| Question | Answer |
| What is the normal plt count range? | 150,000 to 440,000 x 10^9 /L |
| List some important molecules for coagulation. | Calcium, Vitamin K, fibrinogen |
| What does TPO do? | It's a major humoral component that causes platelet proliferation. It also regulates the production and release of plt. |
| How does TPO maintain constant # of platelets in the blood? | They have a receptor mpl(CD110) which can bind to the megakaryotcye and circulating platelets. |
| Where are megakaryocytes located in the bone marrow? | Near the sinuses. |
| Where are most of the platelets in the body? | Blood stream (~2/3) |
| What is a site of plt sequestering? | The spleen (~1/3) |
| What's the average lifespan of a plt? | 9.5 days |
| What portion of the megakaryocye is platelets composed of? | The cytoplasm. |
| What is the demarcation membrane system? | They are small areas in the cytoplasm that separated. |
| When plts are decreased, how much TPO is present compared to normal and what does it bind to? | TPO is increased and binds to megakaryocyte to increase plt release/shedding |
| What's the main function of the peripheral zone? | Activation, adhesion, aggregation. |
| What are the main components of the peripheral plt zone? | Glycocalyx, phospholipid bilayer, Integral proteins. |
| Structural zone contains? | microtubules, cytoskeletal network, intermediate filaments. |
| What's the purpose of the structural zone? | To provide structure and support. |
| What disease does the sugar H2O test for? | Paroxysmal nocturnal hemoglobinuria; + = presumptive diagnosis but need to do flow cytometry to confirm. |
| What type of RBC's does the Osmotic fragility test for? | Spherocytes, they lyse faster than normal RBC's in hypotonic solns |
| What are common reasons to perform a sed rate? | To see if there is an inflammatory process taking place, multiple myeloma, PID, Lupus, RA, kidney disease. |
| What is the normal reference range for sed rate? | 0 to 20 mm/hr |
| What other test is almost always requested with a sed rate? | C-reactive protein |
| How is the extrinsic pathway activated? | By tissue damage which releases Ca+, or by release of tissue thromboplastin. |
| What factors are unique to the extrinsic pathway? | VII and III (Tissue Factor/TF) |
| Which factors are used in the common pathway? | X, V, II, I |
| Which factors are unique to the intrinsic pathway? | PK, HK, XII, XI, VIII, IX |
| Which pathway uses the aPTT test and which medication can be monitored by this test? | Intrinsic pathway---> can measure heparin or monitor Hemophilia A + B |
| Which test is commonly used to measure the extrinsic pathway? Which medication? Are there other tests routinely performed simultaneously? | PT---> can measure how effective coumadin is, also the INR is also usually performed. |
| How does heparin stop clotting? | It prevents the cleavage of fibrinogen into fibrin. |
| How does aspirin work? | It inactivates the enzyme cyclooxygenase which will prevent the formation and release of thromboxane A2. |
| What is the organelle zone's function? What is it composed of? | Fxn= storage and secretion; contains granules, mitochondria, and glycogen. |
| List the role of each of these granules in the organelle zone: Dense bodies, alpha granules, lysosomes, peroxisomes. | Dense bodies--> non-protein mediators (i.e. ATP, ADP, serotonin)
Alpha granules--> protein mediators
Lysosomes-->Enzymes
peroxisomes--> lipid metabolism. |
| Name the membrane systems and the their functions. | Open canalicular system (Secretion of granule contents) and dense tubular systems (storage of Ca+). |
| What are the steps in coagulation? | vasoconstriction, activation, adhesion, aggregation, fibrin formation, fibrinolysis. |
| What can cause coag pathway? | ADP, thromboxane A2, aracodonic acid, von Willebrand, epinephrine, collagen |
| What causes the fibrinolysis pathway? | extrinsic: tPA, uPA
intrinsic: XIIa, XIa, kalikrein
exogenous: streptokinase |
| Inhibitors of the the fibrinolytic pathway? | plasminogen activator inhibitors (PAI), alpha2-ntiplasmin, and alpha2-macroglobulin |
| How do you calculate MCV? | hct/RBC x 10 |
| how do you calculate MCH? | hgb/rbc x 10 |
| How do you calculate MCHC? | hgb/hct x 100 |
| Name the factors in the prothrombin group. What are these factors dependent on? | II, VII, IX, X, protein c, protein s , protein z. Vitamin K dependent. |
| What is the principle of the Sysmex? | Sheath flow technology, uses impedance, radio freq. Also can determine avg size of cells from pt to pt. |
| What is the principle of the Beckman-Coulter analyzer? | Uses VCS (Volume, conductivity, scatter). Also uses hydrodynamic focusing. |
| How is the volume, conductivity, and scatter analyzed? | Volume--> impedance
Conductivity-->electromagnetic probe
Scatter--> helium neon laser |
| Name the dense body contents and their role in platelet function. | ADP--> agonist for plt
Ca-->platelet activation
Serotonin-->vasoconstriction, plt agonist |
| What is a thrombus? | A clot within a blood vessel |
| Why do you need to stop taking aspirin products within 10 days of surgery? | Aspirin causes an irreversible disruption in the platelet function (Inhibition of COX1). This gives your body time to make new platelets. |
| What is the reference range for WBC's in an adult? | 4-11 x 10^9/L |
| List some things that could affect the WBC concentration. | Time of day, exercise, pregnancy, infection, age, race, gender, stress. |
| What do CSFs do? | They are cytokines that made by endothelial cells, marrow fibroblasts, and wbc's. Regulate production and development of wbc. |
| What is found in the secondary granules of granulocytes? | histaminase, collagenase, and lactoferrin (pinkish colored) |
| Azurophillic (Primary) granules contain what? | myeloperoxidase (purple/blue colored) |
| Where are the granulocyte pools? | BM, PB, marginating in BV, tissues |
| What are the functions of the BM pool? | proliferation, maturation, Storage. |
| Auer rods are only seen in which cell line? | Myeloloid |
| What is the first identifiable granulocytic stage? | Myeloblast |
