Vessels and nerves in the pelvis. The pelvic floor.

Question 1

At what vertebral level does the bifurcation of the aorta into the common iliac arteries occur?

Answer 1

L4

Question 2

What vessel anastamoses with the inferior epigastric artery?

Answer 2

Superior epigastric.

Question 3

Aside from the internal iliac, what other arteries supply structures in the pelvis?

Answer 3

Gonadal (see previous deck), median sacral- from posterior surface of AA just superior to bifurcation, courses along anterior surface of sacrum and coccyx, anastamoses with shit…

Question 4

What are the possible branches of the internal iliac and what do they supply?

Answer 4

Superior vesical - bladder, inferior vesical (males) - bladder, uterine (females), vaginal (females) - vagina and base of bladder, middle rectal - debate about what it supplies and only present in 60%, obdurator - leg muscles, gluteal arteries - gluteal muscles.

Question 5

What forms the median umbilical ligament?

Answer 5

Remnant of the embryonic urachus.

Question 6

What forms the medial umbilical ligament?

Answer 6

Remnant of the umbilical artery.

Question 7

What is the lateral umbilical ligament?

Answer 7

Contains the epigastric vessels.

Question 8

Aside from the bladder, what does the inferior vesical artery of the male also supply?

Answer 8

Pelvic ureter, prostate, seminal glands, sometimes ductus deferens.

Question 9

Which branches of the internal iliac pass out of the pelvis and what do they supply?

Answer 9

Obturator - head of femur, muscles of medial compartment of thigh. Internal pudendal - exits pelvis via infrapubic part of greater sciatic foramen, enters perineum via lesser sciatic foramen, main artery of perineum. Gluteal arteries, exit via greater sciatic foramen, supplies pelvic wall and gluteal region.

Question 10

Most pelvic veins drain into the interal iliac veins. What is an exception to this?

Answer 10

Gonadal veins. R drains directly into IVC, L drains into L renal vein.

Question 11

Into where does most of the lymph from the pelvic viscera drain?

Answer 11

Internal iliac lymph nodes.

Question 12

Where do the internal iliac lymph nodes drain to?

Answer 12

Common iliac nodes.

Question 13

Into which nodes do the gonads drain?

Answer 13

Para-aortic nodes.

Question 14

Nerves present in the pelvis are:

Answer 14

Obturator, sacral plexus and sympathetic and parasympathetic autonomic nerves.

Question 15

What is the course of the obturator nerve?

Answer 15

Arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus. Descends through the fibers of the Psoas major, and emerges near the brim of the pelvis; then passes behind the common iliac arteries, on the lateral side of the internal iliac artery and ureter, runs along the lateral wall of the lesser pelvis behind the ovary, above and in front of the obturator vessels, to the upper part of the obturator foramen. Enters the thigh, through the obturator canal, and divides into an anterior and a posterior branch.

Question 16

From what is the sacral plexus formed?

Answer 16

Ventral rami of first four sacral nerves. Also receives contributions from ventral rami of fourth and fifth lumbar nerves.

Question 17

Of what is the pudendal nerve a branch?

Answer 17

Sacral plexus.

Question 18

Where does the pudendal nerve leave the pelvis?

Answer 18

Greater sciatic foramen.

Question 19

From where does the pelvis receive parasympathetic innervation?

Answer 19

Pelvic splanchnic nerves.

Question 20

From where do the pelvic splanchnic nerve arise?

Answer 20

Anterior rami of S2-4

Question 21

How are sympathetic fibres supplied to the pelvic viscera?

Answer 21

Thoracic and lumbar splanchnic nerves, which branch off the sympathetic chain and travel down into the pelvis via a number of midline plexuses.

Question 22

Where do the tendons of obturator internus and piriformis insert?

Answer 22

Greater trochanter of femur

Question 23

Where is the obturator canal? What runs through it?

Answer 23

The obturator canal is a passageway formed in the obturator foramen by part of the obturator membrane. It connects the pelvis to the thigh. The obturator artery, obturator vein, and obturator nerve all travel through the canal.

Question 24

Which muscles form levator ani?

Answer 24

Puborectalis Pubococcygeus Iliococcygeus

Question 25

Which muscles form the pelvic floor (pelvic diaphragm).

Answer 25

Levator ani and coccygeus.

Question 26

What are the attachments of levator ani?

Answer 26

Body of pubis, tendinous arch of obdurator fascia, ischial spine.

Question 27

What is the perianal body?

Answer 27

Central tendon of the perineum. Pyramidal, fibromuscular mass found in midline. Preserves intergrity of pelvic floor.

Question 28

What are the attachments of coccygeus?

Answer 28

Proximal - ischial spine. Distal - inferior end of sacrum and coccyx.

Question 29

Which bones make up the bony pelvis?

Answer 29

Ilium, ischium, sacrum and pubis.

Question 30

Which bony features define the pelvic brim?

Answer 30

Ala of sacrum, arcuate line, iliopubic eminence, pecten pubis, superior ramus of pubis.

Question 31

Which ligament runs between the ASIS and pubic tubercle?

Answer 31

Inguinal

Question 32

What is the lesser (or true) pelvis?

Answer 32

The space enclosed by the pelvic girdle and below the pelvic brim: between the pelvic inlet and the pelvic floor.

Question 33

What is the greater (or false) pelvis?

Answer 33

The greater pelvis is the space enclosed by the pelvic girdle above and in front of the pelvic brim