After completing this study unit you will be able to:
- Explain how the sacral plexus is formed.
- Identify the branches of the sacral plexus.
- Describe the supply areas of each of the branches.
The sacral plexus is a nerve network composed of the anterior rami of the spinal nerves L4-L5 (lumbosacral trunk) and spinal nerves S1-S4 which exit the vertebral column either through the lowest two intervertebral foramina or anterior sacral foramina. The plexus is located posterior to the internal iliac artery and vein and anterior to the piriformis muscle.
The numerous branches of the plexus can be divided into posterior branches, arising from the posterior divisions of the anterior rami, anterior branches, from the anterior division, and one terminal branch. The main function of the plexus is to innervate the majority of muscles of the hip and gluteal region, lower limbs, pelvis and perineum. Additionally, the sacral plexus provides sensory innervation to the lower limb except for the anterior, medial and lateral parts of the thigh. Due to its connection via the lumbosacral trunk, the sacral plexus is often described together with the lumbar plexus under a combined name lumbosacral plexus.
This video tutorial will provide you with an overview of the nerves contributing to the sacral plexus, which structures they supply and lastly some clinical information.
Take a quiz
Now that you have watched the video about the sacral plexus, you can test your knowledge by taking our quiz
If you want to challenge yourself even further, why not take a quiz on the nerves, vessels and lymphatics of the whole pelvis, which you can customize yourself down to a single term!
Explore each of the individual nerves you learned today in the gallery below:
Once you have browsed through the nerves, you can take a look at some of the main muscles innervated by the sacral plexus:
|Origin||L4, L5, S1, S2, S3, S4|
Anterior branches: Nerve to quadratus femoris, nerve to obturator internus, pudendal nerve, nerves to levator ani and coccygeus
Posterior branches: Nerve to piriformis, superior gluteal nerve, inferior gluteal nerve, posterior femoral cutaneous nerve, perforating cutaneous nerve, pelvic splanchnic nerves
Terminal branch: Sciatic nerve (divides into tibial and common fibular nerves)
|Function||Motor and sensory innervation to the posterior thigh, leg, foot and part of the pelvis|
|Mnemonic for main branches||
Superior gluteal nerve, inferior gluteal nerve, posterior cutaneous nerve of thigh, pudendal nerve, sciatic nerve (SIPPS)