Anatomy of Pelvis

Question 1

What artery is the main supply for the pelvic organs and perineum?

Answer 1

Internal iliac artery

Question 2

Where do the pubis, ilium and ischium all meet?

Answer 2

Acetabulum

Question 3

Where on the obturator membrane is the obturator canal which allows passage of neurovascular bundle?

Answer 3

Anterior superior aspect of obturator membrane

Question 4

The lateral aspect of the levator ani is attached to what?

Answer 4

Tendinous arch of levator ani

Question 5

The tendinous arch of levator ani is thickened fascia from which muscle?

Answer 5

Obturator internus muscle

Question 6

The tendon of which muscle passes through the lesser sciatic foramen?

Answer 6

Obturator internus

Question 7

The tendon of which muscle passes through the greater sciatic foramen?

Answer 7

Piriformis

Question 8

The piriformis is a landmark for what two nerves?

Answer 8

Is where gluteal nerve divides into superior and inferior and is also where sciatic nerve usually emerges inferior

Question 9

What are the two exceptions of the pelvic wall arteries that don’t arise from the internal iliac artery?

Answer 9

Gonadal artery (from abdo aorta at L2) and superior rectal artery (continuation of inferior mesenteric artery)

Question 10

The anterior division of the internal iliac artery is usually ______ and the posterior division is usually ______ in terms of the structures it supplies.

Answer 10

Anterior division is visceral and posterior division is parietal so body wall

Question 11

The medial umbilical ligament is a remnant of _______ which connected the ______ to the placenta through the umbilical cord.

Answer 11

remnant of umbilical artery which connected the internal iliac artery to the placenta

Question 12

What is a common variation of the gluteal arteries in relation to the posterior and anterior division of internal iliac artery?

Answer 12

Usually superior and gluteal arteries arise from posterior division on internal iliac however common variation is that inferior arises from anterior division

Question 13

List 6 important arteries that branch from the anterior division of internal iliac artery in female pelvis

Answer 13

superior vesical arteries, obturator artery, uterine artery and vaginal artery (branch from uterine), internal pudendal artery, middle rectal artery

Question 14

In the male pelvis what artery is homologous to the uterine artery in the female?

Answer 14

Artery to the vas deferens

Question 15

In the male pelvis what artery is there instead of vaginal artery?

Answer 15

Inferior vesical arteries - in females the vaginal artery gives off inferior vesical arteries so don’t need own one

Question 16

What are two important arterial anastamosis in the female pelvis?

Answer 16

Between uterine and vaginal artery at around cervix and vaginal wall and between uterine and ovarian artery

Question 17

Caution must be taken in hysterectomy to not damage which structure and why?

Answer 17

Ureter - water under the bridge because it crosses underneath the uterine artery

Question 18

What is vermiculation of ureter?

Answer 18

Ureter wiggles when you touch it so can differentiate it from arteries in surgery

Question 19

Iatrogenic damage to the ureter in females is more likely on which side? And why?

Answer 19

More likely on left side than right because left passes more medially

Question 20

List 3 (4) branches of the internal pudendal artery in females?

Answer 20

Inferior rectal artery, dorsal artery of clitoris, perineal artery which branch into labial arteries,

Question 21

There is contribution from which artery to the perineum?

Answer 21

External iliac artery contributes

Question 22

What branches do the inferior vesical arteries give off in the males? (2)

Answer 22

Artery to vas deferens and prostatic branch of inferior vesical artery

Question 23

What are 4 important branches of the internal pudendal artery in males?

Answer 23

Perineal artery, posterior scrotal artery, deep artery of penis and then dorsal artery of penis (this is the termination of internal pudendal)

Question 24

The anterior scrotal artery branches from what?

Answer 24

External iliac artery

Question 25

The venous drainage of the pelvis often follows the arterial system. What does it mainly drain into?

Answer 25

Internal iliac vein

Question 26

Other than internal iliac vein, list 2 other venous drainage sites and explain why they are clinically relevant?

Answer 26

Some will drain via superior rectal into hepatic portal system and some will drain via lateral sacral veins into internal vertebral venous plexus. Clinically relevant because provides alternate collateral pathway to superior or inferior vena cava and metastasis e.g. ovarian or prostatic cancer route to vertebral or cranial sites

Question 27

List 6 important nerves that lie on the lateral wall of the pelvis.

Answer 27

Obturator nerve (passes through), lumbosacral trunk, sciatic nerve, pudendal nerve, nerve to levator ani and pelvic splanchnic nerves

Question 28

What muscles does the sacral plexus of the lateral wall sit on?

Answer 28

Piriformis and coccygeus

Question 29

What is the route of the pudendal nerve?

Answer 29

S2,S3,S4 then goes out greater sciatic foramen, then loops around sacrospinous ligament and comes back into perineum via lesser sciatic foramen

Question 30

Nerve to levator ani is S ?

Answer 30

S3 S4

Question 31

Lumbosacral trunk contributes to ?

Answer 31

Sacral plexus

Question 32

Pelvic splanchnic nerves come from S?

Answer 32

S2, S3 and S4 anterior rami

Question 33

What is the pelvic splanchnic nerves modality?

Answer 33

Parasympathetic innervation

Question 34

Generally, the superior portion of pelvic viscera drain lymph where?

Answer 34

Into external iliac nodes -> common iliac -> aortic -> thoracic duct -> venous system

Question 35

Generally, the inferior portion of pelvic viscera and deep perineum drain lymph where?

Answer 35

Into internal iliac nodes -> common iliac -> aortic -> thoracic duct -> venous system

Question 36

Generally, where does superficial perineum drain lymph?

Answer 36

Superficial inguinal nodes

Question 37

Where do ovaries and testes generally drain lymph to and why?

Answer 37

Lumbar lymph nodes - aortic AKA caval because they originated on posterior abdominal wall

Question 38

What is trans-peritoneal spread?

Answer 38

Disease can penetrate through the peritoneal layer and disseminate into peritoneal cavity