Platelets Flashcards
What is haematology?
The study of blood, used as part of a diagnostic process
What is histology?
The study of tissues using techniques like biopsies and staining
What is cytology?
The study of cells using microscopic examination
What is serology?
The study of serum, focusing on proteins like antibodies.
What is thrombopoiesis?
The process of platelet production in the bone marrow
What is thrombocytopenia?
A condition where platelet concentration is too low
What are the two main cellular diagnostic techniques?
- Histology → Uses biopsies and staining.
- Cytology → Microscopic examination of cells
What are some methods of cytology sampling?
- Skin scrape.
- Swabs (e.g., eye, nose, vagina).
- Lavage (fluid collection from internal cavities).
- Fine needle aspiration (sample from lumps or joints).
What are the main components of blood?
- Platelets (for clotting).
- Red blood cells (RBCs).
- White blood cells (WBCs).
- Plasma (liquid portion).
What is the buffy coat in blood?
A thin layer formed after centrifugation, containing platelets and WBCs
What is the difference between plasma and serum?
- Plasma contains clotting factors.
- Serum is plasma without clotting components.
What are the main components of serum?
- 90% water.
- Electrolytes (Na+, Ca2+).
- Nutrients.
- Organic waste (e.g., urea).
- Proteins (albumins, antibodies, fibrinogen).
hat are the traditional techniques for haematology testing?
- Microscopy (e.g., blood smear).
- Density tests.
- Spectrophotometry.
What is a Complete Blood Count (CBC) used for?
- Measures platelets, RBCs, and WBCs.
- Used to diagnose diseases like Strangles.
What anticoagulants are used for different blood tests?
- EDTA → For cell counts.
- Heparin → For biochemistry.
- Sodium citrate → For coagulation tests.
What are platelets, and how are they formed?
- Platelets are cytoplasmic fragments derived from megakaryocytes.
- Their main function is coagulation (blood clotting).
What molecules do platelets release for wound healing?
- Vascular endothelial growth factor (VEGF).
- Platelet-derived growth factor (PDGF).
What is Platelet-Rich Plasma (PRP), and how is it used?
- A treatment used in equine wound healing.
- Its effectiveness is still being researched.
Where are platelets produced?
In the bone marrow
How long do platelets live?
5-8 days
What happens to platelets when they are activated?
- They change from disc-shaped to irregular.
- They develop pseudopodia to aid in coagulation.
How does platelet size differ in cats?
- Feline platelets are twice the size of normal platelets.
- This can cause errors in automated haematology analysers.
What is the first step in platelet aggregation?
Endothelial damage, exposing collagen and von Willebrand factor (vWF)
What is the second step in platelet aggregation?
Platelets detect vWF and collagen, change shape, and form a plug
What is the third step in platelet aggregation?
- Clotting factors are activated, including:
- Fibrinogen.
- Prothrombin.
What is the fourth step in platelet aggregation?
- Platelets release prothrombin activator (PA).
- PA converts prothrombin → thrombin.
- Thrombin cleaves fibrinogen → fibrin, forming the clot.
What are the main diseases related to platelet function?
- Thrombocytopenia (low platelet count).
- Von Willebrand disease (VWD) (defective platelet function).
What causes thrombocytopenia?
- Incorrect sampling (clumping).
- Vascular injury.
- Specific infections (e.g., Ehrlichia bacteria).
- Bone marrow diseases.
- Immune-mediated destruction.
What is Von Willebrand Disease (VWD)?
- A hereditary disorder where platelets cannot properly bind due to defective vWF antigen.
- Most common bleeding disorder in dogs.
What dog breeds are most affected by VWD?
- Doberman Pinschers (73%).
- Welsh Corgis (43%).
- German Shepherds (35%).
- Golden Retrievers (30%).
- Poodles (30%).
What are the symptoms of Von Willebrand Disease?
- Bleeding gums (gingival bleeding).
- Blood in urine (hematuria).
- Excessive bleeding after wounds.
How is Von Willebrand Disease diagnosed?
- Normal platelet count but low vWF antigen.
- Detected by ELISA assay.
