Atrium (plural: atria): The upper chambers of the heart that receive blood returning from the body (right atrium) or lungs (left atrium).
Ventricle: The lower, more muscular chambers of the heart that pump blood out โ right ventricle to lungs, left ventricle to body.
Valve: A flap in the heart or veins that prevents the backflow of blood; ensures blood moves in one direction only.
Coronary artery: Blood vessels that supply the heart muscle itself with oxygenated blood; blockage leads to a heart attack.
Cardiac output: The volume of blood pumped by the heart per minute; calculated as heart rate multiplied by stroke volume.
Double circulation: The mammalian system in which blood passes through the heart twice for each complete circuit of the body โ once for pulmonary circulation (heart to lungs and back) and once for systemic circulation (heart to body and back).
This definitions covers Key Definitions within The Heart and Circulation for GCSE Biology. Heart structure, cardiac cycle, blood vessels, double circulation, heart rate control, and cardiovascular health It is section 8 of 15 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Practice questions for The Heart and Circulation
How many chambers does the human heart have?
Explain how the structure of an artery is related to its function.
Quick recall flashcards
What is diastole?
When the heart relaxes and the chambers fill with blood
What is systole?
When the heart contracts and pumps blood out of the ventricles