Which of the following is NOT a function of the parasympathetic nervous system?

The correct answer is that acceleration of heart rate is not a function of the parasympathetic nervous system. The parasympathetic nervous system is primarily responsible for promoting a state of rest and relaxation in the body, often referred to as "rest and digest." Its functions counterbalance those of the sympathetic nervous system, which is responsible for the body's fight or flight response.

In detail, the parasympathetic nervous system stimulates various activities that support digestion and energy conservation. For example, it promotes the stimulation of salivary glands, which aids in the digestion process by helping to break down food. It also causes constriction of the bronchi, which is part of the body's way of regulating airflow when in a relaxed state. Additionally, it facilitates digestion by increasing the activity of the gastrointestinal tract.

In contrast, acceleration of heart rate is a function associated with the sympathetic nervous system. When the body is faced with stress or danger, the sympathetic response activates the heart to pump faster, preparing the body for immediate action. Understanding the distinct functions of these two branches of the autonomic nervous system is crucial in fields like esthetics, where the physiological responses of the body can influence skin and health treatments.