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
Peritoneum
- >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)
Omenta
- 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)
Mesenteries
- 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)