1. The Blood How many litres of blood do you have in your body?
Blood has four main components
Plasma
Red blood cells
White blood cells
Platelets

3. 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

4. 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

5. Sickle Cell Anemia

6. 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

7. Platelets (1%) Help with blood clotting Release clotting factors
Scab forms

8. Blood Type

9. Blood Vessels
Arteries
Capillaries
Veins

10. Arteries: Capillaries: Veins:
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