Anterior Abdominal Wall

Question 1

What are the bony landmarks of the abdominal wall?

Answer 1

Ribs and costal cartilages, transverse processes, ilium and iliac crest, pubic symphysis and rami, pubic tubercle, pecten pubis, anterior superior/inferior iliac spines, greater and lesser pelvis (lesser below pelvic inlet)

Question 2

What are the 4 transverse planes of the abdominal wall?

Answer 2

Transpyloric plane, subcostal plane, transtubercle plane and interspinous plane?

Question 3

What is the transpyloric plane?

Answer 3

At L1
Level of gall bladder fundus, pylorus, pancreatic neck, SMA origin, hepatic portal vein, root of transverse mesocolon and hila of kidneys

Question 4

What is the subcostal plane?

Answer 4

Passes inferior border of 10th costal cartilage at level of transverse colon
L3

Question 5

What is the transtubercle plane?

Answer 5

Between iliac tubercles
At level of ilocecal junction
L5

Question 6

What is the interspinous plane?

Answer 6

Between ASIS
At level of appendix and sigmoid colon
S2

Question 7

Describe the abdominopelvic cavity

Answer 7

Includes abdomen and pelvis
Between thoracic and pelvic diaphragm
Can extend as high as 4th intercostal space
Abdomen separated from pelvis by imaginary border of pelvic inlet (including the greater pelvis)
Walls mostly bone, muscle and CT
Lined by peritoneum

Question 8

What is camper’s fascia?

Answer 8

Fatty layer of superficial fascia

Question 9

What is Scarpa’s fascia?

Answer 9

Membranous underlying CT layer of superficial fascia
Continuous with Colle’s fascia of perineum but fused with fascia lata of lower limb
Fluid cannot go from abdominal wall into leg but could flow into or our of superficial perineum

Question 10

What is the rectus sheath?

Answer 10

Made of fascia and aponeurosis of muscles encompassing the rectus abdominus

Question 11

Describe how the abdominal musculature contributes to the rectus sheath

Answer 11

EO aponeurosis is always anterior
IO aponeurosis splits in upper 3/4 but is all anterior in lower 1/4 of the sheath
TA aponeurosis is posterior except in the lower 1/4 of the sheath

Question 12

What is the arcuate line?

Answer 12

The sharp transition where all EO, IO and TA aponeuroses become anterior to RA
So below the line the RA is in contact with the transversalis fascia (there is no posterior rectus sheath below the line)

Question 13

What are the nerves of the anterior abdominal wall?

Answer 13

Thoraco-abdominal nerves, subcostal nerves, Iliohypogastric nerve, ilioinguinal nerve

Question 14

What is the throaco-abdominal nerve?

Answer 14

T7-11
Continuation of intercostal nerves
Both motor and sensory innervation
Between IO and TA

Question 15

What is the subcostal nerve?

Answer 15

T12
Runs along inferior 12th rib
Motor
Sensory to superior to iliac crest

Question 16

What is the Iliohypogastric nerve?

Answer 16

L1
Runs between 2nd and 3rd muscle layers (IO and TA)
Motor to IO and TA
Sensory to upper inguinal and hypogastric region

Question 17

What is the ilioinguinal nerve?

Answer 17

L1
Motor to lower IO and TA
Sensory to lower inguinal, anterior scrotum/labia, near medial thigh

Question 18

Which arteries are located in the anterior abdominal wall?

Answer 18

Lumbar, superficial epigastric, superficial circumflex iliac, deep circumflex iliac, inferior epigastric, superior epigastric

Question 19

Which arteries of the abdominal wall come off the abdominal aorta?

Answer 19

Lumbar arteries

Question 20

Which arteries of the abdominal wall come off the femoral A?

Answer 20

Superficial epigastric, superficial circumflex iliac

Question 21

Which abdominal arteries come off the external iliac?

Answer 21

Deep circumflex iliac and inferior epigastric

Question 22

The superior epigastric A is a terminal branch of which A?

Answer 22

Internal thoracic A

Question 23

The superficial circumflex iliac A runs along what structure?

Answer 23

Along the inguinal ligament

Question 24

The deep circumflex artery runs deep to what structure?

Answer 24

Deep to inguinal ligament

Question 25

Where is the inferior epigastric A located and what does it anastomoses with?

Answer 25

Runs posterior to RA muscle

Anastomosis with superior epigastric A

Question 26

Superficial vessels superior to the umbilicus drain into what?

Answer 26

Axillary nodes with a few going to parasternal nodes

Question 27

Superficial vessels below the umbilicus drain to what?

Answer 27

Superficial inguinal LNs

Question 28

Deep lymph vessels accompany what?

Answer 28

Deep veins of abdominal wall (e.g. external and internal iliac veins)