Cardiovascular System I: The Beating Heart
Concept 2: The Cardiac Cycle
Practice (1 page)
Review (1 page)
Review (1 page)
Concept 2: The Cardiac Cycle
The chambers of the heart alternately contract and relax in a rhythmic cycle.
• During the period of contraction (systole), the heart pumps blood out through the arteries; during the period of relaxation (diastole), the heart fills with blood.
• One complete sequence of filling and pumping blood is called a cardiac cycle, or heartbeat.
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