Deep inguinal ring is an oval opening in the transversalis fascia (fascia lining the transversus abdominis muscle). It is the entrance to the inguinal canal and lies about half inch above the inguinal ligament near its midpoint. The margins of this ring give attachment to the internal spermatic fascia (in males) or the inner covering of the round ligament of uterus (in females).
Deep inguinal ring transmits the spermatic cord (in males) or the round ligament of the uterus (in females).
Shape and size of deep inguinal ring:
The deep inguinal ring is of an oval form, with its long axis being vertical. The size varies considerably in different subjects; however, it is much larger in males than in females.
Boundaries of deep inguinal ring:
- The ring is bounded above and laterally by the arched lower margin of transversalis fascia.
- Below and medially, it is bound by the inferior epigastric vessels.
Common frustration for medical students:
Medical students are commonly unable to observe the superficial and deep inguinal rings as open. It must be kept in mind that the external spermatic fascia is attached to the margins of superficial inguinal ring and the internal spermatic fascia is attached to the margins of deep inguinal ring. Due to this, the edges of the rings cannot be observed as holes or openings. Compare this arrangement with the openings for the fingers when the glove is viewed from the outside.