Spinal Cord and Nerves

Spinal Cord and Nerves

The spinal cord is a slender tubular-shaped structure about the diameter of the little finger.  It begins at the base of the brain; at the brain stem and extends downward and ends at the first lumbar (low back) vertebrae (abbreviated L1).  The end of the spinal cord is called the conus medullaris.  Thereafter, the cord splits into a bundle of nerves known as the cauda equina.  The cauda equina resembles a horse’s tail.

 

Protection

The structural design of the spine’s bony parts, such as the vertebral bodies and laminae create a hollow tube.  Inside the tube, the spinal cord is bathed and surrounded by cerebrospinal fluid; a colorless clear body fluid.  Three membranes (meninges) encase the spinal cord and provide additional protection.

Nerve Roots

Nerve roots branch off the spinal cord and exit the spinal canal through neuroforamen.  Neuroforamen are nerve passageways naturally created by intervertebral disc height between two vertebral bodies.  These passageways are at the left and right sides of the disc.  A nerve root is seen in the illustration below.

Purpose

The brain and the spinal cord make up the central nervous system (CNS).  Nerve roots branch outward through neuroforamen into the body forming the peripheral nervous system (PNS).  Nerve rootsinnervate, stimulate sensation (feeling) and function (movement).

  • Brain Stem:  It connects the brain and spinal cord.
  • Spinal Cord: Carries nerve impulses to and from the brain.

Nerve Roots

Region Number Area Innervated
Cervical 8 pair Head, neck, shoulders, arms, hands
Thoracic 12 pair Upper abdomen, check and back muscles
Lumbar 5 pair Lower back and legs
Sacral 5 pair Buttocks, legs, feet, and anal and genital areas

Dermatomes

Sometimes a spinal condition causes a specific area of the skin’s surface to feel pain, numbness, or tingling sensations.  The skin sensation originates from a single spinal nerve root.  Another name for the area of skin sensation is dermatome.

Rehabilitation Medicine Center of New York can help you resolve back and/or neck pain.  Our doctors precisely diagnose the cause of pain and welcome the opportunity to recommend non-surgical and surgical treatments to help you manage your condition.