What is the function of the brain and nervous system?

• A. The heart pumps blood through the body.
• B. The brain regulates digestion only.
• C. The kidneys filter waste from the blood.
• D. The brain processes information and coordinates bodily functions, and the nervous system transmits signals between parts of the body.

Answer: (D)

The brain and nervous system act as the body's control and communication network. The brain processes information from senses, thoughts, memories, and goals, and then coordinates actions by sending commands to muscles and glands. The nervous system, made up of nerves and neurons, transmits these signals quickly between the brain and every part of the body, enabling movement, reflexes, and automatic processes like breathing and digestion. This coordination keeps the body responding appropriately to the environment and maintains internal balance.

Other statements refer to different body systems: the heart pumps blood (cardiovascular system), and the kidneys filter waste (urinary system). Digestion involves the digestive tract, though the nervous system can influence its rate and activity.