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Human Blood Circulatory system

 1. Definition

The blood circulatory system is a network of the heart, blood, and blood vessels that transports nutrients, gases, hormones, and waste products throughout the body.

2. Main Components

  1. Heart – the muscular pump.
  2. Blood – the fluid that carries oxygen, nutrients, hormones, and waste.
  3. Blood Vessels – the channels for blood flow:
    • Arteries – carry blood away from the heart (usually oxygen-rich).
    • Veins – carry blood toward the heart (usually oxygen-poor).
    • Capillaries – tiny vessels where exchange of substances occurs between blood and tissues.

3. Circulation Types

  1. Pulmonary circulation – blood flow between heart and lungs:

    • Right side of the heart pumps deoxygenated blood to the lungs.
    • Blood picks up oxygen and returns to the left side of the heart.

  2. Systemic circulation – blood flow between heart and the rest of the body:

    • Left side of the heart pumps oxygenated blood to all body tissues.
    • Blood returns deoxygenated to the right side of the heart.

4. Heart Anatomy (FSc level)

  • Chambers: 4 (Right Atrium, Right Ventricle, Left Atrium, Left Ventricle)
  • Valves: Prevent backflow
    • Tricuspid – between right atrium & ventricle
    • Bicuspid / Mitral – between left atrium & ventricle
    • Pulmonary valve – right ventricle → lungs
    • Aortic valve – left ventricle → body
  • Major vessels:
    • Aorta – carries oxygen-rich blood to body
    • Pulmonary arteries – carry deoxygenated blood to lungs
    • Pulmonary veins – carry oxygen-rich blood to heart
    • Vena cava – superior & inferior, bring deoxygenated blood to heart

5. Blood Flow Summary

Body → Right atrium → Right ventricle → Lungs → Left atrium → Left ventricle → Body

If you want, I can draw a simple FSc-level diagram of the human circulatory system showing the heart, vessels, and flow — it really helps for remembering!

Do you want me to make that diagram?

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