Boundaries of Inguinal Canal

Abdominal Swelling

• Causes: repeated pregnancies, hepatosplenomegaly, and ascites

Hernia Structure

• Consists of:
  • Sac: peritoneal pouch protruding through the defect and containing the protruded organ
  • Content: any abdominal viscera (mainly intestine and omentum) except the pancreas
  • Coverings: layers of abdominal wall

Inguinal Hernia

• Types:
  • Indirect (oblique)
  • Direct
• More common in males due to a wider and well-developed inguinal canal

Indirect Inguinal Hernia (Oblique Inguinal Hernia)

• Processus vaginalis remains open
• Common in young males
• Passes through the inguinal canal with an oblique passage
• Descends downward, forward, upward, and laterally
• Reduction occurs in the reverse direction

Femoral Hernia

• Clinical importance:
  • Femoral canal dead space for distension of femoral vein during muscular exercise
  • Pathway of lymph vessels from lower limb to abdomen
  • Pathway for femoral hernia (protrusion of a loop of intestine or omentum)
• More common in females due to a wider femoral ring and smaller femoral vein
• Neck of femoral hernia lies below and lateral to pubic tubercle

Inguinal Canal

• Boundaries:
  • Anterior wall: external oblique and internal oblique
  • Roof: internal oblique and transversus abdominis
  • Posterior wall: fascia transversalis and conjoint tendon
  • Floor: inguinal ligament
• Weak point: lateral half of the posterior wall formed only by fascia transversalis
• Contents:
  • Ilio-inguinal ligament
  • Round ligament of uterus
  • Ilio-inguinal nerve
  • Spermatic cord (vessels, nerves, lymphatics, and duct)

Spermatic Cord

• Coverings:
  • Internal spermatic fascia
  • Cremasteric fascia and muscle
  • External spermatic fascia
• Contents:
  • Three arteries (testicular, artery of vas deferens, and cremasteric)
  • Three nerves (cremasteric, ilioinguinal, and sympathetic plexus)
  • Three structures (vas deferens, pampiniform plexus of veins, and lymphatics)

Scrotum Layers

• From outwards to inwards:
  1. Skin
  2. Dartos muscle
  3. Membranous layer of the superficial fascia (Colle's fascia)
  4. External spermatic fascia
  5. Cremasteric muscle and fascia
  6. Internal spermatic fascia
  7. Parietal layer of tunica vaginalis

Mechanisms of Inguinal Canal

• Flap valve mechanism: compression of ant. and post. walls during intraabdominal pressure rise
• Shutter mechanism: contraction of internal oblique muscle to approximate roof and floor
• Contraction of external oblique muscle to approximate medial and lateral crura
• Ball valve mechanism: contraction of cremasteric muscle to elevate testis and plug superficial ring

Hernia Definition and Types

• Definition: protrusion of any abdominal viscus through a weak point of abdominal wall
• Types:
  • External hernia (appears on the surface): inguinal, femoral, umbilical, incisional
  • Internal hernia (does not appear on the surface): diaphragmatic hernia

Identify the structures that form the boundaries of the inguinal canal, including the anterior wall, roof, posterior wall, and floor. Test your knowledge of human anatomy and its details.