HEMOSTASIS
PREPARED BY PUNAM SAHOO
,Hemostasis
• Hemostasis is defined as arrest or stoppage of bleeding.
Stages of Hemostasis
• When a blood vessel is injured, the injury initiates a series of
reactions, resulting in hemostasis.
• It occurs in three stages.
Vasoconstriction
Platelet plug formation
Coagulation of blood
, Vasoconstriction
• Immediately after injury, the blood vessel constricts and
decreases the loss of blood from the damages portion.
• When the blood vessels are cut, the endothelium is
damaged and the collagen is exposed.
• Platelets adhere to this collagen and get activated.
• The activated platelets secrete serotonin and other
vasoconstrictor substances which cause constriction of
the blood vessels.
• Adherence of the platelets to the collagen is accelerated
by Von Willebrand factor. This factor acts as a bridge
between a specific glycoprotein present on the surface of
platelet and collagen fibrils.
PREPARED BY PUNAM SAHOO
,Hemostasis
• Hemostasis is defined as arrest or stoppage of bleeding.
Stages of Hemostasis
• When a blood vessel is injured, the injury initiates a series of
reactions, resulting in hemostasis.
• It occurs in three stages.
Vasoconstriction
Platelet plug formation
Coagulation of blood
, Vasoconstriction
• Immediately after injury, the blood vessel constricts and
decreases the loss of blood from the damages portion.
• When the blood vessels are cut, the endothelium is
damaged and the collagen is exposed.
• Platelets adhere to this collagen and get activated.
• The activated platelets secrete serotonin and other
vasoconstrictor substances which cause constriction of
the blood vessels.
• Adherence of the platelets to the collagen is accelerated
by Von Willebrand factor. This factor acts as a bridge
between a specific glycoprotein present on the surface of
platelet and collagen fibrils.
