The spinal cord is a long bundle of nerves and cells that runs from the bottom of the brain to the lower back. It is responsible for transmitting information from the brain to the rest of the body.
The anatomy and functions of the spinal cord are discussed on this page.
It also contains information about spinal cord injuries.
Anatomy
The length of the spinal cord varies from person to person. According to some estimates, females have a spinal chord that measures approximately 43 centimeters (cm), whereas boys have a spinal chord that measures around 45 centimeters (cm).
The spinal cord is made up of three sections: cervical (neck), thoracic (chest), and lumbar (lower back).
Three layers of tissue protect the spinal cord: the dura mater, arachnoid mater, and pia mater. Physicians refer to these layers as "meninges." The layers are as follows:
- The outermost layer of the meninges that surround the spinal cord is known as the dura mater. It's a protective, rigid layer. The epidural space is located between the dura and the arachnoid space. Local anesthetics, such as those used to treat a lung or abdominal aneurysm, may be administered here to alleviate pain during birth and some surgical procedures.
- The arachnoid mater is the protective coating of the spinal cord's middle layer. The subarachnoid space is located between the arachnoid mater and the pia mater. The cerebrospinal fluid (CSF) is kept in this compartment. A sample of CSF may be taken by a clinician to screen for infection, such as meningitis. They can also inject local anesthetic into this area for various surgical procedures, such as a cesarean delivery or a knee replacement.
- The pia mater is a layer that immediately covers the spinal cord. The spinal cord and its protective coverings are protected by the vertebral column, or spinal bones. These bones extend from the base of the skull to the sacrum, a bone that inserts into the pelvic cavity. The cervical, thoracic, and lumbar spines each have a different number of bones. There are seven bones in the cervical column, twelve in the thoracic column, and five in the lumbar column.
The cross-section of the spinal cord
If you cut the spinal cord horizontally, you'll see a protective layer-coated circular section in the middle (the meninges). This circular area is surrounded by nerve projections. These are nerves that go from the spinal cord to various regions of the body and produce sensation.
A cross-section of the spinal cord reveals the following main regions:
- The gray matter of the spinal cord is made up of nerve cell bodies and is dark and butterfly-shaped.
- The white matter of the spinal cord surrounds the gray matter and contains myelin-coated cells that help nerves communicate more quickly. On nerve cells in the gray matter, myelin is not as densely wrapped.
- The posterior root is the portion of the nerve that branches off the back of the spinal column. In a cross-section of the spinal cord, the higher wings of the gray matter "butterfly" reach toward the spinal bones. The lower wings reach the front of the body and its interior organs.
- The front root of a nerve is the part of the nerve that branches off the front of the spinal column.
- The spinal ganglion is made up of nerve bodies, including sensory neurons.
- The posterior and anterior roots come together to produce a spinal nerve. In the spine, there are 31 pairs of nerves. Both sensation and movement in the body are controlled by them.
- The backbone's spinal cord does not run the entire length of it. The upper lumbar spine is where it commonly grinds to a standstill.
In adults, this is usually the first or second lumbar vertebrae. At the second or third lumbar vertebrae, children's spinal cords may come to a standstill.
Functions
The spinal cord is involved in several aspects of bodily function. Some examples of key functions are as follows:
- Receiving brain signals: The spinal cord receives brain signals that control movement and autonomic functions.
- The spinal cord nerves also transmit information from the body to the brain, such as touch, pressure, and pain sensations.
- Motor reflexes may be controlled by the spinal cord independently of the brain. When a person's knee is touched in a certain place, the patellar reflex causes it to jerk involuntarily. Nerve impulses for movement, sensation, pressure, temperature, pain, and other activities are sent through the spinal cord.
Injuries
One of the most delicate sections of the human body is the spinal cord. As a result, it is at risk of being harmed. Spinal cord injuries can be caused by a variety of things, including car accidents, gunshot wounds, and sports-related injuries.
Because of the role the spinal cord plays in transmitting movement and sensation, damage to any part of it can cause long-term changes in a person's functioning.
Following an injury, healthcare providers may not always be aware of the extent to which a person's function would be lost.
The two most prevalent types of spinal cord injuries are full and incomplete.
A whole spinal cord injury causes the complete loss of sensation and motor function below the level of the damage.
According to the American Academy of Neurological Surgeons (AANS), about half of all spinal cord injuries are complete. The spinal cord does not have to be physically severed for a complete injury to occur; nonetheless, the damage may be severe enough that blood cannot flow to the nerve tissue, causing it to die.
When a person suffers from an incomplete spinal cord injury, he or she retains some function at or below the site of lesion. They could still be able to move or feel one side of their body.
The American Association of Neurological Surgeons (AANS) estimates that around 250,000–450,000 people in the United States have had a spinal injury.
Surgical methods and the passage of time can assist to lessen the effects of a spinal cord injury in some cases. Doctors routinely employ imaging scans and nerve function tests to determine the degree of a person's spinal cord damage.
Summary
The spinal cord is a complex network of nerve cells that regulates movement and sensation. It is responsible for transmitting information from the brain to the rest of the body.
Knowing where the protective spinal cord coverings are and how they operate might help healthcare practitioners provide pain management during certain procedures.
Spinal cord injuries can result in sensory loss, partial or complete paralysis, and even death. When playing sports or participating in other activities, one should always wear protective equipment to reduce the risk of harm.
However, avoiding an accident like this may not always be possible.