Which system is responsible for inhibiting gastrointestinal activity?

The sympathetic nervous system is responsible for inhibiting gastrointestinal activity. This system is part of the autonomic nervous system and plays a crucial role in the body's response to stress or emergencies, often referred to as the "fight-or-flight" response. When the sympathetic nervous system is activated, it prioritizes energy allocation towards systems necessary for immediate survival, such as increasing heart rate and redirecting blood flow to muscles, while diverting resources away from non-essential functions like digestion.

Through this mechanism, the sympathetic nervous system effectively lowers gastrointestinal motility and secretions, allowing the body to focus on responding to perceived threats rather than performing digestive processes. This is a physiological adaptation that ensures survival in moments of stress, underlining the importance of this system in regulating gastrointestinal activity. The other systems listed do not inhibit gastrointestinal activity in this manner.