Axons form nerves in

Provide information on the evolution of the neural system in animals.

$P$ - The nervous system that relays impulses from the $CNS$ to skeletal muscles.
$Q$ - The nervous system that transmits impulses from the $CNS$ to involuntary organs and smooth muscles of the body.
$\quad\quad\quad P \quad\quad Q$

Contraction of involuntary muscles, secretion of digestive glands and rate of heart beats are under the control of

The autonomic neural system is a division of

Which system is responsible for the conservation of energy?