What is 
Spinal Cord Injury ?

 Anatomy

The human spinal cord is a crucial part of the human body. The spinal cord and brain together make up the central nervous system. The main function of the spinal cord is to provide a link between the brain and the peripheral nervous system. The spinal cord also possesses neural circuitry which is directly used in reflexes. The spinal cord in comprised of nervous and supporting tissue.

            The spinal cord extends from the lower brain stem (the medulla oblongata), to the second lumbar vertebrae in the lower back. It is surrounded by a hollow bone vertebral column, which serves to protect the soft tissue of the spinal cord. This vertebral column is split into segments which are each connected by spinal discs. Each of the vertebral segments may bend slightly about each disc, allowing the entire back to bend at increased angles.

The spine consists of 5 regions and 33 segments

1. Cervical Vertebrae: There are 7 cervical vertebrae in the neck region

2. Thoracic Vertebrae: There are 12 thoracic vertebrae in the upper back region

3. Lumbar Vertebrae: There are 5 lumbar vertebrae in the lower back region

4. Sacral Vertebrae: The 5 sacral vertebrae are fused together to form the sacrum

5. Coccygeal Vertebrae: The 4 small coccygeal vertebrae are fused together to form the coccyx or tailbone


Spinal Cord Injury

Spinal cord injuries are the result of trauma to the spinal column. The vertebral column can compress or shatter, resulting in decreases in function. Spinal cord injuries are classified into two broad categories. Complete spinal cord injuries are the complete severing of the spinal cord in a trauma. No messages may pass through the injured site. Incomplete spinal cord injuries result in the spinal cord not being completely severed. Some nerve messages have the ability to pass through the injured site. Nerves in the human spinal cord do not have the ability to regenerate and full repair after being injured.

    Treatment for spinal cord injury often includes surgery, rest, and a regimen of rehabilitation. Corticosteroids, such as dexamethasone or methylprednisolone, are used to reduce swelling that may damage the spinal cord after a traumatic injury. 

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The spinal cord within the vertebral column contains millions of nerves.  The spinal cord itself is composed of 31 different segments. At every single segment, a nerves branch out to either side in very orderly fashion. These branches include both motor and sensory nerves that decrease in thickness as they travel away from the spinal cord. Each of the branches from the spinal cord send and receive signals for certain parts of the body.

Symptoms of a spinal cord injury vary somewhat depending on the location of the injury. Spinal cord injury causes weakness and sensory loss at and below the point of the injury. The diagram above shows the extent of paralysis when the spinal cord is injured at each level.