VASCULAR SYSTEM Flashcards
What are the three layers of blood
vessel?
Vascular intima (inner layer)
Vascular media (middle layer)
Vascular adventitia (outer layer)
provides interface between circulating blood throughout the body
Vascular intima (inner layer)
its endothelial surface is usually inert to platelets and coagulation (termed as non-thrombogenic surface
Vascular Intima
● if the lining is disrupted, the injured vessel and its adjacent
vessel constricts (vasoconstriction)
● the innermost lining of blood vessels is a monolayer of
metabolically active endothelial cells (ECs)
Vascular Intima
-Platelet inhibitor
-Vasodilator
-Synthesized through the eicosanoid pathway
Prostacyclin (PGI2)
-Induces smooth muscle relaxation (vasodilation)
-Inhibits platelet activation
-Promotes angiogenesis
-Synthesized in ECs, vascular smooth muscle
cells, neutrophils, and macrophages
Nitric Oxide
Controls activation of the Tissue factor pathway .Limits the activation of the TF:VIIa:Xa complex
Tissue Factor Pathway Inhibitor
Facilitated by the endothelial
protein C receptor (EPCR). Serves as a cofactor in protein C activation when bound to thrombin
Thrombomodulin
A glycosaminoglycan that enhances the
activity of antithrombin
Heparan sulfate
Induced by a harmful local stimulus (mechanical or chemical)
Vasoconstriction
● Produced by fibroblasts
● Binds and activates platelets
Collagen
Secreted by endothelial cells from its storage site called ?
Weibel-Palade bodies
-Primarily binds to platelet membrane receptor GPIb to promote adhesion
-Functions as a carrier to factor VIII
von Willebrand factor
Secreted from ECs. Serves an important function as it cleaves large vWF multimers into shorter chains that support normal platelet
adhesion
ADAMTS-13
● Secreted by ECs
● Coats ECs
● An adhesion molecule that promotes platelet and leukocyte-binding
P-selectin
● Secreted by ECs
● Are immunoglobulin-like adhesion molecules
● Further promotes platelet and leukocyte binding
Intercellular cell adhesion molecules
(ICAMs) and Platelet endothelial cell
adhesion molecules (PECAMs)
● Supports the constitutive membrane protein tissue factor
● Disrupted ECs exposes TF in subendothelial cells (activates the coagulation system through contact with factor VII)
Smooth muscle cells and fibroblasts
White Clot
-Consists of platelet and vWF
-In arteries and arterioles
Bulky Red Clot
-Consists of platelets, vWF,
fibrin, and red blood cells
-In veins
● During thrombus formation, both TPA and plasminogen
bind to polymerized fibrin
● Activates fibrinolysis by converting plasminogen to plasmin
Tissue Plasminogen Activator
● A TPA control protein that inhibits plasmin generation and fibrinolysis
● Can slow fibrinolysis
● Increases the tendency for thrombosis
Plasminogen Activator Inhibitor-1
● Is activated by thrombin bound to EC membrane thrombomodulin
● Can slow fibrinolysis
● Increases the tendency for thrombosis
Thrombin Activatable Fibrinolysis
Inhibitor
