http://www.youtube.com/watch?v=036GFPRH5-w

CHAPTER 11.3 Understanding the Mechanism of Blood Clotting

13 January 2011 2:45 pm to 3:30

Learning Outcomes:At the end of this class you must be able to

explain the necessity for blood clotting at the site of damage vessels

explain the mechanism of blood clottingpredict the consequences of impaired blood clotting in an individual

Necessity for Blood Clotting

Avoid excessive blood loss when a person is injured Maintains the circulation of blood in a close circulatory system Maintains blood pressure Prevents the entry of foreign substances, such as microorganism into the body through the wound.

Blood Clotting MechanismA cut in a blood vessel Blood flow out and vessel constricts Platelets on exposure to air, break down and release chemicals to cause other platelets to stick to each other

Platelets release clotting factor

Platelets clump together to form a plug to prevent blood loss

Blood Clotting MechanismInjury in blood vessels Platelet clump at the wound Platelets releases ThrombokinaseIn the present of factor VIII convert Formed in the liver requires vitamin K and Ca

Thrombinconvert

Prothrombin

FibrinogenSoluble plasma protein

FibrinInsoluble fibres protein

Mesh network Scab Blood Clot

Consequences of Impaired Blood Clotting Mechanismhaemophilia* Lack of gene for production of clotting factor (vitamin K) * An impaired clotting mechanism which causes serious bleeding

Thrombosis Embolism* A local blood clot (thrombus} is formed on the damage rough inner wall of the artery. (thrombosis) * Blockage of the artery * Thrombus dislodge and is carried away by blood circulation (embolus) * Embolus trapped and block the blood flow

Heart attack

C A U S E S

* The coronary artery is partially blocked , it cause angina (chest pain) * Total blockage : cuts off the supply of oxygen and nutrients to the heart muscle causes heart attack * Extensive heart muscle damage can cause death

O V E R C O M E

* Factor VII can now be produced by generic engineering

* Avoid to take foods rich in fats Consume more fruits and vegetables * Exercise and practice a healthy lifestyle

Terms in Blood ClottingFibrinogen, Factor I - A protein present in blood plasma; converts to fibrin when blood clots Prothrombin, Factor II - A protein in blood plasma that is the inactive precursor of thrombin Thromboplastin, Thrombokinase, Factor III - An enzyme liberated from blood platelets that converts prothrombin into thrombin as blood starts to clot Calcium ion, Factor IV - Ion of calcium; a factor in the clotting of blood Proaccelerin, Prothrombin accelerator, Accelerator factor, Factor V - A coagulation factor Proconvertin, Cothromboplastin, Stable factor, Factor VII - A coagulation factor formed in the kidney under the influence of vitamin K Antihemophilic factor, Antihaemophilic factor, Antihemophilic globulin, Antihaemophilic globulin,Factor VIII, Hemofil - A coagulation factor (trade name Hemofil) whose absence is associated with hemophilia A Christmas factor, Factor IX - Coagulation factor whose absence is associated with hemophilia B Prothrombinase, Factor X - Coagulation factor that is converted to an enzyme that converts prothrombin to thrombin in a reaction that depends on calcium ions and other coagulation factors Plasma thromboplastin antecedent, Factor XI - Coagulation factor whose deficiency results in a hemorrhagic tendency Hageman factor, Factor XII - Coagulation factor whose deficiency results in prolongation of clotting time of venous blood Fibrinase, Factor XIII - In the clotting of blood thrombin catalyzes factor XIII into its active form (fibrinase) which causes fibrin to form a stable clot

Activity 1 : 5 minutes conversation Let talk about blood clotting

Situation:

Hidayahs finger bleeding because off paper cut. She is panic and worry. Darren tell Hidayah to calm down.Darren : Dont worry your blood will clot immediately. Hidayah : clot? What do you mean my blood will clot? Darren : .. Hidayah : How it can be happened

Key words : Atika : thrombokinase, Raihan : Fibrin, Raihanah : vitamin K, Darren :,calcium

ExerciseAnswer the following questions: 1. What is the function of thrombokinase?

____________________________________________2. ____________soluble plasma protein converts into ____________insoluble fibrin fibres by the _____________ 3. Prothrombin formed in the ____________ , it formation requires ______________ and _____________ 4. What happen to the platelets when it expose to air. ____________________________________________________ 5.Differentiate between thrombosis and embolism ____________________________________________________ 6. Differentiate between angina and heart attack __________________________________________________

homework

Draw mind map to summarize the necessity for blood clotting Draw a diagram/flow chart to show mechanism of blood clotting Draw a table to compare and contrast circulatory system of insect, fish, amphibians and humans