Spinal Cord

Description of the Organ

The spinal cord is a long, thin, tube-like structure made of nervous tissue that extends from the base of the brain down to the lower back. It is a continuation of the brain and is responsible for transmitting messages between the brain and the rest of the body.

Morphology of the Spinal Cord

• The spinal cord is about 45 cm long in adults and tapers to a point at the lower end.
• It is surrounded by three protective membranes, the dura mater, the arachnoid mater, and the pia mater.
• The spinal cord has 31 pairs of spinal nerves that arise from it.

Structure in Transverse Section

• The spinal cord is divided into gray matter and white matter.
• The gray matter is located in the center of the spinal cord and contains the cell bodies of the nerve cells.
• The white matter is located on either side of the gray matter and contains the nerve fibers that carry signals to and from the brain.

Contents of Gray and White Matter

• Gray Matter:
  • Contains the cell bodies of the nerve cells.
  • Has a butterfly shape in the center of the spinal cord.
• White Matter:
  • Contains the nerve fibers that carry signals to and from the brain.
  • Has a horseshoe shape on either side of the gray matter.

Blood Supply of the Spinal Cord

• The spinal cord is supplied by two pairs of arteries: the anterior spinal artery and the paired posterior spinal arteries.
• The anterior spinal artery supplies the anterior two-thirds of the spinal cord.
• The paired posterior spinal arteries supply the posterior one-third of the spinal cord.

Applied Anatomy

• The spinal cord is responsible for controlling voluntary movements such as walking, talking, and writing.
• It also plays a role in controlling involuntary movements such as digestion and heart rate.
• Damage to the spinal cord can result in loss of sensation, paralysis, and other neurological problems.
• The spinal cord is also responsible for transmitting pain signals from the body to the brain.