Intrinsic Pathway Of Blood Coagulation

Intrinsic Pathway Of Blood Coagulation

Question 1. Name two bleeding disease how are they caused?
Answer:

Bleeding disease:

1. Hemophilia:

• It is a sex linked inherited diseases characterized by prolonged clotting time.

Hemophilia Causes:

• Hemophilia occurs due to lack of formation of prothrombin activator.
• Causes differs according to its type.

Hemophilia A:

• It is caused due to deficiency of factor VIII of coagulation.

Hemophilia B:

• It is caused due to deficiency of factor IX of coagulation.

2. Purpura:

• It is a bleeding disorder characterized by prolonged bleeding.
• Types and Its causes:

3. Von villebrand Disease:

• It is a bleeding disorder characterized by excessive bleeding even after a mild injury.

Von villebrand Disease Causes:

• It occurs due to deficiency of von wilebrand factor.
• This suppresses platelet adhesion.
• It also causes deficiency of factor VIII.

Question 2. Hemostasis:
Answer:

Hemostasis Definition:

• Arrest of bleeding is called hemostasis.

Hemostasis Stages:

1. Vasoconstriction:

• It includes the constriction of blood vessels to decrease the blood flow and prevent its loss.
• When blood vessel is cut, collagen gets exposed from the damaged endothelium of the vessel.
• The platets adhere to this collagen and gets activated and secrete contractile substances to cause vasoconstriction.
• This adherence of platelets is facilitated by von Willebrand factor and platelet activating factor.

2. Formation of Platelet plug:

• The platelet that are adhere to the exposed collagen secrete ADP and thromboxane A₂.
• These attract more and more platelets which aggregate to form and temporary loose platelet plug.
• This closes the vessel and prevents further blood loss.

3. Coagulation of blood:

• Fibrinogen gets converted into fibrin.
• This fibrin gets attached to the loosely formed platelet plug.
  This is then modified by fibrin stabilizing factor and calcium ions to form a meshwork.
• Thus, this is how blood loss in prevented after formation of blood clot.

Question 3. Describe intrinsic pathway of blood coagulation.
Answer:

Intrinsic mechanism of clotting: