In the mammal, the autonomic nervous system consists of

The autonomic nervous system in mammals is responsible for controlling involuntary functions such as heart rate, digestion, and breathing. It consists of two main components: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system prepares the body for "fight or flight" responses in times of stress, while the parasympathetic nervous system helps to regulate the body's "rest and digest" responses. Together, these systems work to maintain homeostasis in the body.