Aldridge - Structure Of Pelvic Wall

Question 1

Anterior-superior margin of vertebra S1

Answer 1

Sacral promontory

Question 2

Caudal most part of the vertebral canal

Contains cauda equina

Answer 2

Sacral canal

Question 3

Inferior opening to sacral canal

Potential site of needle entry for epidural anesthesia

Answer 3

Sacral hiatus

Question 4

The sacroiliac joint is held together by what ligaments?

Answer 4

Interosseous ligaments

Anterior and posterior sacroiliac ligaments

Question 5

Strong accessory ligament from transverse process of L5 to iliac crest

Answer 5

Iliolumbar ligament

Question 6

These two ligaments prevent the sacrum and coccyx from rotating posteriorly due to weight of trunk

Answer 6

Sacrotuberus

Sacrospinous ligaments

Question 7

Window for neuorvascular structures and piriformis muscles to pass from true pelvic region into the gluteal region

Answer 7

Great sciatic foramen

Question 8

Region for neurovascular structures and obturator internus muscle to pass from gluteal region to the perineum

Answer 8

Lesser sciatic foramen

Question 9

What structures make up the pelvic outlet? (X5)

Answer 9

Pubic symphysis

Ischial tuberosity

Tip of coccyx

Sacrotuberous ligament

Inferior ramus of pubis

Question 10

What is the diagonal conjugate diameter?

Answer 10

It is a measurement taken fro the inferior border of the pubic symphysis to the sacral promontory

Measures anterior-posterior diameter of the birth canal

Question 11

What is the transverse diameter of the pelvic outlet?

Answer 11

Measurement of the birth canal taken between the two ischial tuberosities

Question 12

What is the maximal measurement of the pelvic inlet?

Answer 12

Its transverse diameter

Bc of baby’s head position during parturition

Question 13

What is the maximum measurement of the pelvic outlet?

Answer 13

Anteroposterior diameter

Question 14

During partuition, the head of the baby must rotate _____- degrees between pelvic inlet and outlet

Answer 14

90

Question 15

What forms the lateral wall of the true pelvis?

Answer 15

Innominate bone (below pelvic brim)

Obturator internus muscle (and fascia)

Sacrospinous and sacrotuberous ligament.

Question 16

What forms the anterior wall of the true pelvis?

Answer 16

Pubic symphysis

Bodies of pubic bone

Question 17

What forms the posterior wall of the true pelvis?

Answer 17

Piriformis muscle

Question 18

Region below pelvic diaphragm

Contains external genitalia and outlet of gut and urogenital system

Answer 18

Perineum

Question 19

What happens if you tear the perineal body (a small mass of CT in the pelvic diaphragmm that is a point of insertion for many muscles)

Answer 19

You can get prolapse

This structure is important in maintaining support of the pelvic viscera

Question 20

The sacral nerves emerge from the sacral canal via ______

Answer 20

Anterior sacral foramina

Question 21

Branches of the sacral plexus that exit the true pelvis thru the greater sciatic foramen (x4)

Answer 21

Superior gluteal nerve

Inferior gluteal nerve

Sciatic nerve

Posterior cutaneous nerve of thigh