Bleeding & Thrombosis Flashcards
Describe the clotting process
Good luck bro
Vessel damage exposes collagen and releases Physiological activator
Platelets adhere to the site of damage
A platelet homeostatic plug forms
Fibrin forms on the clot
Natural anticoagulants keep the clot in the same place
Fibrinolysis breaks the clot down over time
What activator is subsequently released by Physiological activator after vessel damage?
Tissue activator
After vessel damage occurs, why do platelets adhere to the site of injury?
As collagen is exposed which is sticky
What are the 3 components of clot formation?
Coagulation factors
Platelets
Von Willebrand Factor (VWF)
I’m the dotting process, what ensures that the clot stays in the correct place?
Natural anticoagulants
What agents eventually break down the fibrin clot?
Fibrinolytic
In a normal blood vessel, are clotting factors present?
Yes, but they’re inactive bro
What 2 things prevents things from sticking to the endothelium of normal blood vessels?
Prostaglandins
Nitrous oxide
What cells to platelets differentiate from?
Megakaryocytes
Which differentiate from common myeloid progenitors
What 2 things are present on the surface of platelets?
Receptors
Glycoproteins
What is the function of the glycoproteins that are present on the surface of platelets?
Allow the platelet to bind once a receptor is activated
What are the 3 different types of receptors found on platelets?
Thrombin receptor
ADP receptor
Adrenaline receptor
What is contained within platelets?
Granules
What are the 3 functions of a platelets?
AAA
Adhering
Activating
Aggregating
What allows platelets to carry out their adhering function?
Glycoproteins
What allows platelets to carry out their activating function?
ADP
Adrenaline
Cycloxygenase (COX)
What allows platelets to carry out their aggregating function?
Arachidonic acid
Scramblase
They both make the platelets extra sticky so platelets can adhere to them
What forms arachidonic acid, which is responsible for platelet aggregation, and what is the catalyst?
ADP and adrenaline
Catalysed by Cycloxygenase (COX)
What regulates the production of platelets?
Thrombopoietein
Thrombopoietein regulates the production of platelets, which organ produces it?
The liver
What factor number does Von Willebrand factor (VWF) have a receptor for?
8
What factor deficiency is the most common bleeding disorder?
VWF
What are the 6 steps of the coagulation pathway?
- Tissue factor binds to F7
- F7 is activated, forming F7a
- F7a binds to F10
- F10 is activated, forming F10a
- F10a coverages prothrombin into thrombin
- Thrombin converts fibrinogen into fibrin
What 5 factors are involved in the coagulation pathway?
Tissue factor
F7 and F7a
F10 and F10a
In the clotting pathway, what factor converters prothrombin into thrombin?
F10a
If natural anticoagulants are absent, what is the patient at an increased risk of?
VTE (PE and DVT)
As blood clots to easily bro and can break off and fly awayyyy
What are the 3 main examples of natural anticoagulants?
Tissue Factor Pathway Inhibitor (TFPI)
Proteins C and S
Anti-thrombin
What 2 factors does the natural anticoagulant Tissue Factor Pathway Inhibitor (TFPI) bind to?
F7
F10a
What 2 factors does the natural anticoagulants Proteins C and S bind to?
F5
F8
What 2 factors does the natural anticoagulant Anti-thrombin bind to?
F10a
Thrombin
What type of bleeding involves mucous membranes?
Platelet type
What are the 2 main types of bleeding?
Platelet type
Clotting factor type
What type of bleeding involves deep haematomas?
Clotting factor type
What type of bleeding involves petechial rashes?
Platelet type
What are some of the causes of platelet type bleeding?
Von Willebrands disease
Immune thrombocytopenic purpura (ITP)
Haemolytic uremic syndrome
Thrombocytopenia
What is a cause of clotting factor type bleeding?
Haemophilia
When taking a history, what questions do you need to ask about regarding bleeding?
History of bleeding
Severity
Bleeding pattern
Previous surgeries
What coagulation factors are dependent on Vit. K?
2, 7, 9 and 10
Apart from it’s adhering, aggregating and activating (3 As) functions, what other function does platelets have?
Maintains vascular integrity
Do platelets have a role in maintaining vascular integrity
Yeah
