Deep inguinal ring

The deep inguinal ring (internal or deep abdominal ring, abdominal inguinal ring, internal inguinal ring) is the entrance to the inguinal canal.

Location
The surface anatomy of the point is disputed, but in a recent study it was found to be at a point between the mid-inguinal point (situated midway between the anterior superior iliac spine and the pubic symphysis) and the midpoint of the inguinal ligament. Traditionally either one of these 2 sites was claimed as its location.

Some sources state that it is at the layer of the transversalis fascia.

Shape
It is of an oval form, the long axis of the oval being vertical; it varies in size in different subjects, and is much larger in the male than in the female.

Boundaries
It is bounded, above and laterally, by the arched lower margin of the transversalis fascia; below and medially, by the inferior epigastric vessels.

Transmission
It transmits the spermatic cord in the male and the round ligament of the uterus in the female.

Extensions
From its circumference a thin funnel-shaped membrane, the infundibuliform fascia, is continued around the cord and testis, enclosing them in a distinct covering.