Lecture 16: Pelvic Walls, Muscles & Fascia

Question 1

Where does piriformis exit the pelvis?

Answer 1

Greater sciatic foramen on posterior wall

Question 2

Where is obturator interns located?

Answer 2

Lateral pelvic wall, moves out via lesser sciatic foramen

Question 3

What is the pathway of the pelvic fascia?

Answer 3

Lines surface of obturator interns and follows it down to bony attachment, thickens in the middle to form tendinous arch

Question 4

What is found in the tendinous arch?

Answer 4

Attachment for levator ani

Question 5

What is the function of levator ani?

Answer 5

Separated pelvis and perineum, pressure maintenance, continence, support pelvic viscera, increase intra-abdominal pressure

Question 6

What is present between levator ani and obturator internus?

Answer 6

Pudendal/olcax canal - passage for NVB supplying pelvic floor

Question 7

What viscera lies over the obturator nerve?

Answer 7

Ovary

Question 8

What is formed in the middle of the pelvic floor and what is its function?

Answer 8

Raphe - site for muscle attachment

Question 9

What structures pierce levator ani?

Answer 9

Vagina, urethra, rectum

Question 10

What are the 3 muscles that made up levator ani?

Answer 10

Pubococccygeus, iliococcygeus, coccygeus

Question 11

What are the features of puborectalis?

Answer 11

• Inferior to pubococcygeus
• Maintains fecal continence
• Under reflex control as a child and as nervous system develops we take voluntary control
• At rest these fibres kink rectum towards pubis
• Merges with deep part of external anal sphincter

Question 12

Where does coccygeus attach?

Answer 12

Ischial spine, muscle on pelvic side and sacrotuberous ligament on perineal side

Question 13

When is the pelvic floor under high pressure?

Answer 13

Post partum

Question 14

What is the midline fibrous nodule in the perineum and what is its function?

Answer 14

Perineal body - muscle fibres merge here to stabilise the pelvic floor

Question 15

What is the nerve supply for the pelvic floor?

Answer 15

Segmental supply via S3-4 from above and pudendal nerve below S2-3

Question 16

Why is the nerve supply above the pelvic floor less dense than below?

Answer 16

Reduced susceptibility to entrapment, irritation

Question 17

What is the pathway of the pudendal nerve?

Answer 17

Moves into gluteal region through greater sciatic foramen with gluteal artery and then quickly exits pelvis through lesser sciatic foramen – well protected unless there is trauma to the perineal region

Question 18

What is the key landmark of the pudendal nerve?

Answer 18

Ischial spine

Question 19

What happens to the uterus/bladder if there is weakness of the pelvic floor?

Answer 19

Prolapse of uterus through vagina or herniation of bladder into urethra

Question 20

What is cystocoele/urethrocoele?

Answer 20

Hernitation of bladder and urethra into anterior vaginal wall

Question 21

What is rectocele?

Answer 21

Herniation of rectum into posterior vaginal wall