Question

_____ is the ability of cardiac pacemaker cells to spontaneously initiate an electrical impulse without being stimulated from another source, such as a nerve.

a) Automaticity
b) Autonomy
c) Activity
d) Anomaly

Answer 1

Automaticity is the ability of cardiac pacemaker cells to initiate an electrical impulse without external stimulation. These cells are self-excitable and determine the heart rate.

Step-by-step explanation:

Automaticity is the ability of cardiac pacemaker cells to spontaneously initiate an electrical impulse without being stimulated from another source, such as a nerve. These pacemaker cells are self-excitable and can depolarize to threshold and fire action potentials on their own. This feature allows the heart to contract in a coordinated manner and determines the heart rate.