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".
Central nervous system fatigue increases the amount of perceived effort an individual experiences. By forcing the body through a higher perceived intensity, the individual becomes more likely to cease exercise by means of exhaustion. Perceived effort is greatly influenced by the intensity of corollary discharge from the motor cortex that affects the primary somatosensory cortex. Endurance athletes learn to listen to their body. Protecting organs from potentially dangerous core temperatures and nutritional lows is an important brain function. Central nervous system fatigue alerts the athlete when physiological conditions are not optimal so either rest or refueling can occur. It is important to avoid hyperthermia