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A spinal nerve is a
mixed nerve A nerve is an enclosed, cable-like bundle of fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the electro ...
, which carries motor, sensory, and autonomic signals between the
spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. It encloses the central canal of the spinal cord, which contain ...

spinal cord
and the body. In the
human body The human body is the structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently organ systems. They ensure homeostasis and the life, viabi ...

human body
there are 31 pairs of spinal nerves, one on each side of the
vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton Axial may refer to: * one of the describing relationships in an animal body * and submarine volcano off Oregon, USA * , a ghost town * In geometry: :* ...

vertebral column
. These are grouped into the corresponding
cervical
cervical
,
thoracic The thorax or chest is a part of the anatomy Anatomy (Greek ''anatomē'', 'dissection') is the branch of biology concerned with the study of the structure of organism In biology, an organism (from Ancient Greek, Greek: ὀργανι ...

thoracic
,
lumbar In tetrapod anatomy, lumbar is an adjective that means ''of or pertaining to the abdominal segment of the torso, between the diaphragm (anatomy), diaphragm and the sacrum.'' The lumbar region is sometimes referred to as the lower vertebral column ...

lumbar
, sacral and
coccygeal The coccyx (plural: ''coccyges'' or ''coccyxes''), commonly referred to as the tailbone, is the final segment of the vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral co ...
regions of the spine. There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the
peripheral nervous system The peripheral nervous system (PNS) is one of two components that make up the nervous system In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, ...
.


Structure

Each spinal nerve is a mixed nerve, formed from the combination of
nerve fibers A nerve is an enclosed, cable-like bundle of fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the electroc ...
from its
dorsal Dorsal (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Repu ...
and ventral roots. The dorsal root is the afferent sensory root and carries sensory information to the brain. The ventral root is the efferent motor root and carries motor information from the brain. The spinal nerve emerges from the spinal column through an opening (
intervertebral foramen The intervertebral foramen (also called neural foramen, and often abbreviated as IV foramen or IVF), is a foramen In anatomy Anatomy (Greek ''anatomē'', 'dissection') is the branch of biology concerned with the study of the structure ...
) between adjacent vertebrae. This is true for all spinal nerves except for the first spinal nerve pair (C1), which emerges between the
occipital bone The occipital bone () is a neurocranium, cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is Trapezoid, trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occi ...

occipital bone
and the
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(the first vertebra). Thus the cervical nerves are numbered by the vertebra below, except spinal nerve C8, which exists below vertebra C7 and above vertebra T1. The thoracic, lumbar, and sacral nerves are then numbered by the vertebra above. In the case of a
lumbarized
lumbarized
S1 vertebra (aka L6) or a
sacralized
sacralized
L5 vertebra, the nerves are typically still counted to L5 and the next nerve is S1. Outside the vertebral column, the nerve divides into branches. The
dorsal ramus Dorsal (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Repu ...
contains nerves that serve the posterior portions of the trunk carrying visceral motor, somatic motor, and somatic sensory information to and from the skin and muscles of the back ( epaxial muscles). The
ventral ramus The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there ar ...
contains nerves that serve the remaining anterior parts of the trunk and the upper and lower limbs ( hypaxial muscles) carrying visceral motor, somatic motor, and sensory information to and from the ventrolateral body surface, structures in the body wall, and the limbs. The meningeal branches (recurrent meningeal or sinuvertebral nerves) branch from the spinal nerve and re-enter the intervertebral foramen to serve the ligaments, dura, blood vessels, intervertebral discs, facet joints, and periosteum of the vertebrae. The
rami communicantes Ramus communicans (plural rami communicantes) is the Latin term used for a nerve which connects two other nerves, and can be translated as "communicating branch". Structure When used without further definition, it almost always refers to a commun ...
contain autonomic nerves that serve visceral functions carrying visceral motor and sensory information to and from the visceral organs. Some anterior rami merge with adjacent anterior rami to form a
nerve plexus A nerve plexus is a plexus (branching network) of intersecting nerves. A nerve plexus is composed of afferent and efferent fibers that arise from the merging of the anterior rami of spinal nerves and blood vessels. There are five spinal nerve plex ...
, a network of interconnecting nerves. Nerves emerging from a plexus contain fibers from various spinal nerves, which are now carried together to some target location. Major plexuses include the
cervical
cervical
,
brachial
brachial
,
lumbar In tetrapod anatomy, lumbar is an adjective that means ''of or pertaining to the abdominal segment of the torso, between the diaphragm (anatomy), diaphragm and the sacrum.'' The lumbar region is sometimes referred to as the lower vertebral column ...

lumbar
, and
sacral
sacral
plexuses.


Regional nerves


Cervical nerves

The cervical nerves are the spinal nerves from the cervical vertebrae in the
cervical segment The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. It encloses the central canal of the spinal cord, which contains ...
of the spinal cord. Although there are seven cervical vertebrae (C1-C7), there are eight cervical nerves C1C8. C1–C7 emerge above their corresponding vertebrae, while C8 emerges below the C7 vertebra. Everywhere else in the spine, the nerve emerges below the vertebra with the same name. The posterior distribution includes the
suboccipital nerve The suboccipital nerve (first cervical dorsal ramus) is the dorsal primary ramus of the first cervical nerve (C1). It exits the spinal cord between the human skull, skull and the first cervical vertebra, the Atlas (anatomy), atlas. It lies within ...
(C1), the
greater occipital nerve The greater occipital nerve is a nerve of the head. It is a spinal nerve, specifically the medial branch of the dorsal primary ramus of cervical spinal nerve 2. It arises from between the first and second cervical vertebrae, ascends, and then pass ...
(C2) and the third occipital nerve (C3). The anterior distribution includes the
cervical plexus The cervical plexus is a plexus A plexus (from the Latin for "braid") is a branching network of vessels or nerves. The vessels may be blood vessels (veins, capillaries) or lymphatic vessels. The nerves are typically Axon, axons outside the centr ...

cervical plexus
(C1-C4) and
brachial plexus The brachial plexus is a network () of nerves (formed by the anterior rami The ventral ramus (pl. ''rami'') (Latin for ''branch'') is the anterior division of a spinal nerve. The ventral rami supply the antero-lateral parts of the trunk (anatomy), ...

brachial plexus
(C5-T1). The cervical nerves innervate the
sternohyoid The sternohyoid muscle is a thin, narrow muscle attaching the hyoid bone The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone A bone is a Stiffness, rigid tissue (anatomy), tissue that constitutes part of the vertebrate sk ...
,
sternothyroid The sternothyroid muscle, or sternothyroideus, is an Infrahyoid muscles, infrahyoid muscle in the neck. It acts to depress the hyoid bone. It is below the sternohyoid muscle. It is shorter and wider than the sternohyoid. Structure The sternothyr ...
and
omohyoid muscle The omohyoid muscle is a muscle that depresses the hyoid. It is located in the front of the neck, and consists of two bellies separated by an intermediate tendon. The omohyoid muscle is proximally attached to the scapula and distally attached to t ...

omohyoid muscle
s. A loop of nerves called
ansa cervicalis The ansa cervicalis (or ansa hypoglossi in older literature) is a loop of nerve A nerve is an enclosed, cable-like bundle of nerve fibers called axon An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see American ...

ansa cervicalis
is part of the cervical plexus.


Thoracic nerves

The thoracic nerves are the twelve spinal nerves emerging from the thoracic vertebrae. Each thoracic nerve T1 -T12 originates from below each corresponding
thoracic vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebra (anatomy), vertebrae and they are intermediate in size be ...

thoracic vertebra
. Branches also exit the spine and go directly to the
paravertebral ganglia The sympathetic ganglia, or paravertebral ganglia are autonomic ganglia An autonomic ganglion is a cluster of nerve cell A neuron or nerve cell is an electrically excitable cell that communicates with other cells via specialized connection ...
of the
autonomic nervous system The autonomic nervous system (ANS), formerly the vegetative nervous system, is a division of the peripheral nervous system that supplies smooth muscle and glands, and thus influences the function of viscera, internal organs. The autonomic nervous ...

autonomic nervous system
where they are involved in the functions of organs and glands in the head, neck, thorax and abdomen. Anterior divisions: The
intercostal nerves The intercostal nerves are part of the somatic nervous system The somatic nervous system (SNS), or voluntary nervous system is the part of the peripheral nervous system The peripheral nervous system (PNS) is one of two components that make up ...
come from thoracic nerves T1-T11, and run between the ribs. At T2 and T3, further branches form the intercostobrachial nerve. The
subcostal nerve The subcostal nerve (anterior division of the twelfth thoracic nerve) is larger than the others. It runs along the lower border of the twelfth rib, often gives a communicating branch to the first lumbar nerve, and passes under the lateral lumbocosta ...
comes from nerve T12, and runs below the twelfth rib. Posterior divisions: The medial branches (ramus medialis) of the posterior branches of the upper six thoracic nerves run between the
semispinalis dorsi The semispinalis muscles are a group of three muscles belonging to the transversospinales. These are the semispinalis capitis, the semispinalis cervicis and the semispinalis thoracis. The semispinalis capitis (''complexus'') is situated at the upp ...

semispinalis dorsi
and
multifidus The multifidus (multifidus spinae : ''pl. multifidi'' ) muscle consists of a number of fleshy and tendinous Muscle fascicle, fasciculi, which fill up the groove on either side of the spinous processes of the vertebrae, from the sacrum to the Axis ( ...
, which they supply; they then pierce the
rhomboid Traditionally, in two-dimensional geometry Geometry (from the grc, γεωμετρία; ' "earth", ' "measurement") is, with , one of the oldest branches of . It is concerned with properties of space that are related with distance, shape, ...
and
trapezius muscle The trapezius is a large paired surface muscle Muscle is a soft tissue found in most animals. Muscle cells contain protein Proteins are large biomolecules or macromolecules that are comprised of one or more long chains of amino acid ...
s, and reach the skin by the sides of the spinous processes. This sensitive branch is called the medial cutaneous ramus. The medial branches of the lower six are distributed chiefly to the multifidus and
longissimus dorsi The longissimus (Latin for 'the longest one') is the muscle lateral to the semispinalis muscles. It is the longest subdivision of the erector spinae muscles that extends forward into the transverse processes In the vertebrate spinal column, ea ...
, occasionally they give off filaments to the skin near the middle line. This sensitive branch is called the posterior cutaneous ramus.


Lumbar nerves

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 multifidus (multifidus spinae : ''pl. multifidi'' ) muscle consists of a number of fleshy and tendinous fasciculi, which fill up the groove on either side of the spinous processes of the vertebrae In the vertebrate spinal column, each vert ...
. The laterals supply the
erector spinae muscles The erector spinae ( ) or spinal erectors is a set of muscles that straighten and rotate the human back, back. Structure The erector spinae is not just one muscle, but a group of muscles and tendons which run more or less the length of the spine o ...
. The upper three give off cutaneous nerves which pierce the aponeurosis of the
latissimus dorsi The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius The trapezius is a large paired trapezoid In Euclidean geometry, a Convex polygon, convex ...

latissimus dorsi
at the lateral border of the erector spinae muscles, and descend across the posterior part of the iliac crest to the skin of the
buttock The buttocks (singular: buttock) are two rounded portions of the exterior anatomy of most mammals Mammals (from Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European l ...
, some of their twigs running as far as the level of the
greater trochanter The greater trochanter of the femur is a large, irregular, quadrilateral eminence and a part of the skeletal system. It is directed lateral and medially and slightly posterior. In the adult it is about 2-4 cm lower than the femoral head.Stand ...
. Anterior divisions: The anterior divisions of the lumbar nerves (rami anteriores) increase in size from above downward. They are joined, near their origins, by
gray rami communicantes Each spinal nerve receives a branch called a gray ramus communicans (plural rami communicantes) from the adjacent paravertebral ganglion of the sympathetic trunk. The gray rami communicantes contain postganglionic nerve fibers of the sympathetic ner ...
from the
lumbar ganglia The lumbar ganglia are paravertebral ganglia Along the length of the sympathetic trunks are ganglia known as ganglia of sympathetic trunk, sympathetic ganglia or paravertebral ganglia. The ganglia are distinguished as cervical, thoracic, lumb ...
of the
sympathetic trunk The sympathetic trunks (sympathetic chain, gangliated cord) are a paired bundle of nerve fibers that run from the base of the skull The skull is a bone A bone is a rigid tissue Tissue may refer to: Biology * Tissue (biology), an ensemb ...

sympathetic trunk
. These rami consist of long, slender branches which accompany the
lumbar arteries The lumbar arteries are arteries An artery (plural arteries) () is a blood vessel that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are ...
around the sides of the vertebral bodies, beneath the
psoas major The psoas major ( or ) is a long fusiform muscle Muscles are described using unique anatomical terminology according to their actions and structure. Types There are three types of muscle tissue in the human body: skeletal, smooth, and cardiac ...

psoas major
. Their arrangement is somewhat irregular: one ganglion may give rami to two lumbar nerves, or one lumbar nerve may receive rami from two
ganglia A ganglion is a group of neuron cell bodies in the peripheral nervous system The peripheral nervous system (PNS) is one of two components that make up the nervous system In biology Biology is the natural science that studies li ...

ganglia
. The first and second, and sometimes the third and fourth lumbar nerves are each connected with the lumbar part of the sympathetic trunk by a
white ramus communicans The white ramus communicans (plural: rami communicantes) from Latin ramus (branch) and communicans (communicating) is the preganglionic sympathetic outflow nerve tract from the spinal cord. Each of the thoracic, and the first and second lumbar nerv ...
. The nerves pass obliquely outward behind the psoas major, or between its fasciculi, distributing filaments to it and the
quadratus lumborum The quadratus lumborum muscle, informally called the ''QL'', is a paired muscle of the left and right posterior abdominal wall. It is the deepest abdominal muscle, and commonly referred to as a back muscle. Each is irregular and quadrilateral in sha ...
. The first three and the greater part of the fourth are connected together in this situation by anastomotic loops, and form the
lumbar plexus The lumbar plexus is a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the Ventral ramus of spinal nerve, divisions of the first four lumbar nerves (L1-L4) and ...

lumbar plexus
. The smaller part of the fourth joins with the fifth to form the
lumbosacral trunk The lumbosacral trunk is nervous tissue that connects the lumbar plexus The lumbar plexus is a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the Ventral ramus ...
, which assists in the formation of the
sacral plexus In human anatomy, the sacral plexus is a nerve plexus which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis. It is part of the lumbosacral plexus and emerges from the lumbar vertebrae ...

sacral plexus
. The fourth nerve is named the
furcal nerve The furcal nerve (forked nerve) links the lumbar plexus The lumbar plexus is a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the Ventral ramus of spinal nerv ...
, from the fact that it is subdivided between the two plexuses.


Sacral nerves

The sacral nerves are the five pairs of spinal nerves which exit the
sacrum The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy The human body is the structure of a human being Humans (''Homo sapiens'') are the most abundant and widespread species In biology, a species is the basic unit ...

sacrum
at the lower end of the
vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton Axial may refer to: * one of the describing relationships in an animal body * and submarine volcano off Oregon, USA * , a ghost town * In geometry: :* ...

vertebral column
. The roots of these nerves begin inside the vertebral column at the level of the L1 vertebra, where the
cauda equina The cauda equina () is a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs, and the coccygeal nerve, all of which arise from the lumbar enlar ...
begins, and then descend into the sacrum. There are five paired sacral nerves, half of them arising through the sacrum on the left side and the other half on the right side. Each nerve emerges in two divisions: one division through the
anterior sacral foramina The sacrum (plural: ''sacra'' or ''sacrums''), in human body, human anatomy, is a large, triangular bone at the base of the vertebral column, spine that forms by the fusing of sacral vertebrae S1S5 between 18 and 30years of age. The sacrum situ ...
and the other division through the posterior sacral foramina. The nerves divide into branches and the branches from different nerves join with one another, some of them also joining with lumbar or coccygeal nerve branches. These anastomoses of nerves form the
sacral plexus In human anatomy, the sacral plexus is a nerve plexus which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis. It is part of the lumbosacral plexus and emerges from the lumbar vertebrae ...

sacral plexus
and the
lumbosacral plexus The anterior divisions of the lumbar nerve The lumbar nerves are the five pairs of spinal nerves A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body The ...
. The branches of these plexus give rise to nerves that supply much of the
hip In vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, ...

hip
,
thigh In Outline of human anatomy, human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the Human leg, lower limb. The single bone in the thigh is called the femur. This bone is very thick and strong ...

thigh
,
leg A leg is a weight-bearingIn orthopedics Orthopedic surgery or orthopedics, is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat muscul ...

leg
and
foot The foot (plural: feet) is an anatomical Anatomy (Greek ''anatomē'', 'dissection') is the branch of biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemis ...

foot
. The sacral nerves have both afferent and
efferent fibers Efferent nerve fibers refer to axonal projections that ''exit'' a particular region; as opposed to Afferent nerve fiber, afferent projections that ''arrive'' at the region. These terms have a slightly different meaning in the context of the peri ...
, thus they are responsible for part of the
sensory perception Perception (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the powe ...
and the movements of the lower extremities of the human body. From the S2, S3 and S4 arise the pudendal nerve and parasympathetic fibers whose electrical potential supply the
descending colon In the anatomy of humans and homologous primates, the descending colon is the part of the large intestine from the splenic flexure to the beginning of the sigmoid colon. The function of the descending colon in the digestive system is to store the r ...

descending colon
and
rectum The rectum is the final straight portion of the large intestine The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in vertebrates. Water is absorbed here and the re ...

rectum
,
urinary bladder The urinary bladder, or simply bladder, is a hollow Muscle, muscular organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a hollow distensible organ that sits on the pel ...
and genital organs. These pathways have both afferent and efferent fibers and, this way, they are responsible for conduction of sensory information from these pelvic organs to the
central nervous system The central nervous system (CNS) is the part of the nervous system In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecu ...

central nervous system
(CNS) and motor impulses from the CNS to the pelvis that control the movements of these pelvic organs.3. Human Neuroanatomy. Carpenter, Malcolm B. Baltimore : Williams & Wilkins Co., 1976 (7th ed)


Coccygeal nerve

The bilateral coccygeal nerves, Co, are the 31st pair of spinal nerves. It arises from the conus medullaris, and its ventral ramus helps form the
coccygeal plexus The coccygeal plexus is a plexus of nerves A nerve is an enclosed, cable-like bundle of nerve fibers called axon An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see American and British English spelling diffe ...
. It does not divide into a medial and lateral branch. Its fibers are distributed to the skin superficial and posterior to the
coccyx The coccyx (plural: ''coccyges'' or ''coccyxes''), commonly referred to as the tailbone, is the final segment of the vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton Axial may refer ...
bone via the anococcygeal nerve of the coccygeal nerve plexus.


Function


Clinical significance

The muscles that one particular spinal root supplies are that nerve's
myotome A myotome is the group of muscle Skeletal muscles (commonly referred to as muscles) are organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given or ...
, and the
dermatomes A dermatome is an area of skin that is mainly supplied by afferent nerve fibres from the dorsal root of spinal nerve, dorsal root of any given spinal nerve. There are 8 cervical nerves (C1 being an exception with no dermatome), 12 thoracic nerves ...
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 Muscle weakness is a lack of muscle Skeletal muscles (commonly referred to as muscles) are organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A gi ...
, 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 Sciatica is pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain The International Association for the Study of Pain (IASP) is an international learned society ...

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


Additional Images

File:Gray796.png, A portion of the spinal cord, showing its right lateral surface. The dura is opened and arranged to show the nerve roots. File:Gray797.png, Distribution of the cutaneous nerves. Ventral aspect. File:Gray798.png, Distribution of the cutaneous nerves. Dorsal aspect. File:Sobo 1909 611.png, The spinal cord with dura cut open, showing the exits of the spinal nerves. File:Sobo 1909 613.png, The spinal cord showing how the anterior and posterior roots join in the spinal nerves. File:Sobo 1909 614.png, A longer view of the spinal cord. File:Sobo 1909 615.png, Projections of the spinal cord into the nerves (red motor, blue sensory). File:Sobo 1909 616.png, Projections of the spinal cord into the nerves (red motor, blue sensory). File:Cervical plexus.gif, Schematic diagram of cervical plexus. File:Slide2PIT.JPG, Cerebrum. Inferior view. Deep dissection. File:Slide3PIT.JPG, Cerebrum. Inferior view. Deep dissection. File:Slide2VAS.JPG, Spinal nerves. Spinal cord and vertebral canal. Deep dissection.


See also

*
Cranial nerves Cranial nerves are the nerve A nerve is an enclosed, cable-like bundle of fibers (called axon An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, ...


References

* 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. {{Authority control Peripheral nervous system *