Blood GCSE standard

1. Blood
Wednesday, 11 June 2014
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2. Red blood cells
• Carry oxygen from lungs to body tissue.
• There are 5 000 000 in 1mm3 of blood.
• They are adapted in the following ways:
(1) Size – thick diameter but thin width. They
just fit through a capillary but the surface to
volume ratio is large so they can absorb a lot
of oxygen.
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4. Red blood cells
(2) Shape – they are concave discs – this give
greater surface area.
(3) No nucleus – leaves more room for
haemoglobin – also no mitochondria or
ribosomes.
(4) Haemoglobin – this is a protein that carries
oxygen becoming oxyhaemoglobin.
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6. Haemoglobin
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7. Oxyhaemoglobin
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8. White blood cells
• Defend against diseases.
• They ingest bacteria and viruses.
• They produce antibodies.
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9. Human blood under microscope
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10. Platelets
• Platelets are small cells that allow blood to
clot.
• This stops bleeding and prevent bacteria from
entering the body.
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11. Plasma
• This is the straw coloured liquid in the blood.
• Over 90% of plasma is water.
• This dissolves:
(1) food – amino acids and glucose
(2) cholesterol – from the liver
(3) hormones – from glands
(4) antibodies
(5) water – to kidneys
(6) waste products like carbon dioxide and lactic
acid
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12. Plasma
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