The Inguinal Canal
The inguinal canal is an oblique passage through the lower abdominal wall, playing a critical role in the transmission of structures between the abdomen and the perineum.
Boundaries (Mnemonic: MALT)
| Wall | Structure |
|---|---|
| Anterior | External oblique aponeurosis. |
| Posterior | Transversalis fascia (and conjoint tendon). |
| Roof | Internal oblique and transversus abdominis muscle fibers. |
| Floor | Inguinal ligament (and lacunar ligament). |
Contents
- Males: Spermatic cord.
- Females: Round ligament of the uterus.
- Both: Ilioinguinal nerve (emerges through the superficial ring; note: it does not travel through the entire canal).
High-Yield Exam Pearl:
Differentiating hernia types:
• Direct Inguinal Hernia: Protrudes through the **Hesselbach triangle** (medial to inferior epigastric vessels) due to a weak posterior wall.
• Indirect Inguinal Hernia: Protrudes through the **deep inguinal ring** (lateral to inferior epigastric vessels) due to a patent processus vaginalis.