Vascular disorders I Flashcards
What is DIC/ Disseminated
intravascular
coagulopathy (DIC) ?
Condition that causes abnormal clotting throughout the body
What is the consequence of haemostasis being blunted/ lost?
Excessive Bleeding
What is an example of an operation that could cause excessive bleeding?
Ligatures moving during a spay
What is primary haemostasis?
Platelets seal the vascular defect and they are then activated
What are the 4 steps involved in haemostasis?
- Arteriolar vasoconstriction
- Primary haemostasis
- Secondary haemostasis
- Clot stabilisation and resorption
Name the clotting factors that will kill the animal if altered by a genetic disease
7,10,5,8,2
What clotting factor will not effect the clotting cascade if altered as it can be bypassed?
11
What clotting factor will cause a decrease in coagulation if altered
12
What clotting factors are affected by vitamin K?
10, 7, 8, 2
What are three factors that affect coagulation?
- Dilution- coagulation factors are washed away via blood flow
- Negatively charged phospholipids- The factors aren’t activated
- Reaction of the adjacent endothelium as this activates the fibrinolytic cascade
What is the most important protein that reduces the size of the clot
Plasmin
What is plasminogen?
The potent activator of plasmin
What is thrombin?
The progenitor to fibrin
it has anticoagulant factors due to the secretion of plasminogen
What is the purpose of Fibrin?
Produces/ Makes the clot
What is the purpose of the fibrinolytic cascade?
It limits the size of the clot
How does the endothelium act as an anticoagulant?
It can make a barrier between the vWF and the platelets
What is an example of a primary Haemorrhagic disorder?
Von WilleBrand disease
What is an example of a secondary haemorrhagic disorder?
A deficiency in coagulation factors
How does scurvy cause bleeding?
Lack of Vitamin C
What animals is scurvy seen in?
It is seen in guinea-pigs and fresian horses
What three factors decide how bad a haemorrhagic disorder is?
- Volume (e.g how much blood is lost)
- Rate
- Location (e.g blood loss in brain vs spleen)
What kind of deficiency can chronic blood loss lead to?
Iron deficiency
(and anemia)
How big is a petechia haemorrhage?
2mm (seen in sepsis)
How big is a Ecchymosis haemorrhage?
2-3mm
How big is a Purpura haemorrhage?
4-10mm
What can a haemorrhage in the brain lead to?
Necrosis
Name three things that can cause Thrombosis
- Endothelial injury
- Stasis/ Turbulent blood flow
- Hypercoagulability of blood
What is the definition of haemostasis?
The prevention of blood loss,
How does consumption of coagulation factors lead to DIC?
Widespread activation of clotting factors due to DIC leads to an overall decrease in clotting factors (may lead to secondary fibrinolysis)
What is the link between negatively charged phospholipids and activation factors?
Negatively charged phospholipids create a surface that assists in the binding and activation of coagulation factors
What does t-PA facilitate?
The breaking down of blood clots
What are some factors that inhibit fibrinolysis?
Heparin like molecules (competition)
Thrombomodulin
Prostacyclin
Nitrous oxide
