The internal surface of anterior abdominal wall

In the midline, there are elevations of peritoneum with free edges, called folds.

Superior to the umbilicus:

  • A median fold, the falciform ligament. This contains the ligamentum teres, the obliterated umbilical vein. Note that the umbilical vein is patent for sometime after birth and may be used for exchange transfusion.

Inferior to the umbilicus, there are 5 folds:

  • The median umbilical fold is due to median umbilical ligament, the remnant of the urachus, which develops from the allantois. It attaches to the urinary bladder.

  • 2 medial umbilical folds formed by medial umbilical ligaments – the obliterated umbilical arteries.
  • 2 lateral umbilical folds – formed by the inferior epigastric vessels
   

The inguinal canal

Canal represents path taken by testis out of the abdomen.

Boundaries

Floor: Inguinal ligament and lacunar ligament

Roof: 		Arching fibres of internal oblique and transversus abdominis.
Antero lateral: Aponeurosis of external oblique
Posterior: Fascia transversalis laterally and conjoint tendon medially (of transversus and internal oblique abdominal muscles)

Contents

  • Spermatic cord in male
  • Round ligament of uterus in female and its artery
  • Ilioinguinal nerve

It may contain:

  • Iliohypogastric nerve
  • Genitofemoral nerve (genital branch)
  • Subcostal (in the upper part)
 

Inguinal Rings

  • Superficial ring is a triangular aperture in the aponeurosis of the external oblique muscle.

    (+) Base: pubic crest
    (+) Sides: crura of the external oblique aponeurosis.

  • The deep ring is a deficit in transversalis fascia, lateral to inferior epigastric artery.
 

 
Anterior Abdominal Wall and the Peritoneum