| Flap 1 | Flap 2 |
| Nervous sytem | The body's principle control system. It regulates virtually all bodily functions via electrical impulses transmitted through nerves |
| Endocrine system | Closely related to the nervous system, however unlike the nervous system, it excerts its effect on the body through the release of speacialized chemical substances called hormones |
| Central nervous system (CNS) | Consists of brain and spinal cord |
| Peripheral nervous system (PNS) | Composed of cranial nerves and the peripheral nerves |
| Autonomic nervous system (ANS) | Controls automatic or involuntary functions |
| Somatic nervous system (SNS) | Controls voluntary motor funtctions |
| Sypathetic nervous system | "fight or flight" |
| Parasympathetic | "feed or breed" |
