AEMCA Practice Exam

What body responses are stimulated by sympathetic activity?

1. Pupil constriction and bradycardia

2. Dilated pupils and tachycardia

3. Increased gastric motility and secretion

4. Heightened sleepiness and relaxation of muscles

The correct answer is: Dilated pupils and tachycardia

Sympathetic activity, which is part of the autonomic nervous system, prepares the body for "fight or flight" responses during stressful situations. It primarily stimulates processes that enhance an individual's ability to react to perceived threats. Dilated pupils and tachycardia are prominent responses of sympathetic activation. The dilation of pupils allows more light to enter the eyes, improving vision in low-light conditions, which is advantageous during emergencies. Tachycardia refers to an increased heart rate, facilitating greater blood flow to muscles and vital organs, thereby enhancing physical performance and responsiveness. In contrast, the other options describe opposite or irrelevant physiological responses influenced primarily by parasympathetic activity. For example, pupil constriction and bradycardia are associated with the body’s rest-and-digest functions rather than stress responses. Increased gastric motility and secretion, along with heightened sleepiness and relaxation of muscles, also align with parasympathetic stimulation, which promotes calmness and digestion rather than alertness and readiness for action.