WebzmedlecturesWMLDISORDERS AFFECTING HEMOSTASIS

DEFINITION

HOW DOES THE BODY REPSOND TO THIS?

ANSWER

TECHNICALLY

• WHAT IS HEMOSTASIS: It is a complex physiological respond of the body to insult brought about by bleeding,based on the interaction of :

• Plasma factors

• Thrombocytes or platelets

• Blood vessel.

STAGES OF HEMOSTASIS

CLOTH DISSOLUTION

VESSEL SPASM

HOW DOES IT HAPPEN (SPASM OF VESSELS)

• 1. The endothelial cells send information to the smooth muscle cell and this causes their contraction.

• Information is related to the smooth to the nerve innervation of the smooth muscle

PLATELET PLUG FORMATION

ORIGINATE FROM MEGAKARYOCYTES

STEPS IN PLUG FORMATION

• PLATELETS ACTIVATION

• ADHESION OF LATELETS

• AGGREGATION OF PLATELETS.

PLATELET ACTIVATION

• Factors that activate platelets are release from their cytoplasm, and they include

• 1.ADP

• 2.Serotonin

• 3.PDGF, (platelet derived growth factor)

• Platelet factor 4

WHAT HAPPEN WHEN THEY ARE ACTIVATED?

• When platelets are activated they change their shape from a disc shape to a spherical shape

• This change of shape helps them to obtain the ability to adhere and aggregate.

ADHESION

AGGREGATION

We get the platelet plug or the primary hemostatic plug.

COAGULATION CASCADE

• Main purpose is to stabilize and strengthens the platelet plug

• To form the fibrin mesh that give that stability required.

Definition

• Coagulation cascade is a complex biological process that leads to the conversion of soluble plasma fibrinogen to fibrin.

• 3 main stages

• -formation of thromboplastine comlex

• -transformation of prothrombin to

Thrombin

.-transformation of fibrinogen to fibrin

Factors INVOLVED

THEIR INTERACTIONS

LIMITATION OF COAGULATION

• It is a good thing that this process is restricted to the particular region involve in the insult,this is achieved by inhibitors of activated coagulation factors, and fibrinolysis

FIBRINOLYTIC SYSTEM

• This process leads to the restoration of vessel potency, that is the continuity of the vessel.

HOW IT HAPPENS !!