The Aword

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Physiological Effects

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The sympathetic nervous system mediates the body's response to arousal/activity/anger/fear/stress.

Primary target organs are:

  • Heart, blood vessels >> increased heart rate and force, constriction of peripheral blood vessels and those in the gut to allow greater supply to muscles
  • Lungs >> dilation of airways for easier breathing
  • Smooth muscle in organs>> reduced gut function; pupil dilation; bladder sphincter closed; goosebumps
  • Glands (sweat, salivary, digestive); reduced urine secretion; sweat on palms and other sites ("adrenergic sweating")
  • Metabolic tissue (fat cells, liver)>> increased blood sugar
  • Ejaculation

The parasympathetic system returns the body to ?steady state':

  • Heart rate decreases
  • Bronchial muscle relaxes
  • Pupil constricts
  • Bladder sphincter relaxes
  • Digestive functions resume
  • Penile erection

This is a rather simplified picture.