What is the main component of the central nervous system aside from the spinal cord?

The main component of the central nervous system (CNS) aside from the spinal cord is the brain. The CNS is responsible for processing and integrating information, as well as coordinating responses to stimuli. It is composed of two main structures: the brain and the spinal cord. The brain itself is a complex organ that controls various functions, including thought, memory, emotion, sensory processing, and voluntary and involuntary movements.

In contrast, the peripheral nerves mentioned in another option are part of the peripheral nervous system, which connects the CNS to limbs and organs. Voluntary muscles are not a component of the CNS; instead, they are influenced by the CNS but reside in the muscular system. Autonomic ganglia also belong to the peripheral nervous system and are involved in involuntary functions, further distinguishing them from the components that constitute the CNS. Thus, the brain is the primary and most significant structure of the CNS after the spinal cord.