Archive for inguinal canal

The Inguinal Canal and Groin Region (Notes by Konstantin Ravvin)

Posted in Medical Notes with tags , , , , , on March 26, 2016 by Konstantin

 

The inguinal canal is perhaps the most commonly encountered anatomical region in a medical student’s career.  It’s highly emphasized almost universally across all curriculums due to its distinction as a major hub for vascular and reproductive features as well as a major site for disease pathogenesis.  Please see the notes below:

Inguinal Region and Spermatic Cord

  • The fetal testes descending down the gubernaculum during embryonic development and descend into an outward picket of peritoneum called process vaginalis à ultimately ending up in the scrotum
  • The inguinal canal is the path that the testes follow out of the abdomen which lies parallel to the inguinal ligament. It is formed from a fold f the external oblique fascia and contains
    • Males: spermatic cord
      • Contains: ductus deferens + artery, testicular artery, pampiniform venous plexus
      • Clinical Note: The left teste is always lower than the right due to differences in venous flowout of the right and left kidney. A left teste that hangs too low may indicate a problem with kidney
    • Females: round ligament of uterus
  • The openings of the inguinal canal are:
    • Internal: deep ring
    • External: superficial ring
  • The walls of the inguinal canal
    • Posterior: fascia transversalis
      • Conjoint tendon: merger between aponeuroses of internal oblique and transverse abdominus
    • Anterior: external oblique aponeurosis
    • Roof: fascia trasnversalis and abdominal muscles
    • Floor: iliopubic tract, inguinal ligament, lacunar ligament
  • Muscles that move testes
    • Dartos Muscle is a smooth muscle that contracts to move the testes
    • External spermatic fascia is a continuation of the external oblique muscle
    • Cremaster muscle is a skeletal muscle that contracts tomovethe testes up. It is the continuation of the internal oblique. Innervated by ilioinguinal nerve.
  • Tunica vaginalis is the extension of the peritoneum into the testes
  • Sensory innervation isprovided by the genitofemoral nerve.
  • Clinical Note: In children, hernia most often involved the inguinal canal because it is weaker than the rest of the abdomen. In adults, they can happen anywhere
    • Indirect hernia: a protrusion within spermatic cord into scrotum in the lateral region of inguinal canal.
    • Direct hernia: an abdominal organ pushes out through the inguinal canal, but NOT through spermatic cord in the medial region of the spermatic cord.

Konstantin Ravvin