Facts about the Spinal Cord
- 09
White matter comprising roughly 90 percent of the spinal cord's cross-sectional area consists of myelinated axons that form ascending and descending tracts, enabling rapid two-way communication between brain and body.
- 08
Gray matter in the spinal cord comprises roughly 10 percent of its cross-sectional area but contains the majority of neuronal cell bodies that coordinate reflex responses.
- 07
Spinal cord injuries affecting the thoracic region typically result in paraplegia, leaving lower limbs paralyzed while preserving upper body and arm function.
- 06
Syrinx formation, a cavity of fluid buildup within the spinal cord, can expand over years and destroy nerve fibers, sometimes occurring months or years after initial spinal cord injury.
- 05
Each spinal nerve root in humans contains approximately 10,000 to 100,000 individual axons, allowing the spinal cord to simultaneously relay thousands of distinct sensory and motor signals.
- 04
Cerebrospinal fluid bathes and protects the spinal cord by circulating continuously through the central canal, a narrow passageway running through its center.
- 03
Severe trauma to the spinal cord at C4 or higher can result in quadriplegia, affecting all four limbs and often requiring ventilator support for breathing.
- 02
In humans, the spinal cord extends approximately 18 inches from the brainstem to the lower back, containing gray matter that processes reflexes without requiring brain involvement.
- 01
Approximately 1 million nerve fibers bundle together within the spinal cord to transmit signals between the brain and body at speeds exceeding 250 miles per hour.