The document discusses blood clotting and the factors involved. Platelets and clotting factors work together to form blood clots which act as a mesh to stop bleeding from injuries. When a blood vessel is damaged, platelets stick to the injury site and clump together to form a platelet plug. Platelets and damaged tissue then release clotting factors which activate the blood clotting mechanism and produce fibrin to seal the wound. Impaired clotting can lead to excessive bleeding or blockages in arteries from blood clots.

1. Blood Clotting

2. Blood cells involved
Platelets
+
Clotting factors

3. Blood Clotting Factors
Factor
Number
Common Name
I
II
III
IV
Va
VII
VIII
IX
X
XI
XII
XIII
Fibrinogen
Prothrombin
Tissue Factor
Ca2+
Proaccelerin
Proconvertin
Antihemophilic Factor
Christmas Factor
Stuart Factor
Plasma thromboplastin antecedent
Hageman factor
Fibrin Stabilizing Factor

4. Process
• Injury/ rupture to blood vessel
• Blood vessel around wound constrict
- reduce blood flow to the damaged
area.
• Activated Platelets stick to injury site
• Platelets become sticky and clump together
to form platelet plug.
• Platelets & damaged tissue release clotting
factors (eg.Factor VIII)
• Blood clotting mechanism to form Fibrin
which acts like a mesh to stop the bleeding.

5. Platelet activation also induces
large morphological changes
unactivated
fully activated

6. Blood Clotting Mechanism

9. Scab Formation

10. Blood Clotting Videos
• Blood Clotting Video 1
• Blood Clotting Video 2

15. Necessity For Blood Clotting
• Prevent excessive blood loss
• Prevent entry of micoorganisms
through wound. Seals wound.
• Maintain blood pressure

16. Consequences of Impaired Blood
Clotting
• No Factor VIII – Haemophilia
– Blood clots slowly

17. Consequences of Impaired Blood Clotting
• Blood clot (Thrombus) blocks
artery (Thrombosis)
• Thrombus dislodged &
carried in blood flow (Embolus)
• Embolus trapped in small
artery & blocks blood
flow (Embolism)

18. Consequences of Impaired Blood Clotting
• Coronary artery partially blocked – chest pains
(angina)
If totally blocked – heart attack – death
• Blockage of blood to brain cells – Stroke

19. Thrombosis & Embolism Video

20. Assignment - Flow Chart

21. EXTRA