Section 2(h) Transport (Human) - 2.64B - Blood Clotting

Front

What is the role of platelets?

Back

Platelets are fragments of cells that start the chemical process of blood clotting when a vessel is damaged.

Front

What happens when a blood vessel is cut?

Back

Platelets are exposed to the damaged edges and release clotting factors.

Front

How is fibrinogen converted to fibrin?

Back

Soluble fibrinogen, a plasma protein, is turned into insoluble fibrin threads.

Front

What does fibrin do in the clotting process?

Back

Fibrin forms a mesh across the wound that traps red blood cells and more platelets.

Front

What is the purpose of a scab?

Back

The clot hardens and dries to form a scab, protecting the wound while the skin repairs itself.

Front

Why is blood clotting important?

Back

Clotting prevents excessive blood loss and stops blood pressure from dropping.

Front

How does clotting prevent infection?

Back

The clot or scab acts as a physical barrier to block micro-organisms (pathogens) from entering.

Front

What role do calcium and Vitamin K play in clotting?

Back

They are essential co-factors for the chemical reactions that turn fibrinogen into fibrin.

Front

What triggers blood clotting?

Back

Clotting is triggered by chemicals released by damaged tissue and platelets.

Front

Why is fibrin insoluble?

Back

If fibrin were soluble, it would wash away in the blood instead of forming a plug.