Which structures are part of the nervous system?

• A. Brain, Spinal cord, Nerves
• B. Heart, Blood Vessels
• C. Lungs, Trachea
• D. Muscles and bones

Answer: (A)

The nervous system is the body's communication network that coordinates thoughts, senses, and movements. The brain is the control center that processes information and makes decisions. The spinal cord acts as the main highway linking the brain with the rest of the body, relaying signals up and down. Nerves are bundles of neurons that extend throughout the body, carrying messages to muscles, glands, and sense organs. Together, these structures form the nervous system.

The other structures belong to different body systems: the heart and blood vessels are part of the circulatory system, lungs and trachea are part of the respiratory system, and muscles and bones belong to the musculoskeletal system. The nerves interact with muscles for movement, but the bones and muscles themselves are not parts of the nervous system.