Abdominal Wall and Peritoneum

Anterior Abdominal Wall

skin, superficial fascia, subcutaneous fat, anterolateral and midline muscles, tranversalis fascia, extraperitoneal/ properitoneal fat, peritoneum

subcutaneous and properitoneal (absent in 18%) fat lines on AXR

Superficial Fascia

  • superficial layer = Camper’s fascia >superficial fascia of the thigh, Dartos fascia of scrotum
  • >deep layer = Scarpa’s fascia >external oblique aponeurosis, linea alba, symphysis pubis, underlying fascia of the thigh (=fascia lata), superficial perineal fascia (= Colles’ fascia)

Muscles and Ligaments

  • >rectus abdomini (5th-7thcostal cartilages ± xiphoid > lateral tendon [pubic tubercle ± pectin pubis], medial tendon [symphysis pubis])
    • >tendinous intersections of rectus abdominus @xiphoid, umbilicus and betw
    • >rectus sheath (P= superior and inferior epigastric vv)
    • >linea semilunaris (tip 9th costal cart > pubic tubercle, either side of rectus abdominis)
  • >linea alba
    • >adminiculum lineae albae (= deep fibres >triangle> pubic crest)
    • >pyramidalis (pubic body and symphysis > linea alba; anterior to rectus abdominis)
  • >external oblique (slips of 8 ribs > pubic crest, inguinal lig, anterior iliac crest and aponeurosis [> linea alba])
  • >internal oblique (inguinal lig, iliac crest, thoracolumbar fascia > lower 3rd-4th ribs, aponeurosis [>linea alba, split by rectus abdominus above arcuate line])
  • >arcuate line (below umbilicus)
  • >transversalis abdominis (inguinal lig, iliac crest, thoracolumbar fascia, lower 6 costal cart interdigitating with diaphragm > aponeurosis [post to rectus above arcuate line, anterior to rectus below])
  • >falx inguinalis = conjoint tendon (transversalis and internal oblique aponeurosis > crest and pectin pubis)
  • >inguinal ligament (ASIS>pubic tubercle; 12-14cm; cont with fascia lata)
  • >lacunar ligament = med/pectineal part of inguinal lig (> femoral ring)
  • >transversalis fascia (continuous with inferior diaphragmatic fascia, iliac and pelvic fascia, thoracolumbar fascia)
  • >median umbilical lig (remnant urachus fundus bladder > umbilicus, covered by peritoneum)
  • >medial umbilical ligaments (obliterated umbilical aa; superior vescial br internal iliac aa > umbilicus; covered by peritoneum)
  • >lateral umbilical ligaments = inferior epigastric aa and covering peritoneum (external iliac aa > rectus sheath)
  • >superior and inferior epigastric vessles run between rectus abdominus and posterior rectus sheath/transversalis fascia)

Inguinal Canal

  • >spermatic cord, round lig of uterus, ilioinguinal n
  • >superficial inguinal ring
  • >deep inguinal ring


  • >greater and lesser sacs
  • >lesser sac = omental bursa
  • >parietal and viseral layers lined by mesothelial cells

Peritoneal Spaces

  • >supramesocolic compartments separated by falciform ligament
  • >right supramesocolic space
    • >right subphrenic space (betw liver, right coronary lig, falciform lig, diaphragm)
    • >anterior right subhepatic space (post to porta hepatis, comm with foramen of Winslow)
    • >posterior right subhepatic space = hepatorenal fossa = Morison\’s pouch (betw liver and kidney; deepest point of abdominal cavity)
  • >left supramesocolic/subphrenic space
    • >immediate left subphrenic space (betw stomach, left triangular and coronary lig, diaphragm; gastrophrenic lig
    • >left subphrenic space = gastrohepatic recess (betw stomach and left liver)
    • >perisplenic space (partially separated from L paracolic by phrenicocolic lig)
  • >lesser sac = omental bursa
    • limited lateral by gastrosplenic and splenorenal lig
    • post wall: pancreas, L adrenal, UP L kidney
    • ant wall: stomach, leser omentum
    • paritially divided by pancreatogastric fold (L gastric a)
    • superior recess (betw caudate lobe, portal vein, fissure for lig venosum, gastropancreatic fold)
    • splenic recess (>splenic hilum)
    • inferior recess (betw stomach, pancreas, transverse mesocolon)
    • epiploic/omental foramen of Winslow (betw IVC, hepatoduodenal lig, caudate process, D1)
  • inframesocolic compartment
    • right inframesocolic space (betw transverse colon, SB mesentery)
    • left inframesocolic space (betw SB mesentery, sigmoid colon)
    • right > left paracolic gutters/spaces
  • pelvic peritoneal spaces
    • right and left paravesical spaces
    • prevesical space
    • rectovesical pouch (M)
    • uterovesical pouch
    • rectouterine pouch = pouch of Douglas (betw upper vagina, junction mid and lower thirds rectum)

Peritoneal Ligaments

  • right and left coronary and triangular ligaments
  • gastrophrenic lig (stomach > L diaphgram)
  • gastrosplenic lig (L gastroepiploic vessels, short gastric vessels)
  • falciform lig (ant to liver)
  • ligamentum teres = round lig (lower free border of falciform lig > posterior liver)
  • phrenicocolic lig (splenic flexure> diaphragm)
  • splenorenal lig (pancreatic tail, splenic hilum, distal pancreatic, splenic aa)
  • duodenocolic lig (betw hepatic flexure and descending duodenum; lymphatics from right colon)
  • median umbilical ligament/fold (urachus)
  • medial umbilical ligmanets (obliterated umbilical arteries)
  • lateral umbilical ligaments (inferior epigastric vessels)


  • greater omentum (folded double sheet; greater curve and duodenum >ant-sup transverse colon, L=gastrosplenic lig, mid=gastrocolic lig, R>duodenum)
    • gastrocolic lig (stomach > transverse colon; gastroepiploic a&v)
  • lesser omentum (lesser curve and 2cm duodenum > liver; gastric a, coronary v, left gastric nodal chain)
    • gastrohepatic lig (fissure for ligamentum venosum and medial liver>lesser curve; L fastric a&v, LNs)
    • hepatoduodenal lig (free edge hepatogastric lig; 1st&2nd duodenum> porta hepatis; portal triad)


  • small bowel mesentery (~15cm;, DJ flexure @ L2> SIJ)
  • transverse mesocolon (body to uncinate process pancreas)
  • sigmoid mesocolon (inverted V with left limb at left psoas, apex at L CIA bifurcation, right limb at S3; sigmoid and superior rectal vessels)
  • mesoappendix (lower end SB mesentery to tip appendix, sometimes suspends caecum)