How does the sympathetic nervous system affect the body during stress?

The sympathetic nervous system plays a crucial role in the body's response to stress by preparing it for 'fight or flight' situations. This activation leads to a range of physiological changes aimed at enhancing the body's ability to respond rapidly to perceived threats. For instance, it increases heart rate and blood pressure, dilates airways, and boosts energy supplies by stimulating the liver to release glucose. Additionally, it temporarily inhibits non-essential functions such as digestion, allowing the body to focus its resources on immediate survival.

In contrast, other responses such as promoting relaxation and recovery, enhancing digestive processes, and lowering heart rate and blood pressure are functions of the parasympathetic nervous system, which calms the body down after a stressful event. Thus, the sympathetic nervous system's role in stress situations is critical for survival, as it primes the body for action.