What term describes the brain and spinal cord collectively?

The brain and spinal cord are collectively referred to as the central nervous system (CNS). This term encompasses the primary structures responsible for processing and transmitting neural information throughout the body. The central nervous system plays a critical role in integrating sensory information, coordinating responses, and overseeing higher functions such as cognition and emotions.

In contrast, the peripheral nervous system involves all the nerves outside the central nervous system and serves to connect the CNS to the limbs and organs. The autonomic nervous system is a branch of the peripheral nervous system that regulates involuntary bodily functions. Meanwhile, the somatic nervous system mainly controls voluntary movements and the reflex arcs associated with skeletal muscles. Understanding these definitions and distinctions reinforces the significance of the central nervous system in the overall framework of the nervous system.