Explore how platelet and damaged-tissue factors trigger a clotting cascade, convert fibrinogen to fibrin and seal wounds against blood loss and infection in IB Biology SL C3.2.3.
People with the inherited disease hemophilia have a deficiency in one of the proteins that act as clotting factors in blood.
Explain how blood clotting occurs and the consequence for a person who has hemophilia.
Clotting process:
Blood clotting seals cuts in the skin.
Clotting factors are released from platelets.
Thrombin is activated.
A cascade reaction occurs with thrombin.
Thrombin causes fibrinogen to be converted to fibrin.
Fibrin forms a clot/blocks the cut/prevents blood from being lost.
Consequences of hemophilia:
If a person does not have enough clotting factors/has hemophilia, the clot will not form.
Pathogens can enter the body more easily.
Blood will be lost from a cut, affecting blood pressure / causing bleeding to death.
Loss of blood affects the amount of hemoglobin/O2 carried around the body.
Reference to lifestyle / menstrual/birth problems, e.g. surgery or contact sports.