GENERAL HISTOLOGY

Detailed explanation-1: -Epinephrine and norepinephrine are very similar neurotransmitters and hormones. While epinephrine has slightly more of an effect on your heart, norepinephrine has more of an effect on your blood vessels. Both play a role in your body’s natural fight-or-flight response to stress and have important medical uses as well.

Detailed explanation-2: -Epinephrine increased cardiac output, stroke volume, and systolic ejection rate significantly without significant change in blood pressure. Myocardial O2 con-sumption increased in relation to increased kinetics of contraction.

Detailed explanation-3: -All doses of norepinephrine and the two higher doses of epinephrine increased mean arterial blood pressure and left ventricular max dP/dt. Heart rate increased with both drugs, more with epinephrine, but not beyond pre-intoxicated levels at any dose. Left ventricular end-diastolic pressure was unaltered by both drugs.

Detailed explanation-4: -Epinephrine alone increased heart rate and left ventricular end diastolic dimension and decreased left ventricular end systolic dimension. Left ventricular performance as assessed by fractional shortening and systolic blood pressure/end-systolic volume (P/V) ratio was also increased.