What effect does stimulation of the parasympathetic nervous system have on the digestive system?

Stimulation of the parasympathetic nervous system has a significant impact on the digestive system by enhancing its function. When the parasympathetic nervous system is activated, it promotes increased motility and secretions. This means that the movement of food through the digestive tract becomes more vigorous and coordinated, helping food to be effectively processed and absorbed. Additionally, the stimulation encourages the production of digestive enzymes and other secretions from glands in the gut, which are essential for breaking down food and facilitating nutrient absorption.

The other possible effects mentioned, such as decreased gas exchange or inhibition of digestive enzymes, do not align with the role of the parasympathetic nervous system in facilitating digestion. Similarly, a reduction in blood flow to the intestines runs counter to the expected response, as parasympathetic activation typically enhances blood flow to digestive organs to support their increased activity. Overall, the correct answer reflects the crucial role of the parasympathetic nervous system in promoting digestive processes.