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.

As the platelet plug forms it activates the coagulation cascade which uses fibrin deposits to form the clot. A “white clot” is made up mostly of platelets, while a “red clot” is made up of mostly fibrin. Typically our clots are a mixture of both

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