Many cells in the human body maintain an electric potential difference across their cellular membranes, typically through the use ion-specific pumps and channels that generate an excess of negative charges on the inside of the cellular membrane and an excess of positive charges on the outside. Let us estimate the total energy stored in the human body by this type of charge separation.

List two limitations of natural selection

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

About how much of the cell mass is watet