9-A The Perineum

Question 1

Which ligament separates the greater and lesser sciatic foramen?

Answer 1

sacrospinous (deep) and sacrotuberous ligaments

Question 2

Describe the borders of the pelvic inlet.

Answer 2

pubic symphysis, iliopectineal lines and sacral promontory (the pelvic outlet is bounded by the pubic arch, ischial tuberosities and the coccyx

Question 3

Name the muscles that make up the pelvic diaphragm.

Answer 3

levitator any , coccyges (keggel exercises) with the arcus tendinous acting as a attachment point

Question 4

What functions as the floor of the pelvis and the roof of the perineum?

Answer 4

the pelvic diaphragm (resist pelvic organ prolapse and help with fecal continence)

Question 5

Describe the hole in the pelvic diaphragm that the urethra and possibly the vagina pass through.

Answer 5

Urogential hiatus

Question 6

What are common birthing techniques that have come to replace the episiotomy?

Answer 6

warm compress during labor, perineal massage

Question 7

The perineum is slip into two triangles, name them

Answer 7

urogenital triangle (anterior) anal triangle (posterior)

Question 8

The orientation of the sacrum and which two inlets make delivery more complicated in humans?

Answer 8

pelvic inlet and outlet

Question 9

Describe the angle between the two perineal triangles viewed from laterally.

Answer 9

approx 120 deg (not a flat structure)

Question 10

What is the role of the ischioanal fosae?

Answer 10

it includes most of the anal triangle and is fat filled, supporting the pelvic organs and allowing for expansion during the passage of feces (loss during starvation can lead to rectal prolapse

Question 11

The perineal membrane serves what purpose?

Answer 11

Anchor of erectile tissue which is located superficial to the perineal membrane (**does not attach anteriorly allowing of passage of nerves and vessels to the penis/clitoris)

Question 12

Which tissue encloses the corpora cavernosa and restricts its expansion, along with restricting drainage of blood through deep dorsal veins?

Answer 12

tunica albugenia

Question 13

What parts of the penis does the corpus spongiosum form?

Answer 13

the bulb of the penis and the glands, where the urethra travels through

Question 14

What is the female analogous to the buburethral gland?

Answer 14

the greater vestibular glands which lie poster tot eh vestibular bulbs

Question 15

Describe the perineal structure that are covered by the ischiocavernosus and the bulbopongiosus.

Answer 15

the crura of the cavernosum and the bulb/spongiosum

Question 16

What muscles anchor the perineal body?

Answer 16

superficial transverse perineal

Question 17

What are the purpose of superficial perineal muscles?

Answer 17

restriction of blood during erection and propulsion of sperm during ejaculation

Question 18

Describe the anatomical position of the penis.

Answer 18

while erect, the anterior portion is ventral and the posterior portion is dorsal

Question 19

Describe the blood and nerve supply that follow the “simple route” v. the “not so simple route”?

Answer 19

simple route (parasympathetics: S2,3,4 and nervi erigentes, and venous drainage of erectile tissue) not so simple exit through the greater sciatic foramen, enter via the lesser sciatic foramen and travel anteriorly throughout the pudendal canal (sensory, somatomotor, sympathetics: spinal nerves S2,3,4, arterial supply and venous drainage of superficial structures)

Question 20

Which fibers stimulate smooth and skeletal muscle contraction during ejaculation and orgasm?

Answer 20

sympathetic and somatomotor fibers

Question 21

Name 3 pairs of arteries and nerves that sere the perineum.

Answer 21

dorsal a and N of the penis/clitoris, the perineal branches a and n. and inferior rectal a. and n.

Question 22

Dorsal artery and nerve run how in relationship tot eh perineal membrane?

Answer 22

deep

Question 23

Name the layers of the pelvis and perineum from deep to superficial.

Answer 23

peritoneum, pelvic organs, pelvic diaphragm, urogenital diaphragm, erictile tissue, superficial perineal muscles and skin

Question 24

Distinguish between male and female erectile tissue.

Answer 24

men have a midline erectile tissue from the bulb to the corpus spongiosum whereas women have a bulb split by the vagina and not contributing to clitoris

Question 25

Define the contents of the deep perineal space.

Answer 25

potential space between the superior and inferior fascia of the UG diaphragm contains the deep transverse perineum and sphincter urethrae muscles (and bulbourethral gland)

Question 26

Define the contents of the superficial perineal space.

Answer 26

the area between the inferior fascia of the UG diaphragm and the superficial perineal fascia is called the superficial perineal space containing the muscles and erectile tissue of the external genitalia, bublospongious and ischiocavernosus muscles

Question 27

Which structures run in the pudendal canal?

Answer 27

the pudendal and pudendal nerve giving rise to the inferior rectal, perineal and dorsal nerve of the penis/clitoris

Question 28

Describe the main drainage routes for the deep dorsal veins of the clitoris and penis.

Answer 28

drain through the deep dorsal vein to the vesical or prostatic plexus to the internal iliac veins