Spinal Cord Anatomy

Spinal Structure

The spinal cord is the main pathway that sends signals from your brain (specifically the medulla) to the various parts of your body. The cord itself is, essentially, a cable of nervous tissue and spinal cord fluid. Henry Gray's Anatomy of the Human Body states that the purpose of the spine is to "control and regulate all body functions."

This is a delicate system, which controls much of the movement and sensation throughout the body. For this reason, it is protected by 31 segments called vertebrae. The vertebrae allow the body additional mobility and flexibility, while providing much needed protection for the spinal cord.

The spinal cord is 45 centimeters long in men and 42 centimeters for women. This length is actually shorter than the spinal column itself, stopping at the last ridge of the thoracic vertebrae.

Every vertebra is named after its location on the spinal column. From top to bottom this includes 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. These sections have very specific functions, which are explained below. At each segment of the spinal cord, a pair of spinal nerves exits, allowing the nerve cells to communicate to the parts of the body in question.

Spinal Function

The primary function of the spinal cord is the transmission of communication. The spinal cord is an integral part of the central nervous system, which provides a conduit for communication between the brain and spine.

Your body has 31 very important pairs of nerves within the spinal column. These nerves are also referred to as mixed spinal nerves. These nerves provide many different functions, including motor skills, sensation, and other communication between the central spinal cord and the rest of the body.

Because the spinal cord consists of both vertebrae and nerves, many parts of it have neurological purposes. All along your spine, you have several nerves that control specific functions. These nerve groupings are referred to by their location along the spine.

Cervical Vertebrae: Controls functions to neck, arms, and legs.
Thoracic Vertebrae: Allows movement in the legs and trunk.
Lumbar and Sacral Vertebrae: Moderates movement in the legs, hips, and lower bodily functions.

Keep in mind that some functions are carried out by different parts of the spine at the same time. These groups work together to function. They provide movement and sensation. Damage to the spinal cord in these areas can impair bodily functions, including quadriplegia, paraplegia, and other loss of motor control.

Spinal Injury

Injuries to the spine are always dangerous. However, the effects are particularly devastating when centered in the spinal cord itself. The injury symptoms and the recovery process depend on the area of the spinal cord affected. For more information on this topic, please visit the Health Issues page.