The sacral spinal nerve 3 (S3) is a spinal nerve of the

sacral segment The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal ...

.American Medical Association
Nervous System -- Groups of Nerves It originates from the spinal column from below the 3rd body of the sacrum. Gray95

Muscles

S3 supplies many muscles, either directly or through nerves originating from S3. They are not innervated with S3 as single origin, but partly by S3 and partly by other spinal nerves. The muscles are: * iliococcygeus *

puborectalis The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis. It is attached to the inner surface of each side of the ...

coccygeus The coccygeus muscle or ischiococcygeus is a muscle of the pelvic floor, located posterior to levator ani and anterior to the sacrospinous ligament. Structure The coccygeus muscle is posterior to levator ani and anterior to the sacrospinous li ...

sphincter urethrae membranaceae The urethral sphincters are two muscles used to control the exit of urine in the urinary bladder through the urethra. The two muscles are either the male or female external urethral sphincter and the internal urethral sphincter. When either of th ...

* superior gemellus

Additional Images

File:Slide20y.JPG, Sacral spinal nerve 3

References

Spinal nerves {{neuroanatomy-stub