The **central nervous system** is composed of the brain and the spinal cord. It performs to send messages, and processes as well as analyzes information that comes from the peripheral nervous system.

the sensory division is responsible for transmitting impulses from sense organs to the central nervous system. On the other hand, the motor division is responsible for transmitting impulses from the central nervous system to glands and muscles

The **cerebrospinal fluid** is a clear fluid located in the brain and spinal cord. It flows around these two organs and it plays a role in their protection against injuries by providing cushion and nutrients to them. The fluid specifically flows in the cranial and spinal subarachnoid spaces and as well as in the brain ventricles.

The **hypothalamus** is involved in many operations of the autonomous nervous system. This organ connects the endocrine and nervous systems. The **hypothalamus** is the small peanut-sized organ found in the brain, specifically inferior to the thalamus and superior to the pituitary gland. It is part of the limbic system that regulates the sleep-wake cycle, hunger, thirst, and fatigue.

Because the peripheral nervous system transmits reflex impulses from sense organs to the central nervous system and then back to the sense organs. Therefore, both the central nervous system and the peripheral systems are involved.

A larger cerebrum gives an advantage in cognitive performance which can result in higher survival potential because of the ability to adapt to the changes in time and environment. In course of evolution, it was found out that the larger the brains of the animals, the higher their chance to win over the competition with the smaller ones. Therefore, since birds’ cerebrum is smaller compared to humans, humans have a great advantage in terms of development as opposed to the bird species.