Why Do We Think

Major Division Of The Nervous System
There are two major divisions of the nervous system, central nervous system (CNS) & peripheral nervous system (PNS). The best way I can explain the Central nervous system is as my Division Headquarters. The Command in General is the Brain. He/she holds all the information in their location to send out to the Battalion Headquarters.
The peripheral nervous system (PNS) can be best explained by the Battalion Headquarters. The Battalions provide all the information to the Division on where it stands as an Army during war & peace time. With all the information that the Division receives from the Battalion, the Command in General can make discussion based upon how the Battalion is working and functioning as a whole.

Structure Of The Brain.
The brain has three major brain structures, brain stem, limbic system, & the cerebrum.   Within the brain stem you have the medulla, pons, reticular formations & thalamus.   The medulla is on top of the spinal cord which helps assist the body to properly function. Then the pons is the bridge gateway to input information into your brain. Reticular formation helps keep your body stay alert. The cerebellum helps the body move and function.
Within the limbic system you have hippocampus, amygdala,   & hypothalamus. The hippocampus helps you with your memories. The amygdala keeps your emotions under control. Hypothalamus has an important part in your brain structure by process in intent behavior.
The cerebrum has the corpus callosum which passes information back & fourth between your brain. The frontal lobe helps you make decisions, gives you the drive to meet your goals, & helps you make important decisions in everyday life. Parietal lobe helps with touch & temperature. Occipital lobe is for processing information by what you see. Temporal lobe helps with processing information by hearing.