SNS & PSNS
SYMPATHETIC NERVOUS SYSTEM: The SNS actions prepare the organism for physical or mental activity.
When facing a major stressor, the SNS orchestrates the response. It dilates the bronchi and the pupils, accelerates the heart rate and the respiration, and increases perspiration and arterial blood pressure, but reduces digestive activity.
Two neurotransmitters are primarily associated with this system: epinephrine and nor-epinephrine.
PARA-SYMPATHETIC NERVOUS SYSTEM: This system’s actions cause a general slowdown in the body’s functions in order to conserve energy.
Whatever was dilated, accelerated, or increased by the SNS is contracted, decelerated, or decreased by the PSNS.
The PSNS does augment digestive functions and sexual appetite. It’s main neurotransmitter is acetylcholine.
