Thrombosis Flashcards
What is thrombosis?
Formation of blood clot inside a blood vessel
What are the whites of your eyes made of?
Collagen
Blood vessel
Lumen, which contains RBCs, WBCs and platelets, plasma (water and plasma proteins/ molecules).
Collagen surrounds basal lamina which surrounds vessel.
Platelets cannot touch collagen
What is the difference between plasma and serum
Plasma contains clotting factors, serum is plasma without clotting factors.
Clotting factors
Liver produces loads of proteins Clotting factor produced by endothelial cells THROMBIN production FIBRIN produced is the clot Clotting cascade = amplification system.
Damage-> TF
Prothrombin -> thrombin
Fibrinogen -> fibrin
Initial damage
Trauma - exposure of interstitial collagens between structures
Exposes TISSUE FACTOR
TF
Tissue factor
Present on muscle cells
Damage = TF release onto interstitial collagens which attaches and initiates clotting cascade
Fibrinogen to fibrin
Soluble to insoluble
Fibrin meshwork that catches things.
Platelets
Produced in bone marrow
Bits of cells
Exposure to interstitial collagen
Only work in flowing blood - adhere to edges of blood vessels that have been damaged.
Megakaryocyte?
Big cell with lots of nuclei
Undergoes nuclear division but not cell division
What is coagulation?
Solidification of blood
2 types: thrombus formation, clot formation
Thrombus formation
Pure thrombus is pale cream colour
Consists of fibrin meshwork and platelets.
Occurs in flowing blood
Platelets and clotting cascade important
Clot formation
‘Black pudding’
Blood leaks out of a vessel, sit in tissues, next to interstitial collagen (as bruise)
Activation of clotting system - fibrin strands with RBCS.
NO platelets
Dark Red colour
Difference between thrombus and clotting
Thrombus - platelets, cream
Clotting - RBCs, red
What helps to stop bleeding?
Vasoconstriction
Decreases quantity and speed of blood - helps clotting
Can you get clotting and thrombus formation together?
Yes, leads to haemostasis
What is haemostasis?
Stopping bleeding
What is granulation tissue?
New vessels where there has been a wound
Main purpose - to oxygenate area and provide nutrients
Thrombosis is good if…
It allows blood flow along the vessel to continue
Thrombosis is bad if…
It blocks the vessel
What is ischaemia?
No blood getting into tissues, caused by vessel blockage by thrombosis
Results in HYPOXIA - lack of oxygen in tissues
What often comes alongside hypoxia
Ischaemia
What is stagnant blood behind a thrombus?
An unfortunate outcome of thrombus - causes clot behind
What is the fibrinolytic system?
Cuts up fibrin (getting rid of thrombus)
Plasma protein = plasminogen cuts up fibrin
OPPOSITE of clotting system
Thrombosis and clotting are normal in:
Wound healing
Stopping lending during menstruation
Some embryonic processes
Thrombosis & clotting abnormal in:
Vessels which have abnormal walls
Blood which has abnormal constituents (e.g smoking can cause abnormal, ‘sticky’ platelets)
Abnormal flow in vessel
What is Virchows triad?
Associated with abnormal thrombosis and clotting, 3 things
What diseases are viceroys triad associated with?
Coronary heart disease
Bowel disease
