Walls and Floor of the Pelvis

Question 1

if viewed from the front what is the most anterior orifice of the pelvis?

Answer 1

The obturator Foramen

Question 2

What are the main 3 muscles that make up the floor of the pelvis?

Answer 2

Obturator Internus
*Levator Ani
Piriformis

Question 3

Obturator internus closes what wall of the pelvis?

Exits through what foramen?

Answer 3

Lateral

Lesser Sciatic Foramen with its gemeli

Question 4

What is the function of the elevator ani?

Answer 4

contraction and elevation of the anus

Question 5

through what foramen does the piriformis exits the pelvis?

Answer 5

Greater Sciatic Foramen

most posterior muscle

Question 6

Levator Ani can be subdivided into 3 main parts (which together form the pelvic diaphragm) this are?

Answer 6

Pubococcigeus
Iliococcigeus
Ischiococcigeus

Question 7

From where to where does the pelvic diaphragm extends?

Answer 7

from the posterior surface of the pubis to the ischial spine

Question 8

What does the pubococcigeal part of elevator ani do?

Answer 8

forms a hammock around the midline structures of the pelvis (pubovaginalis/puboprostaticus) and its most anterolateral fibres (arising from the top of Obturator Internus) form a hammock around the rectus (puborectalis)

Question 9

Iliococcigeus goes from…

Answer 9

linear attachment overlying obturator internus to the ischial spine.
its most anterior fibres are deep to the pubococcigeus
Raises the anal canal by pulling laterally

Question 10

the main function of ischiococcigeus is

Answer 10

None in humans

Wagging of the tail in animals

Question 11

above the pelvic diaphragm is the —1— and bellow the —-2—

Answer 11

1 Pelvis

2 Perineum

Question 12

What is the Perineal Flexure of the anal canal and in what circumstances must it be relaxed?

Answer 12

the puborectal fibres of the pubococcygeus muscle (bends the anal canal in 80 degrees posteriorly)
must be relaxed in order for defecation to occur

Question 13

what are the main subdivisions of the pelvic fascia?

Answer 13

Dense Fascia (immobile structures and lateral sides)
Loose Fascia (if the structures move)
Endopelvic Fascia (condensation of the loose fascia that condenses around the vessels that come from the periphery of the pelvis into the middle structures)

Question 14

What are the main nerve roots for the Sacral Plexus? what is it covered by and how does it exit the pelvis?

Answer 14

S1-S4 (some contribution from L4/L5)

arises onto piriform (covered by dense fascia), and leaves the pelvis with piriform by the greater sciatic foramen

Question 15

The internal iliac artery divides within the pelvis into branches how are these classified and what do they supply?

Answer 15

Anterior Division Fibres (for the pelvic organs in the middle line)
Posterior Division Fibres (parietal branches, for the walls of the pelvis and the gluteal region)

Question 16

because of the way the peritoneum reflects off the pelvic structures, in its most posterior part, there is the formation of a pouch what is its name? why is it relevant?

Answer 16

Recto-vesical Pouch (male)
Recto-uterine Pouch (female, pouch of Douglas)
if there is exudate in the peritoneum or any fluid this is where it will accumulate if the person is standing up

Question 17

in the female because of the uterus another pouch if formed, where is it located and what is its name?

Answer 17

Vesico-Uterine Pouch, anteriorly

between the bladder and the uterus