spinal cord

Examples of spinal cord in the following topics:

• Spinal Cord

  • A cross-section of the spinal cord looks like a white oval containing a gray butterfly-shape .
  • The spinal cord also controls motor reflexes.
  • In the United States, there around 10,000 spinal cord injuries each year.
  • Because the spinal cord is the information superhighway connecting the brain with the body, damage to the spinal cord can lead to paralysis.
  • The extent of the paralysis depends on the location of the injury along the spinal cord and whether the spinal cord was completely severed.

• Overview of the Spinal Cord

  • A lumbar puncture (spinal tap) is an example of a medical procedure that directly targets the spinal cord.
  • The brain and spinal cord together make up the central nervous system (CNS).
  • The spinal cord is divided into cervical, thoracic, and lumbar regions.
  • The nerves of the lumbosacral spinal cord supply the pelvic region, legs, and feet.
  • Thirty-one pairs of spinal nerves (sensory and motor) branch from the human spinal cord.

• Spinal Cord Trauma

  • A spinal cord injury (SCI) refers to any injury to the spinal cord that is caused by trauma and not disease.
  • A spinal cord injury (SCI) refers to any injury to the spinal cord that is caused by trauma instead of disease.
  • The American Spinal Injury Association (ASIA) first published an international classification of spinal cord injury in 1982, called the International Standards for Neurological and Functional Classification of Spinal Cord Injury.
  • An incomplete spinal cord injury involves preservation of motor or sensory function below the level of injury in the spinal cord.
  • Autonomic dysreflexia (AD) occurs most often in spinal cord-injured individuals with spinal lesions above the T6 spinal cord level, although, it has been known to occur in patients with a lesion as low as T10.

• Spinal Cord Compression

  • Spinal cord compression occurs when the spinal cord is compressed by bone fragments.
  • Spinal cord compression develops when the spinal cord is compressed by bone fragments from a vertebral fracture, a tumor, abscess, ruptured intervertebral disc, or other lesion .
  • It is regarded as a medical emergency independent of its cause, and requires swift diagnosis and treatment to prevent long-term disability due to irreversible spinal cord injury.
  • The median survival of patients with metastatic spinal cord compression is about 12 weeks, reflecting the generally advanced nature of the underlying malignant disease.
  • In spinal cord compression, the spinal cord (shown here) may be compressed by bone fragments from a vertebral fracture, a tumor, abscess, ruptured intervertebral disc, or other lesion.

• Spina Bifida

  • Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open.
  • The protruded portion of the spinal cord and the nerves that originate at that level of the cord are damaged or not properly developed .
  • As a result, there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect.
  • The spinal cord lesion or the scarring due to surgery may result in a tethered spinal cord.
  • In some individuals, this causes significant traction and stress on the spinal cord.

• The Central Nervous System (CNS)

  • The CNS includes the brain and spinal cord, which together comprise the body's main control center.
  • The CNS is comprised of the brain, brain stem, and spinal cord.
  • The spinal cord connects the brain and brain stem to all of the major nerves in the body.
  • Spinal nerves originate from the spinal cord and control the functions of the rest of the body.
  • This data is then sent back through the spinal cord to muscles and glands for motor output.

• Spinal Cord Grey Matter and Spinal Roots

  • The length of the spinal cord is much shorter than the length of the bony spinal column.
  • The spinal cord is compressed dorsoventrally, giving it an elliptical shape .
  • Each segment of the spinal cord is associated with a pair of ganglia, called dorsal root ganglia, which are situated just outside of the spinal cord.
  • Hence, the spinal ganglia can be regarded as grey matter of the spinal cord that became translocated to the periphery.
  • Describe the grey matter and spinal roots of the spinal cord

• Subdivisions of the Nervous System

  • The CNS includes the brain and spinal cord, while the PNS is a network of nerves linking the body to the brain and spinal cord.
  • White matter includes all of the nerves of the PNS and much of the interior of the brain and spinal cord.
  • The PNS is a vast network of nerves consisting of bundles of axons that link the body to the brain and the spinal cord.
  • The central nervous system (2) is a combination of the brain (1) and the spinal cord (3).
  • The brain and the spinal cord are the central nervous system (CNS) (shown in yellow).

• Sensory-Somatic Nervous System

  • Spinal nerves transmit sensory and motor information between the spinal cord and the rest of the body.
  • Each sensory neuron has one projection with a sensory receptor ending in skin, muscle, or sensory organs, and another that synapses with a neuron in the dorsal spinal cord.
  • Motor neurons have cell bodies in the ventral gray matter of the spinal cord that project to muscle through the ventral root.
  • These neurons are usually stimulated by interneurons within the spinal cord, but are sometimes directly stimulated by sensory neurons.
  • The cell bodies of motor neurons are found in the ventral portion of the gray matter of the spinal cord.

• Brachial Plexus

  • The brachial plexus is formed by the four lower cervical spinal nerves and the first thoracic spinal nerve.
  • The brachial plexus is divided into roots, trunks, divisions, cords, and branches.
  • Five roots: The five anterior rami of the spinal nerves, after they have given off their segmental supply to the muscles of the neck.
  • These six divisions will regroup to become the three cords.
  • The cords are named by their position with respect to the axillary artery: