The Spinal cord nested in the vertebral column.

A closer look.

Cross-section through cervical spinal cord.

Gray Matter's Vexed Lamina.

Somatosensory Tracts.

Spinal Cord Development of the Alar and Basal Plates

Spinal Cord Tracts

The spinal cord is a thin, tubular bundle of nerves that is an extension of the central nervous system from the brain and is enclosed in and protected by the bony vertebral column. The main function of the spinal cord is transmission of neural inputs between the periphery and the brain. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The vertebral column seen from the side The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ... Image File history File links Spinalcord_trirev. ... Image File history File links Spinalcord_trirev. ... Image File history File links Medulla_spinalis_-_Section_-_English. ... Image File history File links Medulla_spinalis_-_Section_-_English. ... Image File history File links Spinalcord_trirev_vexedlamina. ... Image File history File links Spinalcord_trirev_vexedlamina. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Nerves (yellow) Nerves redirects here. ... A diagram showing the CNS: 1. ... The vertebral column seen from the side The vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the abdomen. ... In animals, the brain or encephalon (Greek for in the head), is the control center of the central nervous system, responsible for behaviour. ...

Structure

The spinal cord extends from the medulla oblongata in the brain and continues to the conus medullaris near the lumbar level at L1-2, terminating in a fibrous extension known as the filum terminale. The spinal cord is about 45 cm long in men and 42 cm long in women, ovoid-shaped, and is enlarged in the cervical and lumbar regions. The peripheral regions of the cord contains neuronal white matter tracts containing sensory and motor neurons. The central region is a four-leaf clover shape that surrounds the central canal (an anatomic extension of the fourth ventricle) and contains nerve cell bodies. The three meninges that cover the spinal cord -- the outer dura mater, the arachnoid membrane, and the innermost pia mater -- are continuous with that in the brainstem and cerebral hemispheres, with cerebrospinal fluid found in the subarachnoid space. The cord within the pia mater is stabilized within the dura mater by the connecting denticulate ligaments which extends from the pia mater laterally between the dorsal and ventral roots. The dural sac ends at the vertebral level of S2. The medulla oblongata is the lower portion of the brainstem. ... The conus medullaris is the terminal end of the spinal cord. ... The spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). ... The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. ... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ... The dura mater (from the Latin hard mother), or pachymeninx, is the tough and inflexible outermost of the three layers of the meninges surrounding the brain. ... The Arachnoid mater is one of the three layers of the meninges, interposed between the dura mater and the pia mater and separated from the pia mater by the subarachnoid space. ... [www. ... Cerebrospinal fluid (CSF), Liquor cerebrospinalis, is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ... The meninges (singular meninx) are the system of membranes that contain the brain. ... The pia mater has 21 pairs of denticulate ligaments which attach it to the arachnoid and dura maters. ... [www. ...

Sensory Organization

Somatosensory organization is divided into a touch/proprioception/vibration sensory pathway and a pain/temperature sensory pathway, which are more formally known as the dorsal column-medial lemniscus tract and the spinothalamic tract, respectively. Each of these sensory pathways utilizes three different neurons to get from the sensory receptors to the cerebral cortex. These neurons are designated primary, secondary and tertiary sensory neurons. The primary neuron will have its cell body in the dorsal root ganglia and then its axon projects into the spinal cord. In the case of the touch/proprioception/vibration sensory pathway, the primary neuron enters the spinal cord and travels in the dorsal column. If the neuron enters below level T6, the neuron will travel in the fasciculus gracilis - the most medial part of the column. Above level T6, the neuron will enter the fasciculus cuneatus - lateral to the fasiculus gracilis. The primary axons reach the caudal medulla, they will leave their respective fasiculi and will enter and synapse on secondary neurons with the nucleus gracilis and the nucleus cuneatus, respectively. At this point, the seconday neuronal axons will decussate and will continue to ascend as the medial leminiscus. They will run all the way up to the VPL nucleus of the thalamus. They will synapse there on the tertiary neurons. From there, the tertiary neurons will ascend via the posterior limb of the internal capsule to the post central gyrus, or Brodmann's Area 3,1,2. // Proprioception (PRO-pree-o-SEP-shun (IPA pronunciation: ); from Latin proprius, meaning ones own and perception) is the sense of the relative position of neighbouring parts of the body. ... The posterior column-medial lemniscus pathway is the sensory pathway responsible for transmitting fine touch and conscious proprioceptive information from the body to the cerebral cortex. ... The spinothalamic tract is a sensory pathway originating in the spinal cord that transmits information about pain, temperature, itch and crude touch to the thalamus. ... Location of the cerebral cortex Slice of the cerebral cortex, ca. ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... The posterior column-medial lemniscus pathway (called the dorsal column in non-humans) is the sensory pathway responsible for transmitting discriminative sensation from the skin to the thalamus, and on to the cerebral cortex. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... The fasciculus cuneatus (tract of Burdach) is triangular on transverse section, and lies between the fasciculus gracilis and the posterior column, its base corresponding with the surface of the medulla spinalis. ... Medulla in general means the inner part, and derives from the Latin word for marrow. In medicine it is contrasted to the cortex. ... The swelling on the fasciculus gracilis is named the clava, and is produced by a subjacent nucleus of gray matter, the nucleus gracilis. ... Cuneate nucleus is a wedge-shaped nucleus in the medulla. ... The medial lemniscus, also known as Reils band or Reils ribbon, is a pathway in the brainstem, that carries sensory information from the gracile and cuneate nuclei to the thalamus. ... The ventral posterolateral nucleus (VPL) is a nucleus of the thalamus which projects to the postcentral gyrus and receives information from the medial lemniscus. ... The thalamus (from Greek θάλαμος = bedroom, chamber, IPA= /ˈθæləməs/) is a pair and symmetric part of the brain. ... The internal capsule is an area of white matter in the brain that separates the caudate nucleus and the thalamus from the lenticular nucleus. ... Korbinian Brodmann (November 17, 1868 - August 22, 1918) was a German neurologist who became famous for his definition of the cerebral cortex into 52 distinct regions from their cytoarchitectonic (histological) characteristics. ...

The pain/temperature sensory pathway differs from that of the touch/proprioception/vibration pathway. The pain neurons will enter as primary neurons and will ascend 1-2 levels before synapsing in the substantia gelatinosa. The tract that ascends those 1-2 levels before synapsing is known as Lissauer's tract. After synapsing, the secondary neurons will cross decussate and ascend as the spinothalamic tract in the anterior lateral portion of the spinal cord. Hence, the spinothalamic tract is also known as the anterior lateral system (ALS). The tract will ascend all the way to the VPL of the thalamus where it will synapse on the tertiary neurons. The tertiary neuronal axon will then project via the posterior limb of the internal capsule to the post-central gyrus or Broadmann's Area 3,1,2. Substantia gelatinosa can refer to: Substantia gelatinosa of Rolando Substantia gelatinosa centralis This is a disambiguation page: a list of articles associated with the same title. ... The posterolateral tract (fasciculus of Lissauer, tract of Lissauer, dorsolateral fasciculus) is a small strand situated in relation to the tip of the posterior column close to the entrance of the posterior nerve roots. ... The spinothalamic tract is a sensory pathway originating in the spinal cord that transmits information about pain, temperature, itch and crude touch to the thalamus. ... In the nervous system, the anterolateral system is an ascending pathway that conveys pain and temperature (protopathic sensation) from the periphery to the brain. ...

It should be noted that the pain fibers in the ALS can also deviate in their pathway towards the VPL. In one pathway, the axons can project towards the reticular formation in the midbrain. The reticular formation will then project to a number of places including the hippocampus (to create memories about the pain), to the centromedian nucleus (to cause diffuse, non-specific pain) and the various places on the cortex. The third place that the neurons can project to is the periaqueductal gray in the pons. The neurons form the periaqueductal gray will then project to the nucleus raphe magnus which then projects back down to where the pain signal is coming in from and inhibits it. This will reduce the pain sensation to some degree. The reticular formation is a part of the brain which is involved in stereotypical actions, such as walking, sleeping, and lying down. ... The hippocampus is structurally located inside the medial temporal lobe of the brain. ... In anatomy, the centromedian nucleus, also known as the centrum medianum, (CM or Cm-Pf) is a part of the intralaminar nucleus (ILN) of the thalamus. ... Periaqueductal gray (PAG; also called the central gray) is the midbrain grey matter that is located around the cerebral aqueduct within the midbrain. ... The nucleus raphe magnus, located directly rostral to the raphe obscurus, is afferently stimulated from axons in the spinal cord and cerebellum. ...

Motor Organization

Upper motor neuronal input comes from two places. The first is from the cerebral cortex and the second is from more primitive brainstem nuclei. Cortical upper motor neurons originate in Brodmann Areas 4, 6, 3, 1 and 2. They then descend through the genu and the posterior limb of the internal capsule. This pathway is known as the corticospinal tract. After passing through the internal capsule, the tract descends through the cerebral peduncles, down through the pons and to the medullary pyramids. At this point, ~85% of these upper motor neuronal axons decussate. These fibers then descend as the lateral corticospinal tract. The remaining ~15% descend as the anterior corticospinal tract.

The internal capsule is an area of white matter in the brain that separates the caudate nucleus and the thalamus from the lenticular nucleus. ... The corticospinal or pyramidal tract is a massive collection of axons that travel between the cerebral cortex of the brain and the spinal cord. ... The interior district of the medulla oblongata is named the pyramid and lies between the anterior median fissure and the antero-lateral sulcus. ...

The midbrain nuclei include four motor tracts that send upper motor neuronal axons down the spinal cord to lower motor neurons. These are the rubrospinal tract, the vestibulospinal tract, the tectospinal tract and the reticulospinal tract. The rubrospinal tract descends with the lateral corticospinal tract and the remaining three descend with the anterior corticospinal tract.

The rubrospinal tract is part of the indirect extra-pyramidal tract and is responsible for large muscle movement such as the arms and the legs. ... The vestibulospinal tract is one of the descending spinal tracts of the ventromedial pathway. ... The tectospinal tract is part of the indirect extrapyramidal tract and is responsible for coordinating head and eye movements, It is responsible for impulses that are motor. ... The reticulospinal tract (or anterior reticulospinal tract) is an extrapyramidal motor tract which travels from the reticular formation. ...

The function of lower motor neurons can be divided into two different groups. The first is the lateral corticospinal tract. This tract contains upper motor neuronal axons which then synapses on dorsal lateral (DL) lower motor neurons. The DL neurons are involved in distal limb control. This means that these lower motor neurons are involved in controlling motions of the limbs. Therefore, these DL neurons are found specifically only in the cervical and lumbosaccral enlargements within the spinal cord. There is no decussation in the lateral corticospinal tract after the decussation at the medullary pyramids.

An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, which conducts electrical impulses away from the neurons cell body or soma. ... In zootomy, several terms are used to describe the location of organs and other structures in the body of bilateral animals. ...

The anterior corticospinal tract descends down ipsilaterally in the anterior column where the axons will emerge and either synapse on lower motor neurons, known as ventromedial (VM) lower motor neurons, in the ventral horn in an ipsilateral fashion, or will descussate at the anterior white commissure where they will synapse on VM lower motor neurons in a contralateral fashion. The tectospinal, vestibulospinal and reticulospinal descend ipsilaterally in the anterior column, but do not synapse across the anterior white commissure. Rather, they only synapse on VM lower motor neurons ipsilaterally. The VM lower motor neurons control axial motor function. This means they are in charge of large, postural muscles. These lower motor neurons, unlike those of the DL, are located in the ventral horn all the way throughout the spinal cord. The anatomical planes The anatomical position is a schematic convention for describing the relative morphology of the human body. ... The Anterior Commissure (precommissure) is a bundle of white fibers, connecting the two cerebral hemispheres across the middle line, and placed in front of the columns of the fornix. ... It has been suggested that Human Anatomical Terms be merged into this article or section. ... Axial has different meanings: In geometry it means: along the same line as an axis (coaxial) or centerline: parallel (geometry), contrary to radial or perpendicular In anatomy it relates to an anatomical direction of animals and humans. ...

Spinocerebellar Tracts

The sense of proprioception in the body is sensed in the body and then travels up the spinal cord via three tracts. Below L2 the proprioceptive information travels up the spinal cord in the ventral spinocerebellar tract. Also known as the anterior spinocerebellar tract, sensory receptors take in the information and travel into the spinal cord. The cell bodies of these primary neurons are located in the dorsal root ganglia. In the spinal cord, the axons will synapse and the secondary neuronal axons will decussate and then travel up to the superior cerebellar peduncle where they decussate again. From here, the information is brought to deep nuclei of the cerebellum including the fastigial and interposed nuclei.
From the levels of L2 to T1, the proprioceptive information enters the spinal cord and ascends ipsilaterally where it synapses in the Dorsal Nucleus of Clark. The secondary neuronal axons continue to ascend ispilateraly and will enter the pass into the cerebellum via the inferior cerebellar peduncle. This tract is known as the dorsal spinocerebellar tract and also as the posterior spinocerebellar tract.
From above T1, proprioceptive primary axons enter the spinal cord and ascend ipsilaterally until reaching the accessory cuneate nucleus, where they synapse. The secondary axons pass into the cerebellum via the inferior cerebellar peduncle where again, these axons will synapse on cerebellar deep nuclei. This tract is known as the cuneocerebellar tract. // Proprioception (PRO-pree-o-SEP-shun (IPA pronunciation: ); from Latin proprius, meaning ones own and perception) is the sense of the relative position of neighbouring parts of the body. ... The ventral spinocerebellar tract conveys proprioceptive information from the body to the cerebellum. ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ... Figure 1a: A human brain, with the cerebellum in purple. ... The cerebellum (Latin: little brain) is a region of the brain that plays an important role in the integration of sensory perception and motor output. ... Figure 1a: A human brain, with the cerebellum in purple. ... The dorsal spinocerebellar tract (posterior spinocerebellar tract, Flechsigs fasciculus, Flechsigs tract) conveys proprioceptive information from the body to the cerebellum. ... The dorsal spinocerebellar tract conveys proprioceptive information from the body to the cerebellum. ... The accessory cuneate nucleus is located lateral to the cuneate nucleus in the medulla oblongata at the level of the sensory decussation (the crossing fibers of the posterior column/medial lemniscus tract). ...

Spinal cord segments

The human spinal cord is divided into 31 different segments, with motor nerve roots exiting in the ventral aspects and sensory nerve roots entering in the dorsal aspects. The ventral and dorsal roots later join to form paired spinal nerves, one on each side of the spinal cord. In zootomy, several terms are used to describe the location of organs and other structures in the body of bilateral animals. ... The word dorsal can refer to many different things. ... The term spinal nerve generally refers to the mixed spinal nerve, which is formed from the dorsal and ventral roots that come out of the spinal cord. ...

There are 31 spinal cord nerve segments in a human spinal cord:

• 8 cervical segments (nerves exit spinal column above C1 and below C1-C7)
• 12 thoracic segments (nerves exit spinal column below T1-T12)
• 5 lumbar segments (nerves exit spinal column below L1-L5)
• 5 sacral segments (nerves exit spinal column below S1-S5)
• 1 coccygeal segment (nerves exit spinal column at coccyx)

Because the vertebral column grows longer than the spinal cord, spinal cord segments become higher than the corresponding vertebra, especially in the lower spinal cord segments in adults. In a fetus, the vertebral levels originally correspond with the spinal cord segments. In the adult, the cord ends around the L1/L2 vertebral level at the conus medullaris, with all of the spinal cord segments located superiorly to this. For example, the segments for the lumbar and sacral regions are found between the vertebral levels of T9 and L2. The S4 spinal nerve roots arise from the cord around the upper lumbar/lower thoracic vertebral region, and descend downward in the vertebral canal. After they pass the end of the spinal cord, they are considered to be part of the cauda equina. The roots for S4 finally leave the vertebral canal in the sacrum. A diagram of a thoracic vertebra. ... The conus medullaris is the terminal end of the spinal cord. ... The cauda equina is a structure within the lower end of the spinal column, that consists of nerve roots and rootlets from above. ... For the record label, see Sacrum Torch. ...

There are two regions where the spinal cord enlarges:

• Cervical enlargement - corresponds roughly to the brachial plexus nerves, which innervate the upper limb. It includes spinal cord segments from about C4 to T1. The vertebral levels of the enlargement are roughly the same (C4 to T1).

• Lumbosacral enlargement - corresponds to the lumbosacral plexus nerves, which innervate the lower limb. It comprises the spinal cord segments from L2 to S3, and is found about the vertebral levels of T9 to T12.

The cervical enlargement corresponds with the attachments of the large nerves which supply the upper limbs. ... The brachial plexus is an arrangement of nerve fibres (a plexus) running from the spine (vertebrae C5-T1), through the neck, the axilla (armpit region), and into the arm. ... In humans, the upper limb is an anatomical term for the limb that is attached to the pectoral girdle. ... The lumbar enlargement (or lumbosacral enlargement) gives attachment to the nerves which supply the lower limbs. ... The anterior divisions of the lumbar nerve, sacral nerve, and coccygeal nerves form the lumbosacral plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic. ... In humans, the lower limb is an anatomical term for the limb that is attached to the pelvic girlde, what is commonly referred to as the leg. ...

Embryology

The spinal cord is made from part of the neural tube during development. As the neural tube begins to develop, the notochord begins to secrete a factor known as Sonic hedgehog or SHH. As a result, the floor plate then also begins to secrete SHH and this will induce the basal plate to develop motor neurons. Meanwhile, the overlying ectoderm secretes bone morphogenetic protein (BMP). This will induce the roof plate to begin to also secrete BMP which will induce the alar plate to develop sensory neurons. The alar plate and the basal plate are separated by the sulcus limitans. In the developing vertebrate nervous system, the neural tube is the precursor of the central nervous system, which comprises the brain and spinal cord. ... Sonic hedgehog homolog (SHH) is one of three proteins in the mammalian hedgehog family, the others being desert hedgehog (DHH) and Indian hedgehog (IHH). ... In the develping nervous system, the floor plate is a neural tube structure that separates the left and right components of the basal plate. ... In vertebrates, motoneurons (also called motor neurons) are efferent neurons that originate in the spinal cord and synapse with muscle fibers to facilitate muscle contraction and with muscle spindles to modify proprioceptive sensitivity. ... The ectoderm is outermost of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. ... Bone morphogenetic proteins (BMPs) are growth factors belonging to the TGF-β (Transforming Growth Factor-beta) super family with a strong ability to induce new bone and/or cartilage formation. ... The alar plate (or alar lamina) is a neural structure in the embryonic nervous system, part of the dorsal side of neural tube, that involves the communication of general somatic and general visceral sensory impulses. ... The alar plate (or alar lamina) is a neural structure in the embryonic nervous system, part of the dorsal side of neural tube, that involves the communication of general somatic and general visceral sensory impulses. ... In the fourth ventricle, the sulcus limitans forms the lateral boundary of the medial eminence. ...

Additionally, the floor plate will also secrete netrins. The netrins act as chemoattractants to decussation of pain and temperature sensory neurons in the alar plate across the anterior white commissure where they will then ascend towards the thalamus. Netrin is a class of protein involved in axon guidance, genetically conserved across C. elegans, Drosophila, frogs, and mice. ... Decussation is used in biological contexts to describe a crossing. ... The thalamus (from Greek θάλαμος = bedroom, chamber, IPA= /ˈθæləməs/) is a pair and symmetric part of the brain. ...

Lastly it is important to note that the past studies of Viktor Hamburger and Rita Levi-Montalcini in the chick embryo have have been further proven by more recent studies which demonstrated that the elimination of neuronal cells by programmed cell death (PCD) is necessary for the correct assembly of the nervous system.

Overall, spontaneous embryonic activity has been shown to play a role in neuron and muscle development, but is probably not involved in the initial formation of connections between spinal neurons.

Injury

Main article: Spinal cord injury

Spinal cord injuries can be caused by falling on the neck or back, or having the spinal cord moved or disrupted in another way. The vertebral bones or intervertebral disks can shatter, causing the spinal cord to be punctured by a sharp fragment of bone. Usually victims of spinal cord injuries will suffer loss of feeling in certain parts of their body. In milder cases a victim might only suffer loss of hand or foot function. More severe injury may result in paraplegia, tetraplegia, or full body paralysis below the site of injury to the spinal cord.

Spinal cord injury, or myelopathy, is a disturbance of the spinal cord that results in loss of sensation and/or mobility. ... Intervertebral discs lie in between adjacent vertebrae in the spine. ... Grays Anatomy illustration of a human femur. ... The hands (med. ... For other uses, see Foot (disambiguation). ... Paraplegia is a condition in which the lower part of a persons body is paralyzed and cannot willfully function. ... Quadriplegia is caused by damage to the spinal cord at a high level (e. ... This article does not cite any references or sources. ...

Damage to upper motor neurons axons in the spinal cord results in a characteristic pattern of ipsilateral deficits. These include hyperreflexia, hypertonia and muscle weakness. Lower motor neuronal damage results in its own characteristic pattern of deficits. Rather than an entire side of deficits, there is a pattern relating to the myotome affected by the damage. Additionally, lower motor neurons are characterized by muscle weakness, hypotonia, hyporeflexia and muscle atrophy. Hyperreflexia is defined as overactive or overresponsive reflexes. ... An increase in stiffness, tension, and spasticity of a muscle. ... In vertebrate embryonic development, a group of tissues formed from somites that develop into the body wall muscle. ... Hypotonia is a condition of abnormally low muscle tone (the amount of tension or resistance to movement in a muscle), often involving reduced muscle strength. ... Hyporeflexia is the opposite of hyperreflexia: the presence of below normal or absent reflexes. ... // Clinical settings of atrophy There are many diseases and conditions which cause a decrease in muscle mass, known as atrophy. ...

The two areas of the spinal cord most commonly injured are the cervical spine (C1-C7) and the lumbar spine (L1-L5). (The notation C1, C7, L1, L5 refer to the location of a specific vertebra in either the cervical, thoracic, or lumbar region of the spine.) A cervical vertebra Cervical vertebrae (Vertebrae cervicales) are the smallest of the true vertebrae, and can be readily distinguished from those of the thoracic or lumbar regions by the presence of a foramen (hole) in each transverse process. ... A typical lumbar vertebra The lumbar vertebrae are the largest segments of the movable part of the vertebral column, and can be distinguished by the absence of a foramen (hole) in the transverse process, and by the absence of facets on the sides of the body. ... A diagram of a thoracic vertebra. ...

Additional images

Diagrams of the spinal cord. Image File history File links Size of this preview: 211 × 599 pixel Image in higher resolution (264 × 750 pixel, file size: 13 KB, MIME type: image/png) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Spinal cord Wikipedia...

Cross-section through the spinal cord at the mid-thoracic level. Image File history File links No higher resolution available. ...

Cross-sections of the spinal cord at varying levels. Image File history File links No higher resolution available. ...

See also

Wikimedia Commons has media related to:

Spinal cord

• cauda equina
• conus medullaris
• meninges
• spinal nerves
• lumbar puncture

Image File history File links Commons-logo. ... The cauda equina is a structure within the lower end of the spinal column, that consists of nerve roots and rootlets from above. ... The conus medullaris is the terminal end of the spinal cord. ... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ... The term spinal nerve generally refers to the mixed spinal nerve, which is formed from the dorsal and ventral roots that come out of the spinal cord. ... A patient undergoes a lumbar puncture at the hands of a neurologist. ...

External links

• Spinal Cord Histology - A multitude of great Images from the University of Cincinnati
• Spinal Cord Injuries Australia (formerly Australian Quadriplegic Association AQA, established 1967) provides information about the disability and services for affected people, advocacy, accommodation, employment, peer support.
• Spinal Cord Medical Notes - Online medical notes on the Spinal Cord
• eMedicine: Spinal Cord, Topographical and Functional Anatomy
• WebMD. May 17, 2005. Spina Bifida - Topic Overview Information about Spina Bifida in fetuses and throughout adulthood. WebMD children's health. Retrieved March 19, 2007.