Chapter 10 of 14All chapters
Chapter 10 of 14
The nervous system
Signals, reflexes and control.
Two divisions
The central nervous system is the brain and spinal cord. The peripheral system is everything else, carrying signals in from the senses and out to the muscles.
- Signals travel as electrical impulses and cross gaps between cells as chemicals.
- A reflex loops through the spinal cord alone, which is why it happens before you notice.
Automatic control
The autonomic system runs the things you never think about. Its sympathetic half prepares for effort and the parasympathetic half handles rest and digestion.