Circulation: Physiological thrombosis & clotting in wound healing Flashcards
What is the structure of an arteriole
Endothelial cells line lumen
Smooth muscles surround basal lamina (basement membrane)
Interstitial collagen fibres surround smooth muscle
What is contained in the lumen of arterioles
RBCs
WBCs
Platelets
Plasma
What is contained in the plasma
Clotting factors
What is the clotting cascade
Amplification system
Results in thrombin production from prothrombin
Thrombin converts soluble fibrinogen->insoluble fibrin
Fibrin forms mesh of strands
In what way does initial damage initiate clotting
Leads to
1. Exposure of interstitial collagen
2. Exposure of Tissue factors
How can trauma lead to clotting cascade
Trauma leads to vessel defect
Blood leaks out
Plasma clotting factors contact collagens which become activated
Tissue factor from smooth muscle binds to clotting factor
Causes clotting cascade
What substance does the clotting cascade produce
Thrombin from prothrombin
What is the function of megakaryocytes?
produces platelets in bone marrow
How do platelets work
Trauma-> platelets exposed to collagen
Platelets adhere together to close gap
What are the two types of coagulation
Thrombus formation
Clot formation
Where does thrombus formation occur
In flowing blood
What does thrombus formation consist of
Platelets
Mesh network of fibrin
Where does clot formation occur
Stagnant blood
What does a clot consist of
Fibrin network
RBC
What is the process of haemostasis
Trauma to skin
Vasoconstriction
Clot formation
Thrombus formation
Produces granulation tissue
