Medical Dictionary. arrhythmia. play. noun arÂ·rhythÂ·mia \Ä-Ërith-mÄ-É\. Medical Definition of arrhythmia. : an alteration in rhythm of the heartbeat either in time or force.
Central metabolism provides mechanisms for the generation of energy from carbon-energy source catabolism and the production of biosynthetic precursors and intermediates for the anabolic pathways essential to maintain cell structure and function.
Caffeine is classified as a central nervous system stimulant and it belongs to xanthine chemical group. There are three distinguished compounds in xanthine group: Caffeine: 1,3,7-trimethylxanthine. Sources: Coffee, tea, cola nuts, mate, guarana.