Spinal Cord Anatomy
Before you can understand a spinal cord injury, you should first learn about the anatomy—the structures and function—of the spinal cord and the spinal column including the cervical spine, thoracic spine and lumbar spine.
Spinal Cord Injury
- The spinal column—also known as the backbone—provides support for the body and protects the spinal cord. The spinal column includes vertebrae, intervertebral discs, muscles, tendons, and ligaments. The spinal column is divided into three sections—cervical, thoracic, and lumbar. Each section is named and each vertebra is numbered. There are seven cervical (C1-C7), twelve thoracic (T1-T12), five lumbar vertebrae (L1-L5), and one sacral (S1) vertebra.
- The nervous system includes the brain, spinal cord, and spinal nerves. The brain is the master control for all body functions. The spinal cord serves as the main line of communication between the brain and the body. The spinal nerves relay messages to and from the spinal cord and other parts of the body.
- There are three types of messages that travel along the spinal cord. They are sensory, motor, and reflex.
- Injury to the spinal cord results in loss of feeling and movement below the injured area. A complete injury means that there is total loss of feeling and movement below the injury. With an incomplete injury some feeling and/or movement will stay below the level of injury.
- Quadriplegia is an injury in which both the arms and legs are affected. Paraplegia is loss of function in the legs.
- There are many causes of spinal cord injury. The most common causes are accidents like automobile, diving, and falls. Other problems that cause spinal cord injury are Guillain Barre, Transverse Myelitis, tumors, and Spina Bifida.
- Spinal shock occurs immediately after a spinal cord injury. The result is a loss of reflexes, movement and feeling below the level of injury. The return of reflex activity signals the end of spinal shock..
- The reflex function of the spinal cord may remain after spinal cord injury. Depending on the level of injury, reflexes can be used for bowel and bladder emptying and for reproductive functioning.
- Surgery may be needed to stabilize the spinal column and to prevent further injury to the spinal cord. For cervical injuries a wiring and fusion may be done. A halo device may be used to stabilize some types of cervical injuries. The halo is worn for 8 to 12 weeks while healing of the injured area takes place and allows the patient to be mobile. Harrington rods may be inserted for thoracic and lumbar injuries.
Spinal Cord Anatomy
To better understand a spinal cord injury,
What you should find about your spinal cord injury
- What is the level of your spinal cord injury?
- Do you have a complete or incomplete injury?
- Are you a quadriplegic or paraplegic?
- Do you have reflexes below your injury?
- Did you have surgery to your spinal column? If so, what type of surgery did you have?
Chart Showing Function After Spinal Cord Injury
|Spinal Cord Level/Spinal Nerve||Spinal Nerve Connected to Muscle||What Can the Muscles Do?|
|C3 to C4||1. Neck (sternocleid-mastoid)2. Shoulder (trapezius)|
|1. Fair Neck Control2. Shrug Shoulders|
|C5||Has above function plus:1. Shoulder (deltoid)|
2. Arm (biceps)
|1. Good neck control2. Fair to good shoulder control|
3. Arm bends at elbow
4. Forearm rotates up
|C6||Has above function plus:1. Wrist|
2. Forearm (all)
3. Some chest
|1. Good shoulder control2. Bend wrist up|
3. Turn hand down
4. Weak trunk
|C7||Has above function plus:1. All arm (triceps)|
2. More chest
3. Some finger
|1. Good arm control2. Some hand function|
3. Better chest function
|C8 – T4||Has above function plus:1. Hand|
2. Some chest
3. All arm
4. Some trunk/back
|1. T1: all arm and hand2. Better trunk control|
|T5 – T12||Has above function plus:1. All chest|
2. All breathing (intercostal)
|1. All upper body2. Fair to good trunk control|
|L1 – L5||Has above function plus:1. All lower back|
2. Some leg (quadriceps)
|1. Bend hips2. Straighten knees|
|S1 – S5||Has above function plus:1. All knee|
2. All ankle
|1. Straighten hip2. Bend knee|
3. Good ankle control
4. Point toe
Complete and Incomplete Spinal Cord Injury
- A complete spinal cord injury means there is a total blockage of signals at the point of injury. There will not be any feeling or movement below the level of injury. A complete spinal cord can change the control of all the functions of the nervous system.
- An incomplete spinal cord injury means that there is partial damage to the spinal cord. Some feeling and movement lost will depend on how much damage is done to the spinal cord. The way that the bowel and bladder empties often changes too.
- Today, as far as we know, injury to the spinal cord is permanent. Whether or not your spinal cord injury is complete or incomplete is not always known right after a spinal cord injury.
The Reflex Function
- After spinal cord injury, reflexes will remain intact above the level of injury. If the spinal cord injury is above T12 some reflexes will probably be present below the level of injury. If the spinal cord injury is below L1 you probably will not have reflexes below the injured level. It is important to know if you have reflexes below your level of
injury so you will know how to care for your bowel and bladder.
- Immediately following a spinal cord injury the spinal cord goes into spinal shock. Spinal shock is a period of time when reflexes, movement, and feeling may be absent below the level of injury.
- Spinal shock may take hours, days, weeks, or months to resolve. The return of reflex activity below the level of injury is a sign that the person is coming out of spinal shock. The reason for spinal shock is not known.
Surgery to the Spinal Column
Surgery is most commonly done to stabilize the spinal column and to prevent more spinal cord damage. Damage may continue to occur if pressure remains on the cord. The type of surgery needed will depend on the type and level of injury.
Wiring And Fusion
- It is most often done on cervical injuries.
- The surgery may be done from the front or back of the neck depending on the type of injury.
- Surgery is done to the back of the neck most often.
- The bones (vertebrae) are put back into place if needed.
- The neck is positioned correctly, bone chips are removed from the hip and placed in the damaged area.
- The broken bones are wired together with the bone chips from the hip.
- A Philadelphia (hard) collar is worn for 6 to 8 weeks after surgery to add support to the repaired area until healing takes place.
- After 6 to 8 weeks x-rays are taken to make sure the bone chips have fused with the broken bones making a strong supportive backbone.
- A Halo device may be used when there is a cervical injury.
- The halo ring is attached to the bones of the head.
- The ring is then attached to a halo vest with bars, to keep the head and neck in one position while the injured area is healing.
- The halo is worn for 8 to 12 weeks.
- X-rays are taken to make sure the bones have healed together.
- Harrington rods stabilize the thoracic and lumbar areas of the spinal column.
- The rods are about 6 inches long and are made of stainless steel.
- During surgery, the rods are placed behind and on both sides of the spinal column.
- After surgery these patients will follow a limited program to avoid certain activities like pulling, twisting, and pushing up until healing has taken place. They will also wear a Jewett brace to keep from bending and twisting.
- The limited program lasts 6 to 8 weeks.
- X-rays are taken to make sure the bones are healing and the rods are in position.
Glossary for Spinal Cord Injury
- The middle front part of the body (stomach area)
- Cauda Equina
- A bundle of nerves which branch off the end of the spinal cord and carry messages about bowel, bladder, and reproductive function. It is located below the lumbar area of the spinal cord and looks like a horse’s tail.
- The neck area, where 8 cervical nerves carry messages for movement and feeling to the arms, the hands, the fingers and the diaphragm.
- The main muscle of breathing located under the rib cage.
- Guillan Barre Syndrome
- A rare illness that affects the spinal nerves as well as the cranial nerves which renders the nerves unable to carry messages for movement, feeling, reflexes, bowel and bladder control.
- Harrington Rods
- Stainless steel rods placed on the back part of the spinal column during surgery to stabilize thoracic and lumbar injuries.
- Limited Program
- Patients with Harrington Rods are placed on a “limited program” during which the person is not allowed to do certain activities that may put pressure on the rods, until healing has taken place.
- Lower area of the back. The 5 lumbar nerves carry messages for movement and feeling to the legs and hips.
- Motor Nerve
- A nerve which carries movement messages.
- Connects the brain and spinal cord with parts of the body; carries messages for movement and feeling.
- Nervous System
- Includes the brain, spinal cord, and nerves. It controls almost all body functions.
- Loss of movement and feeling.
- Paraplegia occurs when there is injury to the spinal cord in the thoracic, lumbar, or sacral area. This causes loss of feeling and movement in the chest, stomach area and legs.
- Quadriplegia occurs when there is injury to the spinal cord in the cervical area. This causes loss of feeling and movement in the arms, chest, stomach area and legs.
- Movement of a muscle caused by a signal (pain, heat, pressure), that does not come from the brain. It goes from the muscle to the spinal cord and then back to the muscle.
- Sacral (tailbone)
- The lowest part of the back, includes five nerves which carry messages for movement and feeling to the legs, feet, bowel, bladder, and reproductive organs.
- Sensory Nerve
- A nerve which carries feeling (touch, pressure, pain, temperature) messages.
- An uncontrolled muscle movement.
- Spinal Column
- The backbone, made up of many sections of bone (vertebrae) stacked one on top of the other. The spinal cord runs down through a canal in the middle of this column.
- Spinal Cord
- Carries messages about movement and feeling to and from the Brain; contains reflex centers.
- Spinal Fluid
- Fluid which flows around the brain and spinal cord protecting them from the injury.
- Spinal Shock
- A period of time when reflexes, movement and feeling are absent below the level of injury.
- Paralysis affecting the arms, chest, stomach area and legs.
- The upper and mid back area, where twelve nerves carry messages for movement and feeling to the mid body.
- Bones which make up the backbone.