Term
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Definition
The process of forming blood clots. A protective mechanism. |
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Term
What are the two hemostatic mechanisms? |
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Definition
-Primary hemostasis -Secondary hemostsis |
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Term
What does primary hemostasis deal with? |
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Definition
the vessel wall and thrombocytes |
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Term
What does secondary hemostasis deal with? |
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Definition
Coagulation factors that form fibrin |
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Term
Injury of the vessel wall results in what? |
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Definition
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Term
What does vasoconstriction do? |
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Definition
-Cuts down on blood flow temporarily -Stimulates release of factor III |
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Term
Where are thrombocytes produced? |
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Definition
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Term
When a cut is made in the skin, what do the thrombocytes do? |
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Definition
-adhere to subendothelial collagen of vessel wall -release bioactive substance (which stimulates extrinsic and intrinsic pathways -Aggregate forming plug -Stimulate secondary hemostasis |
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Term
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Definition
the "mother of thrombocytes" bits of broken off pieces form platelets |
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Term
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Definition
small purple dots on the skin (small bruising) |
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Term
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Definition
wide spread purple marks on the skin (larger bruising) |
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Term
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Definition
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Term
Are clotting factors categorized under primary or secondary hemostasis? |
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Definition
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Term
Where are the clotting factors produced? |
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Definition
Most are produced in the liver |
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Term
Are all clotting factors proteins? |
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Definition
No, Calcium is not. The rest are. |
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Term
How do the clotting factors function as enzymes? |
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Definition
They activate eachother causing a chemical reaction |
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Term
What is the end point of the intrinsic and extrinsic pathways? |
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Definition
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Term
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Definition
stabilizes the platelet plug |
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Term
If any clotting factors are missing or defective, what happens? |
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Definition
It inhibits the making of fibrin |
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Term
What is different about factor III compared to the other clotting factors? |
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Definition
It comes from the vessel wall, not the liver |
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Term
What is the goal of the intrinsic pathway? |
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Definition
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Term
Is factor VII part of the intrinsic or extrinsic pathway? |
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Definition
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Term
What is the common pathway? |
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Definition
Where the intrinsic and extrinsic pathways come together |
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Term
How does heparin work to prevent clotting? |
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Definition
It blocks the making of thrombin from prothrombin |
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Term
How does EDTA work to prevent clotting? |
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Definition
It pulls the calcium out of the blood. This process is called chelating |
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Term
What are some signs of secondary hemostasis? |
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Definition
-Bruises and hematomas -Bleeding into the SQ, muscles, and joints |
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Term
When does fibrinolysis occur? |
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Definition
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Term
What is the process of fibrinolysis? |
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Definition
Plasminogen is converted to plasmin, which breaks down the clot allowing blood to flow again. |
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Term
Why is it important to get a detailed history on suspected hemostatic patients? |
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Definition
You need to know how long it has been going on because some disorders are inherited, and some can be caused by drugs or disease |
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Term
How soon should you do a thrombocyte count after collecting the sample? |
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Definition
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Term
If you have a "true" thrombocytopenia, will it be easy to find platelets on a smear? |
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Definition
No, you will see very few if any |
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Term
Why should you always do a manual platelet count on cat blood? |
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Definition
Cat platelet counts on machines are often inaccurate due to similar size of platelets and RBC's |
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Term
When will you see abnormal results in a thrombocyte count? |
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Definition
When numbers are less than 50,000 |
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Term
What is the clot retraction test? |
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Definition
A crude test of platelet function |
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Term
How is a clot retraction test performed? |
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Definition
Leave blood in a tube with no anticoagulant. Check tube every 30 minutes for clotting. Clot should retract from walls of tube by 50% within an hour |
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Term
When is the clotting time considered prolonged? |
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Definition
If it takes longer than 24 hours for clot to retract |
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Term
What is the Activated Clotting Time testing for? |
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Definition
It is a crude test for hemostasis, testing the intrinsic and common pathways. |
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Term
What does an ACT tube contain? |
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Definition
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Term
What are the normal ACT's for dogs and cats? |
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Definition
Dogs: 60-110 sec. Cats: 50-75 sec. |
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Term
What will cause these times to be prolonged? |
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Definition
A factor defect or severe thrombocytopenia |
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Term
What does the partial thromboplastin time (PTT) detect? |
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Definition
Intrinsic and common pathways (secondary hemostasis) |
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Term
What is it used to diagnose? |
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Definition
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Term
What type of plasma must be used? |
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Definition
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Term
What tube contains sodium citrate? |
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Definition
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Term
Why must you fill the sodium citrate tube completely? |
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Definition
You must have the correct ratio of citrate and blood (1:9) to get an accurate result |
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Term
What does the prothrombin time (PT) detect? |
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Definition
Extrinsic and common pathways (secondary hemostasis) |
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Term
When would this test have prolonged results? |
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Definition
With coumarin toxicity (also in DIC) |
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Term
What is the most common inherited bleeding disorder? |
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Definition
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Term
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Definition
A deficiency in the vW factor |
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Term
What does the vW factor do in the coagulation process? |
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Definition
-facilitates platelets to adhere to eachother -carries factor VIII |
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Term
Do signs appear as a primary or secondary disorder? |
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Definition
Primary, unless it is severe, then it would show secondary signs |
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Term
What type of plasma is used in testing for the vWf? |
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Definition
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Term
Which breed is most likely to have von Willebrand's disease? |
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Definition
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Term
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Definition
Disseminated Intravascular Coagulation |
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Term
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Definition
Massive stimulation of clotting mechanisms. Clotting everywhere! |
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Term
What is the hail mary drug given to DIC patients? |
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Definition
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Term
What are some common causes of DIC? |
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Definition
-Pancreatitis -Heartworm Disease -RMSF and ICH -FIP and FeLV -GDV -Neoplasia |
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Term
How can you diagnose DIC? |
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Definition
-Bleeding/organ failure -Thrombocytopenia -All coagulation tests will be prolonged |
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Term
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Definition
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Term
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Definition
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Term
How do you detect hemophilia? |
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Definition
There will be a prolonged PTT/factor assays |
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Term
What happens in a coumarin/warfarin toxicity? |
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Definition
It blocks vitamin K and there is a deficiency in factor VII |
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Term
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Definition
Often from a patient history as well as prolonged PT |
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