Everything Totally Explained


Ask & we'll explain, totally!
Sciatic nerve
Totally Explained


  NEW! All the latest news in the worlds of computer gaming, entertainment, the environment,  
finance, health, politics, science, stocks & shares, technology and much, much, more.  


View this entry using RSS

Everything about The Sciatic Nerve totally explained

The sciatic nerve (also known as the ischiatic nerve) is a large nerve that starts in the lower back and runs through the buttock and down the lower limb. It is the longest and largest single nerve in the 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.

Anatomical course

The nerve enters the lower limb by exiting the pelvis through the greater sciatic foramen, below the Piriformis muscle.
   It descends midway in the greater trochanter of the femur and the tuberosity of the ischium, and along the back of the thigh to about its lower third, where it divides into two large branches, the tibial and common peroneal nerves. This division may take place at any point between the sacral plexus and the lower third of the thigh. When it occurs at the plexus, the common peroneal nerve usually pierces the Piriformis muscles.
   In the upper part of its course, the nerve rests upon the posterior surface of the ischium, the nerve to the Quadratus femoris, the Obturator internus and Gemelli; it's accompanied by the posterior femoral cutaneous nerve and the inferior gluteal artery, and is covered by the Gluteus maximus.
   Lower down, it lies upon the Adductor magnus, and is crossed obliquely by the long head of the Biceps femoris.

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're 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's 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 (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 traditionally traces back to the Biblical account of Jacob being wounded when wrestling with the angel. The sciatic nerve is known in Hebrew as 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 are generally not sold as kosher.

    Additional images

    Image:Gray344.png|Structures surrounding right hip-joint. Image:Gray828.png|Plan of sacral and pudendal plexuses. Image:Gray832.png|Nerves of the right lower extremity Posterior view. Further Information

    Get more info on 'Sciatic Nerve'.


    External Link Exchanges

    Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:

      <a href="http://sciatic_nerve.totallyexplained.com">Sciatic nerve Totally Explained</a>

    Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
       As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned.



  • Copyright © 2007-8 totallyexplained.com | Licensed under the GNU Free Documentation License | Site Map
    This article contains text from the Wikipedia article Sciatic nerve (History) and is released under the GFDL | RSS Version