Adrenaline of epinephrine can be seen in autonomic neuropathy or following adrenalectomy. Failure of the adrenal cortex, as with Addisons disease, can suppress epinephrine secretion as the activity of the synthesing enzyme, phenylethanolamine-"N"-methyltransferase, depends on the high concentration of cortisol that drains from the cortex to the medulla. In 1901, Jokichi Takamine patented a purified extract from the adrenal glands, and called it "adrenalin" (from the Latin for "on top of the kidneys" ("ad" and "renal"), which was trademarked by Parke, Davis & Co in the US. The British Approved Name and European Pharmacopoeia term for this drug is hence "adrenaline".
Parasympathetic nervous system a healthy heart, the main pacemaker is a collection of cells on the border of the atria and vena cava called the sinoatrial node. Heart cells exhibit automaticity which is the ability to generate electrical activity independent of external stimulation. As a result, the cells of the node spontaneously generate electrical activity that is subsequently conducted throughout the heart, resulting in a regular heart rate. In absence of any external stimuli, sinoatrial pacing contributes to maintain the heart rate in the range of 60-100 beats per minute (bpm). At the same time, the two branches of the autonomic nervous system