<prompt> All of the following are true about cardiac muscles, EXCEPT:Abundant mitochondria are present.Has high content of myoglobin10 energy is provided by anerobic metabolismNone of the above  <response>: Mammalian heas have an abundant blood supply, numerous mitochondria, and a high content of myoglobin, a muscle pigment that can function as an O2 storage mechanism. Normally, less than 1 of the total energy liberated is provided by anaerobic metabolism. Ref: Ganongs Review of Medical Physiology 23rd edition, Chapter 5. 