عصب شوكي

العصب: Spinal nerve
	The formation of the spinal nerve from the posterior and anterior roots
Latin	nervus spinalis

العصب الشوكي أو العصب النخاعي أو العصب الفقري (بالإنجليزية: Spinal nerves) هي الأعصاب الناشئة من النخاع الشوكي على عكس الأعصاب القحفية التي تنشأ من الدماغ. وتعتبر الأعصاب الشوكية جزء من الجهاز العصبي المحيطي.

يحوي جسم الإنسان على 31 زوج من الأعصاب الشوكية, حيث يخرج كل عصب شوكي من بين فقرتين في العمود الفقري.

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Structure

Spinal nerve

Typical spinal nerve location

Regional nerves

Cervical nerves

Lumbar nerves

Lumbar plexus and branches

The lumbar nerves are the five spinal nerves emerging from the lumbar vertebrae. They are divided into posterior and anterior divisions.

Posterior divisions: The medial branches of the posterior divisions of the lumbar nerves run close to the articular processes of the vertebrae and end in the multifidus muscle.

The laterals supply the erector spinae muscles.

Sacral nerves

Plan of sacral and pudendal plexuses

Function

Areas of distribution of the cutaneous branches of the posterior divisions of the spinal nerves. The areas of the medial branches are in black, those of the lateral in red

قالب:Actions by spinal nerves

Clinical significance

The muscles that one particular spinal root supplies are that nerve's myotome, and the dermatomes are the areas of sensory innervation on the skin for each spinal nerve. Lesions of one or more nerve roots result in typical patterns of neurologic defects (muscle weakness, abnormal sensation, changes in reflexes) that allow localization of the responsible lesion.

There are several procedures used in sacral nerve stimulation for the treatment of various related disorders.

Sciatica is generally caused by the compression of lumbar nerves L4, or L5 or sacral nerves S1, S2, or S3, or by compression of the sciatic nerve itself

صور اضافية

A portion of the spinal cord, showing its right lateral surface. The dura is opened and arranged to show the nerve roots.
Distribution of the cutaneous nerves. Ventral aspect.
Distribution of the cutaneous nerves. Dorsal aspect.
The spinal cord with dura cut open, showing the exits of the spinal nerves.
The spinal cord showing how the anterior and posterior roots join in the spinal nerves.
A longer view of the spinal cord.
Projections of the spinal cord into the nerves (red motor, blue sensory).
Projections of the spinal cord into the nerves (red motor, blue sensory).
Cervical plexus.gif

Schematic diagram of cervical plexus.

صور تشريح
Cerebrum. Inferior view. Deep dissection.
Cerebrum. Inferior view. Deep dissection.
Spinal nerves. Spinal cord and vertebral canal. Deep dissection.

المراجع

Blumenfeld H. 'Neuroanatomy Through Clinical Cases'. Sunderland, Mass: Sinauer Associates; 2002.
Drake RL, Vogl W, Mitchell AWM. 'Gray's Anatomy for Students'. New York: Elsevier; 2005:69-70.
Ropper AH, Samuels MA. 'Adams and Victor's Principles of Neurology'. Ninth Edition. New York: McGraw Hill; 2009.

العصب: Spinal nerve

The formation of the spinal nerve from the posterior and anterior roots
Latin	nervus spinalis