• α 1 receptors: Arteriolar walls – SNS – increased peripheral vascular resistance.
• ß 1 receptors: Heart – SNS – increased HR, contractility, speed of conduction.
• ß 2 receptors: Vascular beds, e.g. muscles, lungs and heart leads – SNS – vasodilatation.

Effects of the sympathetic nervous system on the cardiovascular system

• ß1 & ß2
  Both increase heart rate, contractility and speed conduction
• ß2
  Stimulation leads to vasodilation
• α1
  Stimulation causes vasoconstriction

Sympathetic neurotransmitters are noradrenaline and adrenaline