Inguinal Canal

Description

1. Structure & Boundaries:
Location: Medial ½ of the inguinal ligament.
Direction: Downwards, forwards, and medially.
Openings: Deep inguinal ring (lateral, in transversalis fascia) and Superficial inguinal ring (medial, in external oblique aponeurosis).
Walls:
Anterior: External oblique aponeurosis (reinforced laterally by internal oblique).
Posterior: Transversalis fascia (reinforced medially by conjoint tendon).
Roof: Arched fibers of internal oblique and transversus abdominis.
Floor: Inguinal ligament (reinforced medially by lacunar ligament).
Protection: Internal oblique muscle provides 3 mechanisms (supporting deep ring front, superficial ring back, canal roof/shutter).
2. Contents:
Spermatic cord (males) / Round ligament (females).
Ilioinguinal nerve.
Genital branch of genitofemoral nerve (through deep ring).
Spermatic Cord Layers: External spermatic, cremasteric, internal spermatic fascia.
3. Clinical Significance – Hernias:
Indirect Inguinal Hernia:
Enters via deep ring, traverses canal, exits via superficial ring, may enter scrotum.
Lies lateral to inferior epigastric artery.
More common.
Direct Inguinal Hernia:
Pushes directly through posterior wall (Hesselbach’s triangle).
Does not enter scrotum.
Lies medial to inferior epigastric artery.
4. Related Anatomy (Testis/Spermatic Cord):
Testes descend from abdomen into scrotum via the canal prenatally, guided by the gubernaculum.
Spermatic cord contains:
3 Arteries: Testicular, cremasteric, artery to vas deferens.
3 Nerves: Genital branch of genitofemoral, sympathetic fibers, ilioinguinal nerve.
Vas deferens, pampiniform plexus, lymphatics.
Testicular lymph drains to lumbar/para-aortic nodes (not inguinal).
5. Clinical Relevance (Scrotal Swelling):
Inguinal Hernia (content in canal/scrotum).
Hydrocoele (fluid in tunica vaginalis).
Haematocoele (blood in tunica vaginalis).
Varicocoele (dilated pampiniform plexus veins – “bag of worms”, more common left).
Epididymitis (inflammation).