The Blood

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The Blood

• How many litres of blood do you have in your
  body?
• 4-6 L
• Blood has four main components
• Plasma
• Red blood cells
• White blood cells
• Platelets

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Plasma (55)

• Straw coloured solution containing
• Water with dissolved salts (90)
• Plasma proteins (10)
• Nutrients, metabolic wastes, hormones, O2, CO2
• Plasma proteins help transport vitamins and fight
  viral and bacterial infections

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Red Blood Cells (41)

• Carry oxygen (hemoglobin)
• Produced in bone marrow (2 million/second)
• No nuclei
• Life span of 100 days
• Gives them a flat disk shape
• Increased surface area for O2 molecules
• Flexibility to squeeze through different sized
  blood vessels

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Sickle Cell Anemia
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White Blood Cells (3)

• Fight infection, parasites, and bacteria
• Can move through blood vessel walls
• Your WBC count increases when you have an
  infection
• Pus is WBCs and dead bacteria
• Produced in the bone marrow
• Life span of years

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Platelets (1)

• Help with blood clotting
• Release clotting factors
• Scab forms

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Blood Type
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Blood Vessels

• Arteries
• Capillaries
• Veins

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• Arteries
• Carry blood away from the heart to the body
  tissues
• Smaller diameter
• High pressure
• Capillaries
• Exchange of nutrients and wastes (diffusion
  gradient)
• Tiny tubes with large surface area
• Veins
• Carry blood back to the heart
• Larger diameter
• Low pressure
• Valves allow blood to only flow in one direction

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