The Nervous System

Cooperation for Coordination

Neurons are amazing ... advanced ... powerful. But they can't do anything by themselves. Each individual cell needs to cooperate with others to do its job and needs support from other types of cells to remain healthy and functional.

A group of cells working together is called a tissue. Here are some examples of nervous tissue:

• Gray matter - cells without insulation, tightly packed in your brain and in the inner part of your spinal cord. Gray matter is like an integrated circuit, connecting and processing information.
• White matter - cells insulated by a substance called myelin. White matter in the brain or in the outer portion of the spinal cord usually carries messages faster and farther.
• Neuroglial cells - these cells support and nourish the nerve cells. They include astrocytes, which provide support; oligodendrocytes, which form the myelin; and microglia, which produce antigens and destroy bacteria.

Tissues combine to form organs. The nervous system is not just built from neurons. There are also cells that don't communicate, but wrap around the neurons to nourish and protect them, called Schwann cells. The organs of the nervous system work together to coordinate body processes.

The spinal cord conducts messages from all parts of the body. It also integrates messages for quick response as simple reflexes.

The brain integrates higher order messages and records them for short and long term memory. The brain's hypothalamus communicates directly with the glands of the endocrine system, so that nervous inputs can result in chemical messages.

Sense organs (like the eyes, nose, and tongue) receive specialized messages to send them to the brain.