Which structure connects the brain to the rest of the body?

• A. Ingestion, respiration, digestion, absorption
• B. Chewing, swallowing, digestion, excretion
• C. Inhalation, digestion, absorption, excretion
• D. Ingestion, digestion, absorption, egestion

Answer: (D)

The structure that connects the brain to the rest of the body is the spinal cord. It serves as the main highway for nerve signals between the brain and every part of the body. Motor commands originate in the brain and travel down the spinal cord to reach muscles, while sensory information from the body travels up the spinal cord to the brain. It runs protected inside the vertebral column, with spinal nerves branching out to limbs and organs. Quick reflexes can be triggered at the spinal level, without needing the brain to process the signal first.

The options shown describe digestive system activities (like ingestion, digestion, absorption, and egestion), which are about how food moves and is processed in the body, not about the neural connection between brain and body.