The major parts of the human neural system are depicted below. Fill in the empty boxes with appropriate words.

(N/A) The human neural system is divided into two main parts: the Central Neural System $(CNS)$ and the Peripheral Neural System $(PNS)$.
$1$. The $CNS$ consists of the brain and the spinal cord.
$2$. The $PNS$ is further divided into the somatic neural system and the autonomic neural system.
$3$. The brain is divided into the forebrain,midbrain,and hindbrain.
$4$. The autonomic neural system is further classified into the sympathetic neural system and the parasympathetic neural system.
Following the hierarchy:
- The box next to $CNS$ is $PNS$.
- Under $CNS$,the box next to Brain is Spinal cord.
- Under $PNS$,the box next to Autonomic neural system is Somatic neural system.
- Under Brain,the boxes are Forebrain,Midbrain,and Hindbrain.
- Under Autonomic neural system,the box next to Sympathetic neural system is Parasympathetic neural system.