Final answer:
The sympathetic nervous system is responsible for the "fight or flight" response when an organism faces a threat, preparing the body to take action by accelerating the heart rate and inhibiting digestion.
Step-by-step explanation:
The sympathetic nervous system is sometimes referred to as the "fight or flight" nervous system due to its activation when an organism faces a potentially threatening situation. In such scenarios, the body undergoes several physiological changes that prepare it for either facing the danger or escaping from it. For example, heart rate accelerates and digestion is inhibited, allowing more blood and energy to be directed towards muscles.
To answer the student's question precisely, the sympathetic nervous system is the component of the autonomic nervous system that is responsible for the fight or flight response. While the somatic nervous system controls voluntary movements and the parasympathetic nervous system is involved in rest and digest functions, it is the sympathetic division that prepares the body for action during high-stress situations. This quick and involuntary reaction is essential for survival, aiding an organism to respond to threats efficiently.
The sympathetic nervous system is activated in response to stressful situations and triggers the fight or flight response by preparing the body to either confront or flee from a threat.