Blood
Blood is a tissue : a liquid, plasma , with red blood
cells , white blood cells and platelets suspended in it
Component
Function
Adaptation
Plasma transports dissolved substances: carbon dioxide, glucose, urea, hormones, proteins
liquid, so it flows and dissolves substances
Red blood cells carry oxygen from the lungs to the cells
contain haemoglobin which binds oxygen; no nucleus so more room for haemoglobin; biconcave disc shape for a large surface area
White blood cells defend against pathogens
some engulf pathogens (phagocytosis); some make antibodies or antitoxins; have a nucleus
Platelets clot the blood at a woundfragments of cells; no nucleus
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Blood under the microscope red blood cell biconcave disc — a big surface area for its volume, and no nucleus, so there is more room for haemoglobin, which carries the oxygen white blood cell much bigger, and it HAS a nucleus (often lobed) some engulf pathogens, others make antibodies platelets small fragments of cells that make the blood clot plasma the straw-coloured liquid the rest is carried in — it transports carbon dioxide, urea, hormones, digested food and heat Blood is a tissue: four components with one job between them. Anything the body needs to move from one place to another travels in it. A blood smear as seen under a microscope: many biconcave red blood cells, a larger white blood cell with a lobed nucleus, and small platelet fragments, each labelled
Blood products (transfusions, plasma, platelets) save lives but carry risks
of infection transfer and reactions, so donations are screened
If red blood cells are destroyed, less oxygen is carried, so less
respiration , so less energy released and the person is tired.
Take the chain all the way to respiration; and it is "less", not "no"
oxygen
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In the full topic
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