Anatomy of the Spinal Cord

The spinal cord is part of the central nervous system, which helps control the sense of feeling, movement, and functioning of the body's internal organs. Made up of bundles of nerves, the spinal cord carries signals from your body to your brain, and vice versa. 

The spinal cord is tube-shaped and extends from the brain all the way down to the lumbar, or lower, region of the spine. Branching off from the spinal cord are small nerves, sometimes called nerve roots. These roots emerge from small spaces between the vertebrae, the bones that surround the spinal cord, and run to various parts of the body.

The entire spinal cord is surrounded by a liquid called cerebrospinal fluid; the fluid protects the spinal cord from injury. The spinal cord is also protected by three layers of coverings called the meninges—the dura mater, the arachnoid mater, and the pia mater.

The spinal cord and spine are divided into four regions. Damage to the nerves in the spinal cord can result in various medical conditions, depending on the region that is affected.

Anatomy of the spinal cord
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Cervical region

This portion of the spinal cord contains nerve roots that connect to the upper body, arms, and hands. Between the vertebrae in the spine are spongy cushions called intervertebral disks. If the disks collapse, they may "pinch" the nerves in the cervical spine, leading to a condition called cervical radiculopathy. This condition can cause pain or numbness in the arms. If the cervical region of the spinal cord is severely injured, as from a fall, it can cause quadriplegia, a condition in which most of the body is paralyzed.

Thoracic region

The nerve roots in the thoracic spine run to the chest and abdomen and control movement in those portions of the body. When the brachial plexus, a network of nerves in this area, becomes compressed, it can lead to a condition known as thoracic outlet syndrome, causing numbness or pain in the neck, shoulder, and armpit. Serious injuries to the thoracic region of the spinal cord can lead to paraplegia, a paralyzation of the lower portion of the body.

Lumbar region

The lumbar spine is the lower region of the back. Nerve roots coming from the spinal cord in the lumbar spine control the legs, bladder, and bowel. The lumbar region is where the spinal cord ends. It continues as a bundle of nerve roots in the lower back, known as the cauda equina. If an intervertebral disk in the lumbar spine herniates or moves into the space containing a nerve root, lower back pain can result. In severe cases, it can cause cauda equina syndrome, a serious condition that compresses the nerve roots and results in loss of sensation and movement.

Sacral region

The lowest part of the spine contains five pairs of nerves, which control the thighs, lower legs, and the genital and anal areas. Sacral nerve injury can happen when the bones in the sacral region become fractured. This can lead to lower back pain, urinary incontinence, loss of feeling in the foot, and even sexual dysfunction. 

Maintaining a healthy spinal cord

Although some spinal cord injuries, such as those from car accidents, can't always be avoided, you can take many steps to preserve the health of your spine and the spinal cord nerves within it. Maintaining or attaining a healthy weight is suggested because excess pounds can put unnecessary stress on your back. To strengthen the bones of your spine, a calcium-rich diet is also essential. Finally, know your limits and avoid picking up items that are too heavy for you to lift safely.