Question

are structures that allow for one - way blood flow through the heart.
atria
ventricles
valves
capillaries

Explanation:

• Atria: Upper chambers of the heart, receive blood.
• Ventricles: Lower chambers, pump blood out.
• Valves: Ensure one - way blood flow (e.g., tricuspid, mitral, pulmonary, aortic valves).
• Capillaries: Small blood vessels for gas/nutrient exchange.

Answer:

Valves