sciatic nerve

Nerve: Sciatic nerve
Latin	nervus ischiadicus
Gray's	subject #213 960
Innervates	Lateral rotator group (except Piriformis and Quadratus femoris), Posterior compartment of thigh
From	lumbar plexus and sacral plexus: L4-S3
To	tibial nerve, common fibular nerve

The sciatic nerve (also known as the ischiatic nerve) is a large nerve in humans and other animals. It begins in the lower back and runs through the buttock and down the lower limb. It is the longest and widest single nerve in the human body.

The sciatic supplies nearly the whole of the skin of the leg, the muscles of the back of the thigh, and those of the leg and foot. It is derived from spinal nerves L4 through S3. It contains fibres from both the anterior and posterior divisions of the lumbosacral plexus.

Branches

The nerve gives off articular and muscular branches.

• The articular branches (rami articulares) arise from the upper part of the nerve and supply the hip-joint, perforating the posterior part of its capsule; they are sometimes derived from the sacral plexus.

• The muscular branches (rami musculares) are distributed to the following muscles of the lower limb: biceps femoris, semitendinosus, semimembranosus, and adductor magnus. The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic, while the other muscular branches arise from the tibial portion, as may be seen in those cases where there is a high division of the sciatic nerve.

The muscular branch eventually gives off the tibial nerve and common peroneal nerve, which innervates the muscles of the (lower) leg. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis (which is innervated by the peroneal nerve).

Pathology

Pain caused by a compression or irritation of the sciatic nerve by a problem in the lower back is called sciatica. Common causes of sciatica include the following low back conditions: spinal disc herniation, degenerative disc disease, spinal stenosis, and spondylolisthesis.

In religion

In the Jewish religion, consumption of the sciatic nerve is forbidden, even from otherwise kosher and properly slaughtered animals. This is based on the prohibition mentioned in the Biblical account (Genesis chapter 32) of Jacob being wounded while wrestling with an angel.^[1] The sciatic nerve is known in Hebrew as the gid hanasheh. The process of removing the sciatic nerve (as well as certain large blood vessels and forbidden fats) from the surrounding meat is known as nikkur, or "deveining." Since this is a difficult and delicate process, cuts from an animal's hindquarters (including the Filet mignon) are generally not sold as kosher.^[2]

Additional images

Structures surrounding right hip-joint.

Plan of sacral and pudendal plexuses.

Nerves of the right lower extremity Posterior view.

References

See also

• Sciatica
• Gid hanasheh — religious terminology, from Judaism

External links

• Duke Orthopedics sciatic_nerve
• MedlinePlus Image 19503
• pelvis at The Anatomy Lesson by Wesley Norman (Georgetown University) (pelvicnerves)
• glutealregion at The Anatomy Lesson by Wesley Norman (Georgetown University) (glutealner)
• Sciatic Nerve - Cell Centered Database

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.