This is the first tutorial in the cardiovascular assessment module. In the tutorial I discuss heart rate, how it originates and how it is controlled. This is principally a discussion about sinus bradycardia and sinus tachycardia. I go on to discuss the parasympathetic nervous system and the sympathetic nervous system, how they function physiologically and how they are impacted by drugs that we administer and disease processes. I provide a detailed discussion of adrenoceptor agonists and antagonists.