Answer:
The correct answer to the question: Energy for contraction of myocardial cells comes primarily from:___, would be, A: aerobic respiration in the mitochondria.
Explanation:
In order for the heart muscles (myocardium) to contract, there are a series of elements that need to be present. One of them, and most vital, is calcium, which will activate the connection of myosin and actin, the filaments in cardiomyocytes, the very units of muscular tissues in the heart. However, even if calcium were present, without ATP, the molecule of energy that will allow the process to happen, then contractions would not be possible. There simply would not be energy to allow the chemical reactions. The one organelle within the cell that is responsible to ensure there is ATP available, is the mitochondria. This production of ATP by mitochondria, happens through the process of aerobic respiration. This is why the answer is A.
