Lecture 13: Pelvic contents, nerves and vessels

Question 1

Bones and landmarks of the pevlis:

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

True vs false pelvis

Answer 4

• Everything above line in picture false pelvis (in abdomin)
• Everything below line in picture true pelvis (in pelvic cavity)

Question 5

What is the orientation of the pelvis?

Answer 5

• Pelvis is tilted forward at about 60 degrees such that the ASIS and the pubic tubercle

Question 6

What are the boundaries of the pelvic cavity?

Answer 6

• Walls = bones
• Floor = muscular diaphragm

Question 8

Differences between male and female pelvis?

Answer 8

Question 9

Ligaments of the pelvis

Answer 9

• Sacrotuberous ligament
• Sacrospinous ligament

Question 10

What do the ligaments of the pelvis form?

Answer 10

• Greater sciatic foramen - A
• Lesser sciatic foramen - B

Question 11

What are the muscles of the pelvic wall?

Answer 11

• Piriformus - passes through greater sciatic foramen
• Obturator internus - passes through the lesser sciatic foramen

Question 12

What are the vessel & nerve passages through the greater and lesser sciatic foramen?

Answer 12

Question 13

Main arteries of the pelvic cavity?

Answer 13

• Internal iliac
  
  • –> anterior
  • –> posterior

Question 14

Branches of the anterior division?

Answer 14

Question 15

Main branch of posterior division?

Answer 15

• Superior gluteal

Question 16

Venous drainage of the pelvic cavity?

Answer 16

• Rich venous plexsus around bladder, prostate, rectum. uterus, vagina
  
  • All drain to internal iliac vein
• Deep doral vein od the penis/clitoris drains into…???

Question 17

What are the inputs to the sacral plexus?

Answer 17

• L4-24
  
  • L4 + L5 is lambrosacral trunk

Question 18

What are the nerves of the sacral plexus?

Answer 18

• Superior gluteal - L4+L5+S1
  
  • Superior to piriformus
• Inferior gluteal - L5+S1+S2
  
  • inferior to piriformus
• Sciatic - L4 –> S3
  
  • Below piriformus
• Levator ani - S3+S4
  
  • Sits on top of pelic floor (hence at risk)
  • Motor to lev ani. + coccygeus
• Pudendal nerve - S2 + S3 + S4
  
  • Perineum
    
    • Inf. Rectal
    • Perineal
    • Dorsal nerve to Clitoris/Penis
    • Scrotal/Labial

Question 19

2 Plexuses of the ANS to the pelvic Viscera

Answer 19

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

Question 21

Sympathetic supply to pelvic viscera

Answer 21

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

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

Question 22

Parasympathetic supply via pelvic viscera

Answer 22

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

Direct into Inf. HG

• Vasodilation (for erection)
• Bladder contraction