A crucial structure that links your brain to the rest of your body is the spinal cord.

It reaches down to your lower back from the lower part of your brain. The spinal cord transmits information to your brain and assists it in carrying out numerous essential functions, including limb movement.

What Is Spinal Cord?

The spinal cord is a long, tube-like structure extending from the base of your brain (the brain stem). It’s made of a collection of nerves and is encircled and protected by the bones of the spine (vertebrae).

Spinal Cord Anatomy

The spinal cord is a vital part of the central nervous system, along with your brain. It’s around 50 centimetres long, though the length may vary in different individuals. The spinal cord is divided into four regions:

• Cervical

• Thoracic

• Lumbar

• Sacral

It is covered by the meninges, which consists of three layers:

• Dura mater:

This is the tough, outermost layer tasked with protecting your spinal cord from injury.

• Arachnoid mater: 

This thin, transparent central layer gets its name from its spider-web-like appearance.

• Pia mater:

The innermost layer of connective tissue is called the pia mater. It directly connects to your spinal cord.

The spinal cord's cervical (neck) and lumbar (lower back) parts are significantly larger than the rest. The most minimal piece of the spinal rope is known as the "cauda equina," which in Latin means the "pony's tail." Because the nerve bundle in this region resembles a horse's tail, it was given this name.

Cerebrospinal fluid surrounds and suspends the spinal cord within the 33 vertebrae of the spinal column. From this cylinder, small nerves from the spinal cord branch out. They are referred to as roots, and they extend out of the vertebrae through small openings to connect various body parts.

Spinal Cord Nerves

A group of 31 nerves make up the spinal nerves. The dorsal sensory root and the ventral motor root are the two roots that connect these nerves to the spinal cord.

Sensory impulses are transmitted to the spinal cord by the sensory root fibres. The motor roots carry impulses from the spinal cord.

The spinal nerves carry messages to and from the skin of specific regions of the body called dermatomes.

The spinal cord nerves can be grouped as:

• Cervical

• Thoracic

• Sacral

• Lumbar

• Coccygeal

Cervical Nerves

Cervical means of the neck. There are 8 cervical nerves that emerge from the cervical spine (C1-C8).

Thoracic Nerves

Thoracic means of the chest. There are 12 thoracic nerves that emerge from the thoracic spine (T1-T12).

Lumbar Nerves

Lumbar means from the lower back region. There are 5 lumbar nerves that emerge from the lumbar spine (L1-L5).

Sacral Nerves

Sacral means of the sacrum. The sacrum is a bony plate at the base of the vertebral column.

There are 5 sacral nerves that emerge from the sacral bone (S1-S5).

Coccygeal Nerves

Coccygeal means the tailbone. There is 1 nerve that emerges from the coccygeal bone.

Spinal Cord Functions

The transmission of signals from the brain to various body parts is one of the spinal cord's primary functions. It does this through the nerves that connect your brain to other specific body parts. These nerve impulses serve three primary purposes. They:

• Control how your body moves: Through the nerves, your brain communicates with other body parts to perform normal movements like walking, standing, and running. It also regulates involuntary bodily functions like breathing, bowel and bladder movements, and your heartbeat.

• Transmits sensory information to the brain: The nerves also carry signals from different parts of your body to your brain. These include sensations like heat, pressure, and pain.

• Keep your reflexes in check. Some reflex actions are also controlled by the nerves in your spinal cord without your brain being involved.

Spinal Cord Conditions

Any disruption of spinal cord activity due to injury or disease could lead to serious conditions, including the loss of motor and sensory functions. In severe cases, this loss could be permanent.

• Spinal fractures

Spinal fractures can occur when the bones in the neck, spine, and back break. Trauma, accidents, or genetic conditions can cause fractures.

• Spinal deformities

These can result from spine conditions like scoliosis and kyphosis, which cause abnormal curvatures. Spinal fractures and other conditions like spondylolisthesis and ankylosing spondylitis can also cause these deformities.

• Ankylosing spondylitis

This is a form of arthritis that causes the spine's bones to become inflamed. Joints at the junction of your pelvis and spine may also experience inflammation from time to time. This condition affects men more frequently.

• Spondylosis

In cases of spondylosis, which can occur in the cervical region (also known as cervical spondylosis) or in the lumbar and thoracic regions (also known as thoracic spondylosis of lumbar spondylosis, respectively), the vertebrae and discs that are located between the spinal cord bones wear out.

• Spinal stenosis

The spine narrows due to injury or a disease such as osteoarthritis, putting undue pressure on the spinal cord and the nerves.

• Herniated discs

A herniated disc is a condition in which one of the gel-like discs that separate the vertebrae breaks and presses on a nearby nerve. This could result in additional conditions like back pain and sciatica.

• Degenerative disc disease

Also known as osteoarthritis of the spine, this is a condition where the discs between the vertebrae become dry and wear out. This typically occurs in old age, but impact injuries can also be the cause.

• Spinal tumours

When there’s an unusual tissue collection in and around the spinal cord or the spinal column, it may become a tumour. Malignant (cancerous) tumours are more harmful and can occur when tumours from other parts of the body spread to the spine.

Spinal Cord Injuries

Any damage to the spinal cord or spinal nerves affects the normal functioning of the spinal cord and is permanent and lasts a lifetime without replacement.

It frequently alters the body's strength, posture, and reflexes over time. After an injury, the extent and location of voluntary control of limbs vary.

When a person loses the ability to move or sense below the injury, that is a complete injury. The injured person is able to perform some sensory and motor functions due to the incomplete injury.

Other muscles and vital organs are also affected by spinal cord injury, in addition to the spinal nerves and the vertebral column.

Paralysis from an injury can be of two types:

• Tetraplegic

• Paraplegic

Tetraplegia is a paralysis that results in total or partial loss of use of all four limbs and torso.

Paraplegia, on the other hand, is similar to tetraplegia, except it doesn’t affect the arms.

These injuries cause intense shooting pain due to damaged nerve fibers, loss of sensation, delayed or exaggerated reflexes, changes in sexual functions, and inability to move limbs voluntarily. Additionally, it causes muscle spasms, cough, and shortness of breath.