What is one primary effect of the sympathetic nervous system's activation during the "fight or flight" response?

The activation of the sympathetic nervous system during the "fight or flight" response leads to several physiological changes aimed at preparing the body to respond to perceived threats. One primary effect is enhanced blood flow to muscles. When the sympathetic nervous system is activated, it causes vasodilation in the blood vessels supplying skeletal muscles, thereby increasing blood flow. This enhanced blood flow delivers more oxygen and nutrients to the muscles, which is critical for activities requiring physical exertion, such as running or fighting.

In addition to increasing blood flow to muscles, the activation of the sympathetic nervous system also increases heart rate and respiratory rate to facilitate greater oxygen intake and deliver it efficiently to tissues throughout the body. Conversely, functions that are non-essential during a crisis, such as digestion, are reduced, resulting in decreased digestive activity. This prioritization of bodily functions underscores the efficiency of the sympathetic response in mobilizing resources for immediate physical action.