Which function is associated with the brain stem?

• A. part of the nervous system; cord, life support, respiration, heartbeat, active during sleep
• B. thought processing and memory
• C. digestion
• D. regulate hormones

Answer: (A)

The brain stem is responsible for the body's most basic, life-sustaining functions. It sits at the base of the brain, right above the spinal cord, and serves as the main conduit for signals between the brain and the body. Within it, centers in the medulla control breathing and heart rate, while the pons and the reticular formation help coordinate respiration and regulate wakefulness and sleep. These automatic functions are essential for staying alive, so this description best matches what the brain stem does.

Thought processing and memory involve the cerebral cortex and hippocampus. Digestion is largely controlled by the autonomic nervous system and gut, but not primarily by the brain stem. Hormone regulation centers are in the hypothalamus and pituitary.