CK12 Life Science

(Marvins-Underground-K-12) #1

William Harvey. In 1616, Harvey first described the pulmonary and systemic circulation
systems in detail.


Lesson Summary



  • The heart is divided into four chambers, the left and rightatriaand the left and right
    ventricles.The right side of the heart collects deoxygenated blood from the body and
    pumps it into the lungs where it releases carbon dioxide and picks up oxygen. The
    left-side carries the oxygenated blood back from the lungs, into the left side of the
    heart which then pumps the oxygenated blood throughout the rest of the body.

  • The valves in the heart prevent blood from flowing backward into the heart. The
    contraction rate of cardiac muscle is controlled by two small groups of cardiac muscle
    cells called thesinoatrial(SA) andatrioventricular(AV) nodes.

  • The heart has its own blood supply, which is called the coronary circulation. The
    heart is fed oxygen-rich blood by coronary arteries. Oxygen-poor blood is collected by
    coronary veins.


Further Reading / Supplemental Links



Review Questions



  1. Name the four chambers of the heart.

  2. Where does oxygen-poor blood first enter the heart?

  3. Do ventricles pump blood out of the heart or do they pump blood into the atria?

  4. What is the purpose of the valves in the heart?

  5. What do the AV valves do?

  6. Does the vena cava carry oxygen-poor or oxygen-rich blood?

  7. Why can the heart be considered to be two separate pumps?

  8. How might a hole in the heart wall between the two ventricles affect the circulation of
    blood?

  9. To what organ or organs does the coronary circulation bring blood?

  10. To what organ or organs does the pulmonary circulation bring blood?

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