Pelvic Contents

Question 1

Label

Answer 1

Question 2

Label

Answer 2

Question 3

Label Sacrum

Answer 3

5x vertebrae fused
4x paired foramen (nerve passage)

Question 4

Label posterior sacrum

Answer 4

Question 5

What makes up the pelvic inlet. What is this the boundary of?

Answer 5

• Sacral promontory
• Alae of sacrum
• Arcuate line
• Pectineal line
• Pubic tubercle
• Pubic Crest
• Pubic symphysis

Above this= false pelvis
Below this= true pelvis

Question 6

Describe the ‘Pelvic Tilt’

Answer 6

~60 degree tilt anteriorly.

ASIS in line with Pubic tubercle

(sacrum also tilted)

Question 7

What are the pelvic boundaries?

Answer 7

Ant, Post and Lat = bone

Floor = muscular (pelvic diaphragm)

Question 8

Male/female variation of the pelvis

Answer 8

Question 9

What forms the greater and lesser sciatic foramen?

Answer 9

Sacrospinous and sacrotuberous ligaments

Question 10

Other ligaments of the pelvis?

Answer 10

Posterior sacroiliac ligament: fibrous (for strength)

Anterior sacroiliac ligament: synovial

Pubic symphysis

Question 11

Muscles of the pelvic wall

Answer 11

Piriformus and Obturator Internus

OI: fills entire obturator foramen except obturator canal, has 90 degree bend

Question 12

Draw out the vessel passages through the greater and lesser sciatic foramen.

Answer 12

Question 13

Journey of Pudendal Nerve and vessel

Answer 13

Leave through Greater sciatic foramen, loop under and around sacrospinous ligament and re-enter below pelvic floor into perineum

Question 14

Label nerves. Why do we need to know where these are?

Answer 14

Superior Gluteal Nerve: at risk during lateral approach to surgery

Sciatic Nerve: at risk during intramuscular injection

Question 15

Draw the branching of the anterior division!

Answer 15

Don’t learn the pattern!!

Question 16

Male/female differences of the anterior division of the internal iliac

Answer 16

Male: inferior vesical + middle rectal supply prostatem seminal vesicles and ductus deferens.
Testicular arteries from abdo aorta @L2

Female: uterine artery gives off vaginal artery (supplies femal genitalia)

Question 17

Draw branches of the posterior division

Answer 17

To superior gluteal → GSF above piriformis

Question 18

Venous drainage of the pelvis (EASY)

Answer 18

ALL draining to the Internal Iliac Veins

Exception: Deep dorsal vein of the penis/clitoris, drsins through deficiency in perineal membrane → vesical/prostatic plexuses

Question 19

The sacral plexus

Answer 19

S1-4 is joined by L4-5 (lumbrosacral trunk), although it’s mostly going to structures external of the pelvis, some are important!

• Gluteal Nerves
• Sciatic Nerves
• Nerves to Levator Ani and Coccygeus
• Pudendal Nerves

Question 20

Gluteal Nerves

Answer 20

Superior Gluteal (L4,L5,S1): to gluteus medius and minimus

Inferior Gluteal (L5,S1,S2): to gluteus maximus

Passing above and below piriformis

Question 21

Sciatic Nerves

Answer 21

L4-S3

Tibial always leaves below piriformis

Common peroneal can be above, below or thorugh

Question 22

Nerves to Levator Ani (direct S3-4) and Coccygeus

Answer 22

• Direct branches of sacral plexus
• Lie atop muscle → risk of damage → risk of prolapse

Question 23

Pudendal Nerve

Answer 23

“S2,3,4 keeps the penis off the floor

• Supplies everything in perineum (M and S)

Question 24

Branches of the Pudendal Nerve

Answer 24

• Inferior rectal
• Perineal
• DOrsal nere to clitoris/penis
• Scrotal/labial

Question 25

2 Plexuses of the ANS to the pelvic Viscera

Answer 25

1. Superior Hypogastric : Sits on anterior body of L5 and sacral
2. Inferior Hypogastric: on pelvic Floor (compression risk!)

Question 26

Sympathetic supply to pelvic viscera

Answer 26

L1/2 fibres descends into pelvis via Sup. hypogastric and sacral splanchnic. Splits to form two big right and left hypogastric nerves

• Contract int urethral and anal sphincters (continence)
• Ejaculation
• Moves secretions along epididymis

Question 27

Parasympathetic supply via pelvic viscera

Answer 27

S2-4, ascend via HG nerves → sup. hypogastric plexus → abdomen

Direct into Inf. HG

• Vasodilation (for erection)
• Bladder contraction