Which system connects to the spinal cord and branches out to every part of the body, serving as two-way communication?

• A. Central nervous system
• B. Endocrine system
• C. Autonomic nervous system
• D. Peripheral nervous system

Answer: (D)

Signals traveling between the brain or spinal cord and the rest of the body travel through the peripheral nervous system. This network of nerves branches out from the spinal cord and brain to reach every part of the body, enabling two-way communication: sensory information from the body to the CNS and motor commands from the CNS to muscles and organs. The central nervous system itself is the brain and spinal cord and doesn’t extend to every tissue, while the endocrine system uses hormones rather than neural signals. The autonomic nervous system is a part of the peripheral system that controls automatic functions, but the overall description of branching to every part of the body and supporting two-way neural communication fits the peripheral nervous system.