The spinal cord is a tubular bundle of nervous tissue and it supports cells that extends from the brain. The brain and spinal cord together make up the central nervous system.
It starts at the occipital bone and extends down to the space between the first and second lumbar vertebrae. the spine does not extend the entire length of the vertebral column.
- In men it is about 18 inches or 45 cm
- In women it is about 17 inches or 43 cm.
- It ranges from 1/2 inch thick in the cervical and lumber regions to 1/4 inch in the thoracic area.
Protected by the vertebral column it’s primarily function is the transmission of neural signals between the brain and the body. It has neural circuits that can independently control many reflexes and central pattern generators. There are three major functions of the spinal cord:
- As a conduit for motor information
- As a conduit for sensory information
- A center for coordinating certain reflexes
The spinal cord is described in three parts and each has a level of body function as follows:
- Neck flexors
- Neck extensors
- Supply diaphragm
- Shoulder movement, raise arm, flexion of elbow, externally rotates the arm
- Extends elbow and wrist
- Flexes wrist
- Flexes wrist
- Supply small muscles of the hand
- intercostal and trunk above the waist
- Abdominal muscles
- Thigh flexion
- Thigh adduction
- Extension of the leg at the hip and knee
- Flexion of the leg at the knee
- Dorsiflexion of the foot
- Extension of the toes
- Plantar flexion of the foot