NUR 259 Lecture Notes - Lecture 1: Beta Blocker, Vascular Smooth Muscle, Sympathetic Nervous System
Document Summary
Beta blockers block the beta receptors sites in the body so norepinephrine and epinephrine can not bind to the receptor site and elicit a sympathetic nervous system response. Sympathetic nervous system: it"s the fight or flight system . it works to save your life from danger. When beta receptors sites are stimulated by the sns and have norepinephrine and epinephrine bind to them, the person can experience (note these are just some of the responses created by the sympathetic nervous system): Increase heart rate and blood pressure: this increases cardiac output and the workload on the heart, but it requires a lot of oxygen demand by the myocardium. Increase strength of heart contractions: this helps to increase cardiac output, bronchodilation, the bronchioles will dilate so breathing can be easier and more oxygen can enter the blood. Remember this oxygen is needed because the myocardium demands it for this type of nervous system response.
