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The Heart

The heart pumps blood around the body. The heart's work ensures that cells have the oxygen needed for respiration.

The heart

The heart

  • The heart is a muscle.
    • The heart pumps the newly oxygenated blood around the body.
    • The heart pumps deoxygenated blood back to the lungs.
  • Humans have one heart that is around the size of a person's fist.
    • The heart is located in the middle left of your chest.
Unusual animal hearts

Unusual animal hearts

  • Cuttlefish and octopuses have three hearts.
    • These creatures have so many hearts to ensure that blood is pumped around their complex bodies.
  • Earthworms do not have hearts.
Four chambers of the human heart

Four chambers of the human heart

  • Left atrium
    • Where oxygenated blood comes from the lungs.
  • Left ventricle
    • Pumps oxygenated blood around the body.
  • Right atrium
    • Where the deoxygenated blood enters the heart from body.
  • Right ventricle
    • Pumps deoxygenated blood to the lungs.

The Blood

The blood delivers oxygen and removes carbon dioxide as it moves around the body. Blood is contains plasma, platelets, red blood cells, and white blood cells.

Blood plasma

Blood plasma

  • Blood plasma
    • Plasma is the straw-coloured liquid component of blood.
  • Plasma contains a variety of substances including:
    • Suspended nutrients
    • Antibodies
    • Proteins
    • Hormones
    • Urea
    • Blood cells
Blood platelets

Blood platelets

  • Blood platelets are found in the blood plasma.
    • Platelets are used in blood clotting.
Red blood cells

Red blood cells

  • Red blood cells are also called erythrocytes.
    • Red blood cells are made in the bone marrow.
    • Red blood cells contain a protein called haemoglobin which carries oxygen around the body.
  • Red blood cells have a biconcave disc shape and a nucleus.
    • This shape increases surface area to maxmise oxygen absorption.
    • Red blood cells are very thin to make diffusion more efficient.
White blood cells

White blood cells

  • White blood cells are part of the body's immune system.
  • White blood cells engulf and destroy microorganisms that invade the body.
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Biology

1.1

Cells, Tissues & Organs

1.2

Reproduction & Variation

1.3

Ecological Relationships & Classification

1.4

Digestion & Nutrition

1.5

Plants & Photosynthesis

1.6

Biological Systems & Processes

2

Chemistry

2.1

Particles

2.2

Chemical Reactions

2.3

Atoms, Elements, Compounds

2.4

The Periodic Table

2.5

Materials & the Earth

2.6

Reactivity

2.7

Energetics

2.8

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3

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3.2

Forces & Motion

3.3

Waves

3.4

Electricity & Magnetism

3.5

Matter

3.6

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4

Disciplinary Knowledge

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