14) The following excerpt, published on May 8, 2018, refers to a report on the conduction system in the heart entitled 'Conduction in the heart wal...

14) The following excerpt, published on May 8, 2018, refers to a report on the conduction system in the heart entitled 'Conduction in the heart wall: helical fibers minimizing diffusion deviation for polarization'.

The activation of the electrical signal in the ventricles begins at the points of insertion of the Pukinje network in the endocardium.
The diffusion component of the subsequent excitation wave propagates from the endocardium in a healthy heart wall without creating directional deviations.
This is a consequence of the particular geometric organization of the myocytes in the heart wall.
The heart of mammals must function as an efficient pump while conducting electronic signals to drive the contraction process.
The report discusses the use of radioisotopes in medical diagnosis and therapy.
A) The action potential in the cardiac muscle is initiated by the influx of calcium ions.
B) The depolarization of the cardiac muscle is caused by the influx of sodium ions.
C) The repolarization of the cardiac muscle is caused by the efflux of calcium ions.
D) The permeability of the membrane to potassium increases rapidly, and the loss of potassium through the membrane causes the repolarization of the cardiac muscle.
E) The permeability of the membrane to sodium increases rapidly, and the loss of sodium through the membrane causes the repolarization of the cardiac muscle.