Anterior Abdominal Wall Flashcards
What are the bony landmarks of the abdominal wall?
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)
What are the 4 transverse planes of the abdominal wall?
Transpyloric plane, subcostal plane, transtubercle plane and interspinous plane?
What is the transpyloric plane?
At L1
Level of gall bladder fundus, pylorus, pancreatic neck, SMA origin, hepatic portal vein, root of transverse mesocolon and hila of kidneys
What is the subcostal plane?
Passes inferior border of 10th costal cartilage at level of transverse colon
L3
What is the transtubercle plane?
Between iliac tubercles
At level of ilocecal junction
L5
What is the interspinous plane?
Between ASIS
At level of appendix and sigmoid colon
S2
Describe the abdominopelvic cavity
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
What is camper’s fascia?
Fatty layer of superficial fascia
What is Scarpa’s fascia?
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
What is the rectus sheath?
Made of fascia and aponeurosis of muscles encompassing the rectus abdominus
Describe how the abdominal musculature contributes to the rectus sheath
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
What is the arcuate line?
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)
What are the nerves of the anterior abdominal wall?
Thoraco-abdominal nerves, subcostal nerves, Iliohypogastric nerve, ilioinguinal nerve
What is the throaco-abdominal nerve?
T7-11
Continuation of intercostal nerves
Both motor and sensory innervation
Between IO and TA
What is the subcostal nerve?
T12
Runs along inferior 12th rib
Motor
Sensory to superior to iliac crest
What is the Iliohypogastric nerve?
L1
Runs between 2nd and 3rd muscle layers (IO and TA)
Motor to IO and TA
Sensory to upper inguinal and hypogastric region
What is the ilioinguinal nerve?
L1
Motor to lower IO and TA
Sensory to lower inguinal, anterior scrotum/labia, near medial thigh
Which arteries are located in the anterior abdominal wall?
Lumbar, superficial epigastric, superficial circumflex iliac, deep circumflex iliac, inferior epigastric, superior epigastric
Which arteries of the abdominal wall come off the abdominal aorta?
Lumbar arteries
Which arteries of the abdominal wall come off the femoral A?
Superficial epigastric, superficial circumflex iliac
Which abdominal arteries come off the external iliac?
Deep circumflex iliac and inferior epigastric
The superior epigastric A is a terminal branch of which A?
Internal thoracic A
The superficial circumflex iliac A runs along what structure?
Along the inguinal ligament
The deep circumflex artery runs deep to what structure?
Deep to inguinal ligament
Where is the inferior epigastric A located and what does it anastomoses with?
Runs posterior to RA muscle
Anastomosis with superior epigastric A
Superficial vessels superior to the umbilicus drain into what?
Axillary nodes with a few going to parasternal nodes
Superficial vessels below the umbilicus drain to what?
Superficial inguinal LNs
Deep lymph vessels accompany what?
Deep veins of abdominal wall (e.g. external and internal iliac veins)
