Comparative Effects of Epinephrine and Norepinephrine

• Blood vessels

  Epinephrine: Vessels in skeletal muscle vasodilate, decreasing resistance to blood flow

  Norepinephrine: Blood flow to skeletal muscles increases, resulting from constriction of blood vessels in skin and viscera
• Heart

  (Epinephrine & Norepinephrine)

  • Rate increases
  • Force of contraction increases
• Systemic blood pressure

  Epinephrine: Some increase due to increased cardiac output

  Norepinephrine: Great increase due to vasoconstriction, counteracted in muscle blood vessels during exercise
• Airways

  Epinephrine: Dilated

  Norepinephrine: Some dilation
• Reticular formation of brain

  Epinephrine: Activated

  Norepinephrine: Little effect
• Liver

  Epinephrine: Promotes breakdown of glycogen to glucose, increasing blood sugar level

  Norepinephrine: Little effect on blood glucose level
• Metabolic rate

  (Epinephrine and Norepinephrine)

  Increases