Question

multiple choice question
electrical activity is started at the sa node, which causes an action potential to spread through the heart through the

o cardiac cycle
o blood flow
o conduction system
o internal skeleton

Explanation:

The sino - atrial (SA) node is the heart's natural pacemaker. Electrical activity generated here spreads through the heart's conduction system, which includes structures like the atrioventricular (AV) node, bundle of His, and Purkinje fibers. The cardiac cycle refers to the sequence of events in a single heartbeat, blood flow is the movement of blood through the heart and body, and the internal skeleton of the heart provides structural support, not a pathway for electrical activity.

Answer:

O conduction system