Which system is responsible for controlling involuntary functions such as heart rate and digestion?

The autonomic nervous system is responsible for overseeing involuntary functions that are essential for maintaining homeostasis within the body. This system controls processes that occur without conscious thought, such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. It is divided into two main branches: the sympathetic nervous system, which prepares the body for "fight or flight" responses, and the parasympathetic nervous system, which promotes "rest and digest" activities.

The central nervous system, which comprises the brain and spinal cord, is primarily involved in processing information and coordinating responses, rather than directly controlling involuntary functions. The peripheral nervous system serves as a communication line between the central nervous system and the rest of the body but includes both voluntary (somatic) and involuntary (autonomic) systems. The somatic nervous system, on the other hand, is responsible for voluntary movements and the control of skeletal muscles, which is in contrast to the autonomic nervous system that manages involuntary actions.