Tag: neural control and coordination

White matter is a component of the central nervous system, in the brain and spinal cord, and consists mostly of glial cells and myelinated axons that transmit signals from one region of the cerebrum to another and between the cerebrum and lower brain centers.

As a matter of fact, the central nervous system is one of the best-protected systems in the entire body, defended by the bones of the skull and spinal column. Unfortunately, when these bones are injured or fractured they can compromise the soft tissue in the spinal cord, causing permanent damage. If you strain a muscle, it repairs itself. But the spinal cord is different. That's because some of the cells in the central nervous system are so complex and specialized that they don't have the ability to regenerate. 

The ventral root (motor root) of each spinal nerve consists of axons from motor neurons, whose cell bodies are found within the grey matter of the spinal cord. A ventral root and a dorsal root unite to form a spinal nerve, which passes outward from the vertebral canal through an intervertebral foramen.

The grey matter, in the center of the spinal cord, is shaped like a butterfly and consists of cell bodies of interneurons and motor neurons, as well as neuroglia cells and unmyelinated axons. Projections of the grey matter (wings) are called as horns. Together, the grey horns and the grey commissure form the "grey H."

A posterior root ganglion (spinal ganglion) (also known as a dorsal root ganglion), is a cluster of nerve cell bodies (a ganglion) in a posterior root of a spinal nerve. The axons of posterior root ganglion neurons are known as afferents. The posterior root ganglia lie along the vertebral column by the spine. The nerve endings of posterior root ganglion neurons have a variety of sensory receptors that are activated by mechanical, thermal, chemical, and noxious stimuli.