Pelvis and Perineum 1

Question 1

What type of joint is the sacroiliac joint?

Answer 1

plane synovial joint between the sacrum and ilium

Question 2

What sort of movement does the sacroiliac joint allow?

Answer 2

Little movement

Question 3

What does the sacroiliac joint allow?

Answer 3

transmits the weight of the body to the hip bone when a person is standing

Question 4

How is the sacroiliac joint reinforced?

Answer 4

by anterior, posterior, and interosseous sacroiliac ligaments

Question 5

What type of joint is the sacrococcygeal joint?

Answer 5

a cartilaginous joint between the sacrum and coccyx

Question 6

What sort of movement does the sacrococcygeal joint allow?

Answer 6

allows some movement and contains an intervertebral disc between S5 and Co1

Question 7

What type of joint is the pubic symphysis?

Answer 7

a cartilaginous (fibrocartilaginous) joint between the 2 pubic bones

Question 8

What does the sacrospinous ligament do?

Answer 8

divides the greater sciatic foramen from the lesser sciatic foramen

Question 9

How is the female pelvis different to the male pelvis?

Answer 9

-wider pubic arch
-larger pelvic outlet
-a wider and larger pelvic cavity
(all adaptations for childbirth)

Question 10

Where does the levator ani muscle (M) arise from?

Answer 10

1. body of the pubis
2. the arcus tendineus (actually a thickened portion of the obturator fascia) of the levator ani
3. the ischial spine

Question 11

What does the levator ani muscle (M) attach to?

Answer 11

1. the coccyx
2. anococcygeal raphe
3. external anal sphincter
4. walls of the prostate
5. rectum
6. anal canal
7. central tendon of the perineum

Question 12

What is the action of the levator ani muscle (M)?

Answer 12

supports and slightly raises the pelvic floor

Question 13

What is the innervation of the levator ani muscle (M)?

Answer 13

anterior rami of S3 and S4 and perineal branch of the pudendal nerve

Question 14

What are the 3 parts of the levator ani muscle (M)?

Answer 14

1. the the puborectalis
2. the pubococcygeus
3. the iliococcygeus muscles

Question 15

What does the levator ani with the coccygeus muscle form?

Answer 15

• pelvic diaphragm

- supports and raise the pelvic floor

Question 16

Where is the greater sciatic foramen?

Answer 16

superior to the pelvic diaphragm

Question 17

What is the function of the sciatic foramen?

Answer 17

provides a passageway for structures to leave the pelvic cavity and enter the gluteal region

Question 18

Where is the lesser sciatic foramen?

Answer 18

exists inferior to the pelvic diaphragm

Question 19

What is the function of the lesser sciatic foramen?

Answer 19

provides a passageway for neurovascular structures to pass from the gluteal region to the perineum (importantly, the pudendal neurovascular bundle)

Question 20

What does the levator ani allow?

Answer 20

as part of the pelvic diaphragm, provides an important support structure for the pelvic viscera, and especially the female reproductive viscera

Question 21

What else do the levator ani support?

Answer 21

maintain the integrity of the uterus and vagina, as well as support the rectum and assist in defecation by straightening the anorectal junction in both sexes

Question 22

What is the origin of the coccygeus (ischiococcygeus) muscle?

Answer 22

arises from the spine of the ischium and the sacrospinous ligament

Question 23

What is the insertion of the coccygeus (ischiococcygeus) muscle?

Answer 23

attaches to the coccyx and lower portion of the sacrum

Question 24

What is the action of the coccygeus (ischiococcygeus) muscle?

Answer 24

1. With the levator ani, the coccygeus (ischiococcygeus) supports the pelvic floor
2. also draws the coccyx forward after the coccyx has been pushed back during parturition (in females) or defecation

Question 25

What is the innervation of the coccygeus (ischiococcygeus) muscle?

Answer 25

Anterior rami of S4 and S5

Question 26

What area of the levic diaphragm does the coccygeus form?

Answer 26

posterior portion

Question 27

What type of muscles are the muscles of the perineum?

Answer 27

skeletal muscles

Question 28

What are the muscles of the perineum innervated by?

Answer 28

the pudendal nerve and its branches (anterior rami of S2-S4)

Question 29

What is the perineal body?

Answer 29

central tendon of the perineum (perineal body) is a mass of fibromuscular tissue found in the midline between the anus and vagina

Question 30

Why is the perineal body important?

Answer 30

- an attachment point for many of the muscles of the perineum - important for maintaining the integrity of this region

Question 31

What is an episiotomy?

Answer 31

a surgical incision usually made posteriorly (median incision) or posterolaterally in the inferoposterior wall of the vagina to enlarge the vaginal opening during childbirth

Question 32

Why do you carry out an episiotomy?

Answer 32

1. procedure is done only if the normal delivery might result in a tear of the perineum and perineal body would disrupt the integrity of the perineum 2. easier to suture an episiotomy after delivery than to try to repair a nasty tear of the perineal body

Question 33

What is the anatomy of the compressor urethrae muscle and sphincter urethrovaginalis muscle?

Answer 33

1. urethral sphincter might be more of a “urogenital sphincter,” consisting of a compressor urethrae muscle and a sphincter urethrovaginalis muscle 2. The sphincter action of these muscles is debatable

Question 34

How is the compressor urethrae muscle and sphincter urethrovaginalis innervated?

Answer 34

primarily by the perineal branch of the pudendal nerve (S2-S4)

Question 35

What is posterior to the bulb of the vestibule

Answer 35

the greater vestibular (Bartholin’s) gland, which secretes mucus during sexual arousal that lubricates the vaginal opening

Question 36

What happens to the urogenital sphincter complex during childbirth?

Answer 36

- stretched | - weakening its actions both as a sphincter and as a complex of supporting structures of the lower perineum

Question 37

Why are UTIs common in women?

Answer 37

1. shorter urethra | 2. the proximity to pathogens that may be present in the vestibule (the region defined by the labia minora)

Question 38

What is the origin of the sphincter urethrae muscle?

Answer 38

rises from the inferior pubic ramus

Question 39

What does the sphincter urethrae muscle attach to?

Answer 39

to a median raphe and the perineal body

Question 40

What is the action of the sphincter urethrae muscle?

Answer 40

The muscles on both sides act together to constrict the urethra

Question 41

What is the innervation of the sphincter urethrae muscle?

Answer 41

Perineal branch of the pudendal nerve (S2-S4)

Question 42

In women what happens to the sphincter urthrae muscle?

Answer 42

blends with the compressor urethrae muscle and the urethrovaginal sphincter muscles

Question 43

Which sphincter is only found in men?

Answer 43

- women do not possess an internal urethral sphincter - (smooth muscle sphincter at the neck of the urinary bladder) - which is a sphincter muscle found only in men

Question 44

What can stretching during childbirth weaken?

Answer 44

1. integrity of the urogenital sphincter (sphincter urethrae and compressor urethrae muscles) 2. the support structures of the reproductive viscera (pelvic diaphragm, pubovesical and cervical ligament)

Question 45

What is stress incontinence?

Answer 45

involuntary loss of urine after an increase in intraabdominal pressure