When a student nurse asks the nurse how the cardiac electrical impulse normally begins,what is the most correct response? 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 more rapidly than other automatic cells of the heart

Question

Quizplus · Accepted Answer

The electrical impulse normally begins in the SA node because its cells depolarize more rapidly than other automatic cells.
Cardiac impulses occur in the SA node because its cells depolarize more rapidly than other automatic cells,not because of its superior location.
Cardiac impulses occur in the SA node because its cells depolarize more rapidly than other automatic cells.The SA node is not the only area of the heart capable of spontaneous depolarization.
Cardiac impulses occur in the SA node because its cells depolarize more rapidly than other automatic cells.It does have rich innervations,but by parasympathetic innervation from the vagus nerve.

When a Student Nurse Asks the Nurse How the Cardiac