Autonomic Nervous Functions

Definition: Autonomic nervous functions are involuntary vital functions regulated by the autonomic nervous system (ANS), and consist of heart functioning, digestive functioning and glandular functioning. During the fight-or-flight response, the ANS automatically alters the functioning of these systems in response to perceived threat, preparing your body to fight or run. Heart rate increases, blood flow is shunted to the major muscle groups, digestive activity slows, blood pressure rises, and other changes occur. After the body no longer feels threatened, these functions return to their regular level of functioning; this change is known as the .