4.2 Pelvic Floor

Question 1

where does the deep perineal fascia attach to?

Answer 1

Laterally, it is attached to the ischiopubic rami and is fused to the suspensory ligament of the clitoris.

Question 2

what does the deep perineal fascia surround?

Answer 2

The deep perineal fascia surrounds the ischiocavernosus, bulbospongiosus and transverse perineal muscles

Question 3

whaere does the fatty superficial layer of the superficial perineal fascia attach to?

Answer 3

The fatty superficial layer is continuous anteriorly and superiorly with the fatty layer of the subcutaneous tissue of the anterior abdominal wall.

Question 4

whaere does the deep membranous layer of the superficial perineal fascia attach to?

Answer 4

Attachments of the deep membranous layer include the posterior margin of the perineal membrane and the perineal body (posteriorly) and the medial aspect of the superior part of the thigh (laterally).

Question 5

what does the superficial perineal pouch contains?

Answer 5

the clitoris and ischiocavernosus muscles,
the bulbs of the vestibule and bulbospongiosus muscle,
the greater vestibular glands,
deep perineal branches of the internal pudendal vessels and pudendal nerve and
superficial transverse perineal muscles.

Question 6

what are the boundaries of the superficial perineal pouch?

Answer 6

otential space between the deep membranous layer of the subcutaneous tissue and the deep perineal fascia, laterally limited by the ischiopubic rami.

Question 7

what are the boundaries of the deep perineal pouch?

Answer 7

The deep perineal pouch is a potential space between the perineal membrane inferiorly, the inferior fascia of the pelvic diaphragm superiorly and laterally the fascia covering the obturator internus muscle. It contains the

Question 8

what are the contents of the deep perineal pouch?

Answer 8

proximal part of the urethra and external urethral sphincter,
the deep transverse perineal muscles and
the neurovascular bundle of the clitoris.

Question 9

Between the urogenital hiatus and the anal canal lies a fibrous node known as the _____________, which joins the pelvic floor to the perineum and in women acts as a tear resistant body between the vagina and external anal sphincter, supporting the posterior part of the vaginal wall against prolapse.

Answer 9

perineal body

Question 10

What is the function of the puborectalis?

Answer 10

Puborectalis has very important functions in continence. It is a u-shaped sling which extends from the bodies of the pubic bones, past the urogenital hiatus, and around the anal canal.

Its tonic contraction bends the canal anteriorly, creating the anorectal angle (90 degrees) at the anorectal junction (where the rectum meets the anus). Its function is therefore to maintain faecal continence. During defecation, the muscle relaxes and allows the anal canal to straighten.

Of note, some fibres of the puborectalis muscle (pre-rectal fibres) form another U-shaped sling that loop around the urethra and vagina in the female. These fibres are very important in preserving urinary continence, especially during abrupt increase of the intra-abdominal pressure i.e. during sneezing.

Question 11

where does the pubococcygenous attach to?

Answer 11

The pubococcygeus forms the main part of levator ani. It arises from the body of the pubic bone and the anterior aspect of the tendinous arch, also known as the white line. The fibres travel around the margin of the urogenital hiatus and run posteromedially, attaching at the coccyx and anococcygeal ligament.

Question 12

where does the iliococcygeus attach to?

Answer 12

The iliococcygeus has thin muscle fibres, which start anteriorly at the ischial spines and posterior aspect of the tendinous arch. They attach posteriorly to the coccyx and the anococcygeal ligament. This part of the levator ani is the actual “levator” of the three: its action elevates the pelvic floor and the anorectal canal.

Question 13

where does the coccygeous attach to?

Answer 13

The coccygeus is a muscle located posterior to levator ani and anterior to the sacrospinous ligament. It is a triangular plane of muscular and tendinous fibers. It arises at its apex from the spine of the ischium and sacrospinous ligament, and inserts its base into the lateral margins of the coccyx and into the side of the lowest portion of the sacrum.

Question 14

what is the coccygeus muscle innervated by?

Answer 14

innervated by the anterior rami of S4 and S5.

Question 15

what is the blood supply of the pelvic floor?

Answer 15

The blood supply of the pelvic floor is derived from the internal iliac artery branches: the vaginal artery, the inferior gluteal artery, and the pudendal artery.
Note that the homologue to the vaginal artery in males is the inferior vesical artery.

Question 16

What is the nerve supply of pelvic floor?

Answer 16

The sacral plexus is formed by the ventral rami of S 1-4 spinal nerves and the lumbosacral trunk, containing fibres of ventral rami of L4-5 spinal nerves.
It is located on the posterior wall of the true pelvis where it runs in front of the piriformis muscle.

Question 17

what is the route of the pudendal nerve?

Answer 17

The pudendal nerve passes between the piriformis and coccygeus muscles and leaves the pelvis through the greater sciatic foramen. It crosses over the sacrospinous ligament and reenters the pelvis through the lesser sciatic foramen. After reentering the pelvis, it accompanies the internal pudendal vessels along the lateral wall of the ischioanal fossa within the pudendal canal, a sheath of the obturator fascia. This canal is also known as Alcock’s canal after the anatomist who discovered it.

Question 18

what are the branches of the pudendal nerve?

Answer 18

The first branches of the pudendal nerve are the inferior rectal nerves supplies the skin around the anus, external anal sphincter, and anal canal below the pectinate line.

The pudendal nerve continues forward in the pudendal canal to divide into the perineal nerve and the dorsal nerve to the clitoris. The perineal nerve leaves the pudendal canal and separates into superficial and deep divisions.

Question 19

what are the functions of the pudendal nerve?

Answer 19

Motor Functions: Innervates the skeletal muscles in the perineum, the external urethral sphincter, the external anal sphincter, levator ani.
Sensory Functions: Innervates the penis and the clitoris and most of the skin of the perineum.