• Irregular shape • Colourless • Sticky • Very very tiny!

• Maintain homeostasis by preventing blood loss

• 1. Adhesion: platelets attach to the rip or tear in the blood vessel

• 2. Activation: platelets change shape, turn on receptors and secrete chemical messages to other cells • “coagulation cascade”

• Coagulation cascade = combination of proteins activated by the chemical messages from the platelets. At the end of the coagulation cascade fibrinogens have become fibrin.

• Fibrin = product of fibrinogens which are blood clotting proteins

• 3. Aggregation: platelets continue to collect along with fibrin and develop into the platelet plug.

• What would be an example of a good blood clot?

• A bad one? • What might be the results of a bad blood

clot?

• Can be caused by: • Cancer, pregnancy, lupus, rheumatoid arthritis, certain medications• Damage to the inside of blood vessels

• Can lead to: • Heart attack, stroke, embolism

• Smoking• Physical inactivity

Treatments

• https://www.youtube.com/watch?v=--bZUeb83uU