HEMA 2 - LESSON 1: Introduction to Hemostasis

A physiologic process that stops the flow of blood

Hemostasis

Disorder when the body does not know how to maintain blood in its liquid state

Thrombotic disorder

Disorder when the body lacks necessary components to produce and form a clot leading to uncontrolled bleeding

Hemorrhagic disorder

Disorder when the body is not ready to produce a clot and leads to another bleeding

Fibrinolytic disorder

NORMAL state of blood INSIDE the blood vessels

Fluid

ABNORMAL state of blood INSIDE the blood vessels

Coagulation (Thrombosis disease)

NORMAL state of blood OUTSIDE the blood vessels

Coagulation (Hemostasis)

ABNORMAL state of blood OUTSIDE the blood vessels

Fluid (Hemorrhagic disease)

Enumerate the Cellular components of Hemostasis

1. Platelets
2. Vascular intima cells
3. Extravascular tissue factor-bearing cells

Enumerate the Extravascular tissue factor-bearing cells

1. Fibroblasts
2. Smooth muscle cells
3. Endothelial cells

Enumerate the Plasma components of Hemostasis

1. Coagulation proteins
2. Fibrinolytic proteins
3. Inhibitors

Function of Coagulation proteins

Allows clot formation

Function of Fibrinolytic proteins

Balancer that helps dissolve the clot

Function of Inhibitiors (Hemostasis)

Regulators for needed processes

Type of cell: Innermost Vascular Lining of Vascular intima

Endothelial cells

Type of cell: Support Endothelial cells

Internal elastic lamina (Elastin and Collagen)

Type of cell: Subendothelial Connective Tissue of Vascular intima - VEINS

• Collagen

• Fibroblasts

Type of cell: Subendothelial Connective Tissue of Vascular intima - ARTERIES

• Collagen

• Fibroblasts

• Smooth muscles

The first and immediate response to vascular injury that is rapid and short-lived by producing a platelet plug

Primary Hemostasis

Why is Primary Hemostasis short-lived?

Replaced by Secondary hemostasis with a more stable fibrin clot

What process produces a platelet plug?

Platelet aggregation

End product of Primary Hemostasis

Platelet plug

Enumerate the diseases affecting Primary Hemostasis

1. Collagen abnormalities leading to poor platelet response
2. Thrombocytopenia
3. Qualitative platelet disorders
4. Von Willebrand Disease (vWD)

What disease is a blood disorder wherein blood does not clot properly due to the absence of the binding site of platelets?

Von Willebrand disease (vWD)

The second, long-term response to large injuries that activates coagulation proteins to form fibrin clots

Secondary Hemostasis

Enumerate the components of Secondary Hemostasis

1. Coagulation factors
2. Coagulation inhibitors

What is the enzyme that activates coagulation in Secondary Hemostasis?

Zymogens

Precursor for thrombin

Prothrombin

Enzyme that converts FIBRINOGEN to FIBRIN CLOT

Thrombin

What factor stabilizes Fibrin?

• Factor 13

• Factor XIII

• Fibrin stabilizing factor

End product of Secondary Hemostasis

Fibrin clot

The breakdown of clots and is the final stage of coagulation

Fibrinolysis

What is the natural breakdown of clots?

Primary Fibrinolysis

What is the breakdown of clots due to medical disorders or medicines?

Secondary Fibrinolysis

Product of Plasminogen + TPA & UPA

Plasmin

Function of Plasmin

Dissolves fibrin clot

Product of Fibrin + Plasmin

Fibrin Degradation Product

End product of Fibrinolysis

Fibrin Degradation Product

Converts plasminogen to plasmin

• TPA

• UPA

Enumerate the inhibitors of Fibrinolysis

1. PAI-1
2. A2-AP
3. TAFI

What does Plasminogen Activator Inhibitor-1 (PAI-1) inhibit?

TPA

What does Alpha 2-Antiplasmin (A2-AP) inhibit?

Plasmin

What does Thrombin-Activatable Fibrinolysis Inhibitor (TAFI) inhibit?

Fibrin binding sites