Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

The primary role of the sympathetic nervous system is to prepare the body for 'fight or flight' responses, which includes increasing heart rate. When the body perceives a threat or requires heightened awareness, the sympathetic nervous system kicks in, releasing neurotransmitters like norepinephrine that stimulate the heart to beat faster, thereby enhancing blood flow to vital organs and muscles. This physiological response is essential for dealing with emergencies or stress.

In contrast, options related to promoting digestion, reducing breathing rate, and enhancing rest and relaxation are functions associated with the parasympathetic nervous system. The parasympathetic system is responsible for conserving energy and facilitating bodily processes that occur during restful states, such as digestion and reduced heart rates. This highlights the distinction between the two branches of the autonomic nervous system and their opposing functions in regulating body processes.