An organ system consists of a group of organs that performs specific functions necessary for the survival of an organism. Humans have eleven different organ systems: integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, digestive, urinary, and reproductive. Discuss the function of neurons, the brain and the spinal cord within the human nervous system while explaining the interrelationship of each organ.

The nervous system includes the brain, spinal cord, and a complex network of neurons. This system is responsible for sending, receiving, and interpreting information from all parts of the body. The nervous system monitors and coordinates internal organ function and responds to changes in the external environment.

• Neurons are the basic unit of the nervous system. All cells of the nervous system are comprised of neurons. Neurons contain nerve processes which are "finger-like" projections that extend from the nerve cell body. The nerve processes consist of axons and dendrites which are able to conduct and transmit signals.

• The brain is the control center of the body. One of these furrows, the medial longitudinal fissure, divides the brain into left and right hemispheres. Covering the brain is a protective layer of connective tissue known as the meninges.

• The spinal cord runs down the center of the protective spinal column extending from the neck to the lower back. Spinal cord nerves transmit information from body organs and external stimuli to the brain and send information from the brain to other areas of the body.