Which of the following statements about the autonomic nervous system is true?

The autonomic nervous system (ANS) plays a crucial role in regulating involuntary physiological functions, including heart rate, digestion, respiratory rate, and pupillary response. It is divided into two main branches: the sympathetic and parasympathetic divisions, which have contrasting effects on bodily functions. The sympathetic division generally prepares the body for 'fight or flight' responses, while the parasympathetic division promotes 'rest and digest' activities.

The presence of these two divisions is essential for maintaining homeostasis and responding appropriately to the body’s needs and stressors. Since the statement accurately reflects the fundamental structure and function of the ANS, it stands as the correct choice. Understanding the division and its specific roles can greatly aid professionals in fields like cardiovascular perfusion, where managing physiological responses is critical during procedures.