Explanation

Sympathetic nervous system (SNS) is the autonomous nervous system with adrenergic nerve fibres, which release ‘adrenaline’. It increases the functioning of visceral organs. It increases heart beat, respiration, dilates the pupil, rises blood pressure, etc. It controls the secretion of adrenaline by adrenal medulla, functions as emergency hormone. It induces fight, flight and fright reactions. Watching a horror movie or under stress conditions, sympathetic nervous system is activated secreting adrenaline. It causes high heart beat, high respiration and inhibits the salivation and secretion from digestive glands making mouth dry.