D i.e. Inferior Epigastric Aery- Inguinal canal is an oblique intermuscular canalQ in anterior abdominal wall from deep to superficial inguinal rings. It contains (passes) spermatic cord in males, round ligament in females and ilioinguinal nerve in both sexesQ Constituents of spermatic cord include vas (ductus) deferens, aery of ductus deferens with autonomic sympathetic nerves around it; testicular aery, lymphatics and vein (pampiniform plexus); cremasteric aery & genital branch of genitofemoral nerveQ supplying cremasteric muscle; and remains of processes vaginalis.Round ligament is 10-12 cm long flattened band that is attached medially to upper pa of uterus, run in upper pa of broad ligament, enter deep inguinal ring, traverse inguinal canal before terminating in mons pubis above the labium majus. It contains blood vessels, nerves & lymphaticsQ. The lymphatics drain the uterine region around the entery of uterine tube to the superficial inguinal lymph nodes. Remains of processus vaginalis (projection of peritoneum) is carried with the round ligament for a sho distance into the inguinal canal in the fetus but is mostly obliterated in adults. In the inguinal canal the round ligament receives the same (but thinner) coverings as the spermatic cord, although being thinner they blend with ligament and may not reach mons pubis.Genital branch of genitofemoral nerve enters the inguinal canal by deep ring and supplies cremaster muscle and skin of scrotum in males. In females, it accompanies the round ligament and ends in the skin of mons pubis & labium majusQ (sensory supply)Superficial inguinal ring is a triangular hiatus (opening) in external oblique aponeurosis, just above & lateral (i.e. suprolateral) to pubic crest (Gray's)/ to pubicle tubercleQ (Moore).Inferior epigastric vessels neither pass through deep or superficial inguinal rings nor does it travel through inguinal canalQ. However, inferior epigastric vessels are impoant posterior relations of medial end of inguinal canal. They lie on fascia transversalis and ascend obliquely behind conjoint tendon into posterior poion of rectus sheath.Deep inguinal ring is an opening in fascia transversalis Q (& not in the transversalis abdominis). It is situated 1.25 cm or half an inch Q above mid inguinal point and pass spermatic cord in males &round ligaments in females Q (does not pass lilio-inguinal nerve).- Lacunar ligament along with inguinal ligament forms inferior wall (floor) not the posterior wall of inguinal canal. Posterior wall is formed by fascia transversalis and conjoint tendonQ.Triangle of Doom is bounded by gonadal vessels (lateral), vas deferens (medial), and peritoneal reflectionQ (base).