The nervous system is like the body's main center for controlling and communicating information to our brains, while at the same time controlling vital functions such as our metabolism, heartrate and breathing! If we didn't have our nervous systems, we would essentially be an unconscious physical heap of cells, bones and flesh---dead matter! We'll talk more about terms such as arousal vs awareness in just a minute!
To start with, the nervous system consists of two main parts:
The Peripheral Nervous System: All our peripheral nerves that extend throuought our bodies and extremities.
The Central Nervous System: Mainly the Brain & Spinal cord as well as the Retina and Optic Nerve.
Image from: Vermis | anatomy | Britannica