Nerve to obturator internus
Encyclopedia
The nerve to obturator internus is a nerve
that innervates the obturator internus and gemellus superior muscles.
. It arises from the ventral divisions of the fifth lumbar
and first and second sacral nerves
.
It leaves the pelvis through the greater sciatic foramen below the piriformis muscle, and gives off the branch to the gemellus superior, which enters the upper part of the posterior surface of the muscle.
It then crosses the ischial spine
, reenters the pelvis through the lesser sciatic foramen
, and pierces the pelvic surface of the obturator internus.
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
that innervates the obturator internus and gemellus superior muscles.
Course
The nerve to obturator internus originates in the sacral plexusSacral plexus
-External links:*...
. It arises from the ventral divisions of the fifth lumbar
Lumbar
In tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum ...
and first and second sacral nerves
Sacral nerves
The five sacral nerves emerge from the sacrum. Although the vertebral components of the sacrum are fused into a single bone, the sacral vertebrae are still used to number the sacral nerves....
.
It leaves the pelvis through the greater sciatic foramen below the piriformis muscle, and gives off the branch to the gemellus superior, which enters the upper part of the posterior surface of the muscle.
It then crosses the ischial spine
Ischial spine
From the posterior border of the body of the Ischium there extends backward a thin and pointed triangular eminence, the ischial spine, more or less elongated in different subjects.It can serve as a landmark in pudendal anesthesia.-Surfaces:...
, reenters the pelvis through the lesser sciatic foramen
Lesser sciatic foramen
An opening between the pelvis and the posterior thigh, the foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine.-Boundaries:...
, and pierces the pelvic surface of the obturator internus.
See also
- Obturator nerveObturator nerveThe obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves; the branch from the third is the largest, while that from the second is often very small.-Path:...
- Nerve to quadratus femorisNerve to quadratus femorisThe nerve to quadratus femoris is a nerve that provides innervation to the quadratus femoris and gemellus inferior muscles.-Course:The nerve to quadratus femoris is a sacral plexus nerve...