This nerve (N. obturatorius) is derived from the ventral branches of the
last three lumbar nerves (Fig. 524). It runs downward and backward, at
first above and then upon the external iliac vein, inclines inward
across the obturator vein, and passes through the anterior part of the
obturator foramen in front of that vessel (Fig. 451). It continues
downward through the obturator externus, and divides into several
branches which innervate the obturator externus, pectineus, adductor,
and gracilis muscles (Fig. 456).