Sympathetic Nervous System

How does the Sympathetic Nervous System affect the body.

The sympathetic is the body’s response to a perceived threat. It is all so known as the fight or flight response. Sympathetic responses will increase heart rate and contraction, increase breathing rate and dilate the bronchial so more air can get into the lungs with oxygen and get carbon dioxide out. The sympathetic will dilate vessel to the necessary organs for survival like the brain, heart, lungs, muscles and constrict blood vessels not critical to lief like the digestive system.

  • increases the heart
  • increases the constriction of the heart
  • dilation of the bronchial in the lungs
  • dilation of the pupils
  • contraction of muscles
  • Shunts blood to major organs like brain, lungs, heart, muscels.
  • releases adrenaline from the adrenal gland
  • shuts down the processes not critical to survival
  • Decrease saliva, digestion, urinary output


How Your Body Controls Breathing. (2022, March 24). NHLBI, NIH.