A 19-year-old female college student presents to the campus health clinic after fainting during a biology lab while watching a dissection. She reports feeling nauseous, sweaty, and light-headed just before collapsing. Witnesses noted she was unconscious for less than a minute and recovered fully within a few minutes without intervention. Her vital signs are now normal, and she has no history of cardiac issues. The physician suspects vasovagal syncope triggered by the stressful event. In this patient with suspected vasovagal syncope following a stressful trigger, which of the following best describes the underlying mechanism and characteristic features?
