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Atlas of Human Embryos Chapter   Figure

L-3 spinal ganglion, L-4 spinal ganglion, L-5 spinal nerve, S-1 ventral primary ramus, ala of sacrum, anal canal, anus, buttock, gluteus maximus muscle, gluteus medius muscle, gluteus minimus muscle, greater sciatic foramen, greater trochanter, ilium, intervertebral disc, ischial tuberosity, ischiorectal fossa, levator ani muscle, obturator externus muscle, obturator internus muscle, pelvic plexus, rectum, sacral plexus, sacro-iliac joint, sciatic nerve, sympathetic trunk

A section through the anus, anal canal, caudal part of the rectum and L-3 and L-4 spinal ganglia.

Observe:
1. The ischiorectal fossa lateral to the rectum and anal canal between the levator ani and obturator internus muscles.
2. The sympathetic trunk medial to the S-1 ventral primary ramus.
3. The sacral plexus between the rectum and the greater sciatic foramen.
4. The ala of the sacrum medial to the sacroiliac joint.
5. The gluteal muscles in the buttock.


Keywords: L-3 spinal ganglion, L-4 spinal ganglion, L-5 spinal nerve, S-1 ventral primary ramus, ala of sacrum, anal canal, anus, buttock, gluteus maximus muscle, gluteus medius muscle, gluteus minimus muscle, greater sciatic foramen, greater trochanter, ilium, intervertebral disc, ischial tuberosity, ischiorectal fossa, levator ani muscle, obturator externus muscle, obturator internus muscle, pelvic plexus, rectum, sacral plexus, sacro-iliac joint, sciatic nerve, sympathetic trunk

Source: Atlas of Human Embryos.