The Spinal Cord

The spinal cord is a bundle of nerves that connects the brain to other parts of the body. It is protected by a series of doughnut-shaped bones called vertebrae, which surround the spinal cord.

The human spinal cord is about 43-45 cm long and approximately as wide as a human finger. There are 13,500,000 neurons that transmit electro-chemical signals in the spinal cord. The cord weighs aproximately 35 grams. The vertebral column (bones) that supports it is about 70 cm long and has 31 segments and 31 pairs of spinal nerves.

Spinal Cord Vertebrae

• 7 cervical (neck) segments
• 12 thoracic segments
• 5 lumbar segments
• 5 sacral segments
• 4 fused coccygeal segment