected back upward covering the upper half of the rectum. This "dip" of peritoneum creates a space or pouch above the posterior fornix of the vagina.

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The uterine artery is the most significant source of blood to the uterus and therefore requires careful dissection. It is generally a branch of the internal iliac artery which supplies the uterus and uterine tube.

The other major blood supply to the region is the ovarian artery which a direct branch off the aorta and travels in the suspensory ligament of the ovary. The vaginal artery would not need to be ligated.

The ureters pass under the uterine arteries on their way to the bladder - "yellow water" under "red bridge" is the term frequently used to describe their passage.

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Ligaments THAT NEED TO BE CUT TO DO A HYSTERECTOMY:

Transverse Cervical Ligament (Cardinal Ligament) This extends from the cervix and lateral parts of the vaginal fornix to the lateral walls of the pelvis.

The Uterosacral Ligament (Sacrocervical Ligament) These pass superiorly and slightly posteriorly from the sides of the cervix to the middle of the sacrum. The uterosacral ligaments tend to hold the cervix in its normal

relationship to the sacrum.

The Round Ligament of the Uterus These ligaments are 10 to 12 cm long and extend for the lateral

aspect of the uterus, passing anteriorly between the layers of the broad ligament.

They leave the abdominal cavity through the inguinal canal and insert into the labia majora.

The Ligament of the Ovary (proper ovarian ligament) These ligaments are thickenings of the broad ligament as it

drapes the gap between ovary and the uterus. The ovarian ligament attaches ovaries to the uterus.

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Uterine prolapse, often combined with cystocele is one of the most frequently encountered gynecological disorder. Advancing age brings an increased relaxation and loss of tonus of the pelvic diaphragm and the ligaments that constitute the support of the pelvic viscera. This fact is mainly responsible for the disorder. Following multiple chidbirths, tearing and overstretching of the supporting tissues greatly enhance the chances for prolapse.

Account for the urinary symptoms observed in this patient, and what is stress incontinence and why might coughing, sneezing, or lifting cause it?Because of the dislodgment of the bladder and change in urethrovesicular, residual urine remains in the bladder after urination, resulting in periodic infection of the stagnating urine and cystitis. Frequency and burning are typical signs that result from urinary retention.

Stress incontinence is the involuntary dribbling of urine caused by an increase in the intra-abdominal pressure when the abdominal muscles contract, as in coughing, sneezing, lifting and the like. Weakening of the pelvic diaphragm and related fascias may compromise the urethral sphincters impeding their ability to resist this stress, resulting in leakage.

Urinary flow is controlled voluntarily by the sphincter urethrae muscle located around the membranous portion of the urethra. In the female, this action is assisted by the pubovaginalis portion (levator prostate in the male) of the levator ani.

How is the uterus ordinarily supported and what causes prolapse? The uterus is supported by the pelvic floor and the viscera surrounding it (i.e. the bladder, rectum, etc.). The pelvic floor or diaphragm is comprised of the levator ani and coccygeus muscles. As the pelvic floor weakens due to aging or injury (like from multiple childbirths), the pelvic organs, including the uterus, will begin to sag if the pelvic diaphragm tone cannot be maintained. The majority of women experience prolapse to some degree, especially after menopause. Several fascial ligaments, including the round ligament of the uterus and the rectouterine ligaments, and to some extent the "cardinal" ligaments help maintain the orientation of the uterus and cervix, but they are not capable of supporting them alone.

The cystocele caused a bulge in the anterior wall of the vagina. What structures could prolapse and cause a bulge in the posterior wall of the vagina? Loops of the small intestine in the rectouterine pouch may cause a bulge at the posterior fornix (enterocele) and the rectum may bulge into the lower vagina (rectocele).

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 The superficial perineal pouch is a potential space between the membranous layer of the superficial perineal fascia (Colles fascia) and the perineal membrane (inferior urogenital fascia).

The deep perineal pouch is not actually an enclosed space. It is the formed between the layers of the urogenital fascias, the superior urogenital fascia above, and the inferior urogenital (perineal membrane) fascia below.

Colles fascia (deep scarpa)

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In males the superficial perineal pouch contains the:

bulb of the penis and the bulbospongiosus muscle crura of the penis and the ischiocavernosus muscle

superficial transverse perineal muscle

proximal part of the spongiosum urethra

branches of the pudendal nerve and internal pudendal artery

In females the superficial perineal pouch contains the:

crura of the clitoris along and the ischiocavernosus muscle bulbs of the vestibule and the surrounding bulbospongiosus muscle

superficial transverse perineal muscle

branches of the pudendal nerve and internal pudendal artery

greater vestibular glands

In males the deep perineal pouch contains the:

membranous urethra extenal urethral sphincter muscle

deep transverse perineal muscle

branches of the pudendal nerve and internal pudendal artery

bulbourethral glands (Cowper’s glands)

In females the deep perineal pouch contains the:

proximal part of the urethra extenal urethral sphincter muscle

deep transverse perineal muscle

branches of the pudendal nerve and internal pudendal artery

Superficial fascial layer of UG diaphragm + deep transverse perineal muscle + inferior fascial layer of UG diaphraghm = UG diaphraghm

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The male urethra begins at the neck of the bladder and passes inferiorly to traverse the prostate gland, during which it is called the prostatic urethra.

Beyond this it traverses the urogential diaphragm, where it is known as the membraneous urethra.

Finally it enters the bulb of the corpus spongiosum (bulbourethra) and then travels distally toward the end of the penis. Through out this distal course it is know as the penile or spongiose urethra after it has exited the body.

The prostatic urethra receives secretions from the prostate and also receives fluids from the seminal vesicles and sperm from the ductus deferens. The membraneous urethra receives the secretions of the bulbourethral glands.

Straddle Injury Case:An 8-year-old boy, while riding his bike hit an obstacle. His hips slid forward off the bicycle seat and he sustained a forceful "straddle" injury as his legs went to either side of the strut extending between the seat and the handlebars. The injury was very painful and he was taken to the emergency room. The ER physician noted that his scrotum was tense and swollen, and the scrotal skin seemed dark in color. The discoloration extended upward and laterally over the lower part of the anterior abdominal wall. It seemed to abruptly end as a rather sharp horizontal line between the anterior iliac spine and the pubic tubercle and not pass down the child's thigh. As the child attempted to urinate there was considerable discomfort and the resultant few drops were blood-tinged. The attending physician informed the boy's parents that he suspected an injury to the child's urethra, with spillage of urine and blood accounting for the discolored regions beneath the skin.

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The urethra has been injured {A} in its penile portion, that is distal to the urogenital diaphragm. In this area the urethra lies within the cylindrical erectile mass called the corpus spongiosum.

Explain the reason why that the subcutaneous fluid did not extend beyond the abdomen and not travel down the thigh?

The discoloration of the skin did not pass down the thigh, but rather ended as sharp horizontal line between the anterior iliac spine and the pubic tubercle. Anatomically Scarpa's fascia (which gives rise to Colles' fascia in the perineum) extends down the abdominal wall to the area of the inguinal ligament, where it curls upon itself to form a tubular sheath

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which is continuous with the perineum. It therefore does not extend over the thigh, and is not continuous with the fascia lata of the thigh but rather forms a line of fusion.

What accounts for the discoloration beneath the skin of the scrotum and anterior abdominal wall?

Tear or rupture of the penile urethra allows urine, mixed with blood from the tear (accounting for the the dark discoloration), to leak into the superficial perineal pouch. It is this tissue space, with its defined borders and attachments, which explains the distinct pattern of the discolored area beneath the skin. Anteriorly, the superficial pouch extends freely up into the superficial fascia of the lower abdomen (Scarpa's Fascia) and continues as a tubular sheath into the scrotum and around the penis. Posteriorly, the superficial pouch ends where Colles' fascia (membranous layer of superficial fascia) attaches to the posterior border of the urogential diaphragm. These distinct boundaries accounts which accounts for the discoloration of the scrotum and up the lower anterior abdominal wall.