HEMOSTASIS
,• It is the prevention of blood loss
• Whenever a blood vessel is severed or ruptured , following
mechanisms takes place to arrest the bleeding
1) Vascular spasm
2) Platelet plug formation.
3) Blood coagulation
4) Growth of fibrous tissue into the blood clot to close the hole
of the vessel
,HEMOSTASIS:
BV Injury
Tissue
Neural Factor
Blood Vessel Platelet Coagulation
Constriction Activation Activation
Primary hemostatic
plug
Reduced
Plt-Fusion Thromibn
Blood ,
flow
Fibrin
Stable Hemostatic Plug
, 1) VASCULAR SPASM:
• Trauma to the blood vessel causes the smooth muscles in the
vascular wall to contracts.
• Constriction reduces the blood flow from the injured vessel
• Vascular constriction results from
a) Local myogenic mechanism
b) Factors released from the traumatized vessel & platelets.
c) Nervous reflexes.
• Constriction lasts for many minutes to hours by which time
the process of platelet plug & blood coagulation takes place.
,• It is the prevention of blood loss
• Whenever a blood vessel is severed or ruptured , following
mechanisms takes place to arrest the bleeding
1) Vascular spasm
2) Platelet plug formation.
3) Blood coagulation
4) Growth of fibrous tissue into the blood clot to close the hole
of the vessel
,HEMOSTASIS:
BV Injury
Tissue
Neural Factor
Blood Vessel Platelet Coagulation
Constriction Activation Activation
Primary hemostatic
plug
Reduced
Plt-Fusion Thromibn
Blood ,
flow
Fibrin
Stable Hemostatic Plug
, 1) VASCULAR SPASM:
• Trauma to the blood vessel causes the smooth muscles in the
vascular wall to contracts.
• Constriction reduces the blood flow from the injured vessel
• Vascular constriction results from
a) Local myogenic mechanism
b) Factors released from the traumatized vessel & platelets.
c) Nervous reflexes.
• Constriction lasts for many minutes to hours by which time
the process of platelet plug & blood coagulation takes place.
