As the aroma of freshly brewed coffee drifted by dozing Henry's nose, his mouth started to water and his stomach began to rumble. Explain his reactions in terms of ANS activity.

The ANS controls involuntary bodily functions and is divided into the sympathetic and parasympathetic systems. It regulates activities like heart rate, digestion, and salivation without conscious effort, responding to internal and external stimuli.

The parasympathetic system promotes 'rest and digest' activities, stimulating salivation and increasing digestive secretions. When Henry smells coffee, this system activates to prepare the body for food intake, causing his mouth to water and stomach to rumble.

Sensory cues like the aroma of coffee can trigger conditioned reflexes via the ANS, linking smell to digestive responses. This learned association causes automatic physiological reactions, such as salivation and stomach activity, even before eating.