AEMCA Practice Exam

What does parasympathetic activity predominantly stimulate?

1. Increased heart rate and pupil dilation

2. Pupil constriction and increased gastric mobility

3. Reduced secretion and bronchodilation

4. Increased gastric motility with pupil dilation

The correct answer is: Pupil constriction and increased gastric mobility

The correct choice highlights the key features of parasympathetic activity within the autonomic nervous system. The parasympathetic division primarily functions to promote a "rest and digest" state in the body. It is responsible for activities that occur when the body is in a relaxed state. Pupil constriction, or miosis, is a direct effect of parasympathetic stimulation. This response is mediated by the sphincter muscle of the iris, which is activated to decrease the size of the pupil and thus allow less light into the eye, enhancing close-up vision and protecting the retina from excess light. Increased gastric motility refers to the enhanced movement within the stomach and intestines, which aids in digestion and promotes peristalsis. The parasympathetic system achieves this through the release of acetylcholine, which stimulates the muscles and glands in the gastrointestinal tract. This combination of pupil constriction and increased gastric motility reflects the body's shift towards maintenance and nourishment, keeping energy consumption at a manageable level while promoting digestive function. In contrast, the other selections incorrectly represent the actions of the parasympathetic system. For instance, increased heart rate and pupil dilation are more aligned with sympathetic activity, which prepares the body for "fight