function

Last reviewed 08/2021

The inguinal canal is an area of potential weakness of the abdominal wall. Herniation of abdominal contents through the canal is minimised by:

  • the eccentricity of the superficial and deep rings:
    • due to the obliquity of the canal, the two rings do not coincide in position
    • any increase in intra-abdominal pressure forces the posterior wall against the anterior wall, so compressing the contents of the canal in the manner of a flap valve; this would not be possible if the rings were in alignment
  • contraction of the muscles within the canal:
    • approximates the anterior and posterior walls of the canal
    • lowers the roof of the canal: the specific action of transversus abdominis and internal oblique inserting into the conjoint tendon
    • tonic contraction on standing
    • increased reflex contraction on coughing or straining