The broadest way to classify the nervous system is to differentiate between the nervous systems.

Central and Peripheral

Explanation:

The nervous system is divided into two parts: the central nervous system and the peripheral nervous system. The central nervous system includes the brain and spinal cord.

On the other hand the peripheral nervous system includes all of the nerves that branch out from the brain and spinal cord and extend to other parts of the body including muscles and organs. Each part of the system plays a vital role in how information is communicated throughout the body.

The below diagram provides a schematic view of the role of each sub-division  of the Nervous System.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation

answer:   option a) glucagon was secreted by his pancreas before he ate the cookies because blood glucose was low. insulin was secreted after he ate the cookies because his blood glucose was high.

explanation: