AQA · GCSE · Biology

    Course version: 8461 · Version from Sept 2018

    The heart is an organ that pumps blood around the body in a double…

    Full specification wording

    The heart and blood vessels: The heart is an organ that pumps blood around the body in a double circulatory system.

    The heart is an organ made mainly of cardiac muscle, which contracts rhythmically to pump blood.

    Checked against the AQA 8461 specification (opens in a new tab) on .

    • Point 2 of 11
    • 4 key terms

    Study notes

    From the checked teaching notes for this specification point.

    The idea

    The heart is an organ made mainly of cardiac muscle, which contracts rhythmically to pump blood. In a double circulatory system, blood passes through the heart twice for each complete circuit of the body. The right side pumps deoxygenated blood to the lungs in the pulmonary circuit; the left side pumps oxygenated blood around the body in the systemic circuit. This arrangement maintains a high pressure for the body while protecting the lungs from excessive pressure.

    What earns the marks

    • States that the heart is an organ made of cardiac muscle that contracts to pump blood.
    • Defines a double circulatory system as blood passing through the heart twice per complete circuit.
    • Traces the pulmonary circuit from the right side to the lungs and back to the left side.
    • Traces the systemic circuit from the left side around the body and back to the right side.
    • Explains that separating the circuits maintains higher pressure for the body while limiting pressure to the lungs.

    Common mistakes and how to put them right

    • Saying blood passes through the heart once per circuit.

      Put it right by stating it passes through twice.

    • Mixing up the pulmonary artery and pulmonary vein.

      Put it right by noting the artery carries deoxygenated blood to the lungs and the vein returns oxygenated blood.

    • Thinking the left side pumps to the lungs.

      Put it right by stating the right side pumps to the lungs and the left side pumps to the body.

    Exam tips

    • Use a flow diagram or numbered sequence to show the double circuit clearly.
    • Name the four main vessels in the correct order when tracing blood flow.
    • When explaining the advantage, compare pressure in the lungs with pressure in the body.

    Try the lesson

    The start of the The heart and blood vessels: The heart is an organ that pumps blood around the body in a double circulatory system. lesson, made from checked teaching notes for this specification point.

    Have a go first

    What is the main function of the heart in the human body?

    Listen

    The heart is an organ made mainly of cardiac muscle, which contracts rhythmically to pump blood. In a double circulatory system, blood passes through the heart twice for each complete circuit of the body. The right side pumps deoxygenated blood to the lungs in the pulmonary circuit; the left side pumps oxygenated blood around the body in the systemic circuit. This arrangement maintains a high pressure for the body while protecting the lungs from excessive pressure. A strong answer earns marks for these points. States that the heart is an organ made of cardiac muscle that contracts to pump blood. Defines a double circulatory system as blood passing through the heart twice per complete circuit. Traces the pulmonary circuit from the right side to the lungs and back to the left side. Traces the systemic circuit from the left side around the body and back to the right side. A common slip: Saying blood passes through the heart once per circuit. Instead, stating it passes through twice. Exam tip: Use a flow diagram or numbered sequence to show the double circuit clearly.

    See it

    A flowchart with eight nodes arranged in a loop. The right side of the heart leads to the pulmonary artery, which leads to the lungs, which lead to the pulmonary vein, which leads to the left side of the heart, which leads to the aorta, which leads to the body, which leads to the vena cava, which leads back to the right side of the heart. This shows blood passing through the heart twice in one complete circuit.
    Shows the double circulatory system, with blood passing through the right side to the lungs and back to the left side, then around the body and back to the right side.

    Key words

    Say what each word means before you turn the card.

    Double circulatory system

    Try answering aloud or in your head before turning the card.

    Pulmonary circuit

    Try answering aloud or in your head before turning the card.

    Systemic circuit

    Try answering aloud or in your head before turning the card.

    Heart

    Try answering aloud or in your head before turning the card.

    See every definition
    Double circulatory system
    A system in which blood passes through the heart twice for each complete circuit of the body.
    Pulmonary circuit
    The circuit in which the right side pumps deoxygenated blood to the lungs and back to the left side.
    Systemic circuit
    The circuit in which the left side pumps oxygenated blood around the body and back to the right side.
    Heart
    An organ made mainly of cardiac muscle, which contracts rhythmically to pump blood.

    Label the diagram

    Some boxes have lost their names. Pick the right name for each number.

    The diagram again, with 3 boxes numbered instead of named. A flowchart with eight nodes arranged in a loop. The right side of the heart leads to the pulmonary artery, which leads to the lungs, which lead to the pulmonary vein, which leads to the left side of the heart, which leads to the aorta, which leads to the body, which leads to the vena cava, which leads back to the right side of the heart. This shows blood passing through the heart twice in one complete circuit.

    • 1Box 1

    • 2Box 2

    • 3Box 3

    0 of 3 labelled

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