International A Level Biology / Mammalian transport systems

The cardiac cycle and the pressure graph

Edexcel International A Level Biology (YBI11), chapter 2: Mammalian transport systems, specification point 1.8. Part of the full course.

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The cardiac cycle is the sequence of contractions and relaxations that moves blood through the heart. Understanding how pressure changes control the valves helps you read a heart pressure graph and calculate heart rate.

More lessons in Mammalian transport systems

• Why many animals need a heart and circulation
• Blood and haemoglobin: carrying oxygen and carbon dioxide
• The oxygen dissociation curve
• The Bohr effect and fetal haemoglobin
• Arteries, veins and capillaries
• The structure of the mammalian heart
• Dissecting a mammalian heart
• How atherosclerosis develops
• Blood clotting and its role in CVD