What does the autonomic nervous system control?

The autonomic nervous system (ANS) primarily regulates involuntary functions that are essential for maintaining homeostasis in the body. This includes activities that occur without conscious control, such as heart rate, blood pressure, respiration, digestion, and sexual arousal. The ANS operates automatically, managing essential bodily functions through its two branches: the sympathetic and parasympathetic nervous systems. The sympathetic system prepares the body for "fight or flight" responses, increasing heart rate and energy expenditure, while the parasympathetic system promotes "rest and digest" functions, conserving energy and restoring the body to a state of calm. These involuntary functions are crucial for survival and are not influenced by voluntary control, which is why this option accurately describes the primary role of the autonomic nervous system.