The spine is a critical part of the body, relaying impulses, sensations such as touch and pain, and information that controls and regulates muscles and organs. Proper spinal alignment supports a healthy nervous system.
Practicing core-strengthening exercises, good posture and proper lifting techniques can all help keep your spine healthy.
The Spinal Cord
The spinal cord is the main pathway for communication between your brain and the rest of your body. It extends down from the medulla oblongata, a part of your brain that contains your nerve cells. It is a long, tube-like structure that runs through the vertebrae of your spine (spinal column) and carries signals from one part of your body to another. In addition, the spinal cord helps to control muscle movement and to sense things like touch, pressure and pain.
The spine is a stack of 33 bones called vertebrae, five of which are fused to form the sacrum and four to form the coccyx (tailbone). The spinal cord lies inside of the protective sac of cerebrospinal fluid that surrounds it, and it is shielded by three layers of bone-like tissue called the dura mater, arachnoid mater and pia mater.
Your spinal cord is divided into sections, each of which sends messages in different directions and may correcting spinal misalignment that may interfere with nerve function. For example, in the cross-section of your spinal cord, you can see that the gray matter “butterfly” areas are divided into two “wings.” The top wings reach toward your spine’s vertebrae, and the bottom wings are directed toward your internal organs. Each wing of the gray matter is also coated in a thick fatty substance called myelin, which speeds up the transmission of nerve impulses.
When a signal is sent to the spinal cord, it travels down through one of thirty-one pairs of nerve roots that leave each of your vertebrae on either side through spaces in the spine called neural foramina. Each of the nerve pairs spreads throughout your body to deliver commands from the brain and spinal cord to the rest of your body’s muscles and tissues.
The spinal cord also receives sensory information from the rest of your body through afferent nerve fibers, which carry signals about things like pain, temperature and position to the brain. These sensory signals are processed in the spinal cord and filtered by a group of support cells called astrocytes. Astrocytes help to protect neurons by making and secreting proteins that counteract substances that might damage them, such as glutamate, which if it builds up in excess can cause neurons to become overexcited and die.
The Nervous System
Your spinal cord is a tube of nerve tissue that runs through the centre of your spine and is protected by the bones of the back (vertebrae). From there, nerves branch out into your arms, legs and torso. Nerves connecting to the brain are part of your central nervous system; those elsewhere in the body are part of the peripheral nervous system.
The nervous system helps all parts of the body communicate with each other and react to changes both inside and outside the body. It also controls your body’s automatic functions, like breathing or regulating glands without you needing to think about them. It can help you walk, see, read and remember, as well as feel emotions.
Every organ, muscle and gland in the body is connected to your nervous system by nerve fibres. This is why the spine is so important – it connects and protects the brain and spinal cord, which are so vital to the overall function of your body.
Nerve cells (neurones) are the main building blocks of your nervous system. Each neuron has a cell body with a nucleus and cytoplasm, dendrites that carry electrical impulses to the cell, and a long axon that carries the impulses away from the cell. Neurons communicate with each other by exchanging information through a gap between the axon of one neuron and the dendrites of the next neuron, called a synapse.
Neurons can increase or decrease their connections with other nerve cells. This process may explain how memories are formed. Nerve cells can also die, resulting in conditions such as epilepsy or multiple sclerosis. They can also be damaged by infections or blocked blood flow, causing encephalitis and meningitis respectively.
The peripheral nervous system includes sensory nerves that relay information from your eyes, ears and skin to the central nervous system; and motor nerves that obey commands from the CNS and make your muscles contract or relax, allowing you to move. It can also control the functions of your internal organs and is divided into two subsystems, the autonomic and enteric nervous systems.
The Spine’s Function
The spine supports your head and shoulders, protects the spinal cord and gives you balance, stability and movement. It also provides a flexible channel for neurological signals that control basic body functions such as breathing, digestion and heart rate. It’s like the central highway for neural traffic. Any blockages or detours will impact how the messages get from the brain to the rest of the body.
The spinal cord runs through a protective canal of bone (called the vertebral column) formed by 24 back bones called vertebrae. These bones are stacked on top of each other and held together by ligaments and muscles. The spinal cord is encased in the vertebrae and protected by a layer of cerebrospinal fluid that acts as a cushion against shock or injury.
Between each pair of vertebrae are stout, cylindrical discs that help absorb pressure and shock. The outer portion of each disc is composed of a tough fibrous shell called the annulus fibrosus. Inside is a gel-like substance that cushions the spine and allows for limited flexibility. The intervertebral discs are held in place by pairs of joints, called facet joints, that connect each vertebra to the vertebra above and below. Each joint is similar to a knee or elbow joint in that they are synovial and move with the spine as you bend, twist and move your back.
A healthy spine is supported by strong bones and muscles, flexible ligaments and tendons and sensitive nerves. The natural curves of the neck (cervical), thoracic and lumbar spine work together like a coiled spring to absorb shock, maintain balance and support movement. An abnormal curve from front-to-back is called a swayback or kyphosis, and an abnormal curve from side-to-side is called scoliosis.
The spine’s primary function is to provide structure and protection for the nervous system. Without a healthy spine, it can be difficult to walk, sit upright and lift heavy objects. It can even affect your mood and overall health. For example, a spine that’s not properly aligned in the thoracic region can interfere with normal nerve function related to your stomach and intestines, leading to digestive problems.
The Spine’s Symptoms
When spinal nerves are pinched or compressed, they stop working as well. This can cause pain, weakness and other symptoms throughout the body that affect how you move, feel and function. The cause can be traumatic or nontraumatic (such as from a car accident). It can also be caused by age-related conditions and diseases. For example, a herniated disk may be the result of one or more vertebrae becoming misaligned and pressing on the spinal cord. Other causes include spinal fractures, spinal stenosis (narrowing of the spinal canal) and tumors that grow on or near your spine. Some diseases, like multiple sclerosis and transverse myelitis, are when your immune system mistakenly attacks part or all of your spinal cord.
The spinal cord has two paths that carry messages back and forth between your brain and the rest of your body: motor tracts and sensory tracts. The latter carry information about pain, temperature, pressure and the position of your limbs to your brain. The spinal cord also relays information to your brain from the skin, muscles and internal organs, indicating that your body is moving or hurting.
Whether the injury is traumatic or nontraumatic, spinal cord damage can affect all the functions controlled by that section of the cord. A neck injury can cause symptoms that include changes to how you use your arms, hands and fingers, and can make it difficult to button your shirt or zipper your jacket.
Injuries to your spine can be diagnosed by X-rays, CT scans and magnetic resonance imaging (MRI), which use a strong magnet and radio waves to produce computer-generated images of bones and soft structures, such as discs. MRI can give doctors the most accurate picture of the spinal cord and surrounding structures, such as blood vessels and ligaments.
Pain that radiates into your arms, legs and around the chest from your back toward the front of your abdomen indicates that there is structural pinching of nerves in your spine and needs to be considered for surgical consideration. This usually implies a more severe condition that may require surgery than nonsurgical care, which is often successful in alleviating the symptoms.
