Central Nervous System

The central nervous system (CNS) is a major division of the nervous system that consists of the brain and the spinal cord. It serves as the primary control center for the body, receiving and processing sensory information, initiating motor responses, and coordinating various bodily functions.

1. The Brain: This is the most complex part of the CNS, the brain contains several regions, each with specific functions, although they don't work in isolation; rather as an interconnected unit. Major components of the brain include the cerebrum (comprising the cerebral cortex, the basal ganglia, and the limbic system), the cerebellum, and the brainstem. The cerebrum is involved in higher cognitive functions, the cerebellum in coordination of movement, and the brainstem in regulation of vital life functions such as heart rate and respiration.

2. The Spinal Cord: This is the main pathway for communication between the brain and the peripheral nervous system (PNS). The spinal cord, encased in the vertebral column for protection, contains both sensory (afferent) and motor (efferent) neurons that transmit information to and from the brain.

The border between the CNS and peripheral nervous system (PNS) is generally considered to be the point where the nerve structures exit the bone of the spinal column or the base of the skull. In other words, once a nerve exits the spinal cord (CNS), it becomes part of the PNS^[1].

The central nervous system plays a critical role in maintaining overall body function and orchestrating complex processes necessary for human cognition, behaviour, and survival. It serves as the command center, receiving, processing, and integrating sensory information and initiating appropriate responses to maintain homeostasis and interact with the environment.