The Cardiac Electrical Impulse Normally Begins Spontaneously in the Sinoatrial

Multiple Choice

The cardiac electrical impulse normally begins spontaneously in the sinoatrial (SA) node because it:

A) has a superior location in the right atrium.
B) is the only area of the heart capable of spontaneous depolarization.
C) has rich sympathetic innervation via the vagus nerve.
D) depolarizes between -50 and -60 mV, rather than between -60 and-70 mV.