Lecture 18 - Pelvic muscle and fascia

Question 1

The obturator foreamen is closed off by what?

Answer 1

obturator membrane - leaves only the obturator canal

Question 2

where are these 3 muscles located:

obturator internus

levator ani

piriformis

Answer 2

obturator internus - lateral wall

levator ani - pelvic floor

piriformis - posterior wall

Question 3

where does obturator internus arise from?

Answer 3

internal surface of obturator membrane - extends to the margins of the obturator foreamen

exits via the lesser sciatic foramen - converges and goes to the gluteal region

Question 4

Piriformis arises from the middle 3 pieces of the sacrum on the _____ surface

Answer 4

anterior surface of the middle 3 pieces

Question 5

where does piriformis exit?

Answer 5

via the greater sciatic foramen - heads for the greater trochanter

Question 6

levator ani is basically the..

Answer 6

pelvic floor

Question 7

levator ani is suspended from the side wall - what is its lateral origins (3 parts)

Answer 7

A thickening of the fascia overlying obturator internus

Question 8

With levator ani, there is a large opening _____ -_______to the region below called the perineum

Answer 8

There is a large opening antero-medially to the region below called the perineum

Question 9

half of obturator internus is above ___ ___

Answer 9

levator ani

other half is below in the perineum

Question 10

The rectum becomes the anal canal at the level of the ___ ___

Answer 10

pelvic floor - lev ant. interdigitate at the midline rafe, at the ano-rectal junction

Question 11

what are 2 componenets of levator ani?

Answer 11

pubicoccygeus

iliococcygeus

Question 12

pubicoccygeus arises from what?

Answer 12

pubic bone - most anterior part

Question 13

pubicoccygeus has a sling that extends where? whats it called?

why is it important?

Answer 13

from the pubic bone, around the anal- rectal junction and blends with the fibres of the ano-rectal junction

defacation can only ocur when puborectalis is relaxed

Question 14

In the male/female what is the most anterior slight for pubococcygeus?

Answer 14

pubo-prostaticus

Question 15

The non-slight parts of pubococcygeus (the hammock) is from where to where?

Answer 15

side wall of the pelvis and insert on the ano-coccygeal rafe - as we would expect from levator ani

Question 16

how is pubococcysegeus delineated from iliococcygeus?

Answer 16

pubococcysegeus is the ANTERIOR fibres, overlaps iliococcygeus when you look down on the pelvic floor

Pubo.c has the slights
ilio.c is a simple hammock

Question 17

iliococcygeus+pubococcysegeus =

Answer 17

LEVATOR ANI (LIFT THE ANUS)

Question 18

What muscle extends from the ishial spine to the coccyx/sacrum?

Answer 18

ishiococcygeus (ishio.c)

Question 19

What is the significance of ishiococcygeus ?

Answer 19

disappearing from the species - used to wag tail

not part of levator ani because its not functional in lifting the anus

Question 20

what are levatorani’s functions?

Answer 20

increasing intra abdomino-pelvic pressure alongside with the diaphragm - assists all evacuation processes/

To maintain and support the position of pelvic viscera

rotation during childbirth

Question 21

The parietal fascia is not as dense over which muscle in the pelvis, why?

Answer 21

levator ani - it has to lift up

Question 22

the parietal fascia of the pelvis is a continuation of the….

Answer 22

anterior abdominal wall (fascia transveraslis anteriorly, posterior ado. wall posteriorly)

Question 23

The visceral fascia in the pelvis is continuous with..

Answer 23

the extrperitoneal fat layer of the abdomen

Question 24

There are thickening (ligametns )visceral fascia around what in the pelvis?

Answer 24

vessels and nerves

condensation of visceral fascia - when they become engorged - create strong support

Question 25

The nerves and vessels are “glued to the muscle” by…

Answer 25

fascia

Question 26

Obturator nerves comes off the _____ _____ and now crosses the ______ _____and runs on the side wall, through the _____ canal

Answer 26

Obturator nerves comes off the lumbar plexus and now crosses the pelvic brim and running on the side wall, through the obturator canal

Question 27

What fascia does the obturator nerve supply?

Answer 27

parietal - pain referred to medial side of the thigh (just above the knee)

Question 28

The nerve supply to the peroneum is the

Answer 28

pudendal nerve - really imporatnt branch of the sacral plexus

Question 29

From the internal iliac artery there is what brancheds?

Answer 29

posterior and anterior branches - give give rise to parietal branches for the wall and visceral branches for the viscera