Term
| What are bone marrow samples used for? |
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Definition
-diagnose and monitor disease
-need good aspirate, smear prep, staining, slide eval, and correlation w/ lab data
-aspirates are more common than biopsies |
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Term
| Things that make you do a bone marrow aspirate |
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Definition
-hematologic abnormalities (cytopenia, morphology, cell pop)
-investigate history findings (fever, diag neoplasia)
-cause of lytic/prolif bone lesion
-explain chem findings
-diag infection |
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Term
fine needle aspirate
Pros and Cons |
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Definition
pro: evaluate cell morphology, no special fixation req, faster turn around.
con: may not reflect true cellularity, # of megakaryocyte, or focal processes, hemodilution |
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Term
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Definition
pro: more acc in determining true cellularity, better at discerning conditions
con: slower turn around, hard to ID and eval cells |
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Term
| If an animal is dead, what's the time limit to get a sample for a bone marrow aspirate? |
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Definition
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Term
| instruments to aspirate bone marrow |
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Definition
-15-18ga 1-2 in bone marrow asp needle
-10-12 mL syringe
-2-3% EDTA/saline sterile soln...if waiting >30 min to put on slide |
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Term
Sites to collect bone marrow:
-Dog/Cat
-Equine/Bovine |
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Definition
-iliac crest, trochanter fossa, prox humerus, sternebrae (careful close to lungs), costochondral jxn
-sternebrae, rib |
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Term
| Don't send cytology in the same container as _____. why? |
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Definition
| formalin b/c the fumes disrupt staining |
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Term
| Always do ____ with a bone marrow aspirate. |
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Definition
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Term
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Definition
| the arrest of bleeding (hemorrhage) and maintenance of flow |
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Term
| Three components that contribute to Hemostasis |
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Definition
| Blood vessel wall, Plateles, Coagulation factors |
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Term
| What's in the blood vessel wall? |
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Definition
| endothelial cells, subendothelial collagen, subendothelial smooth muscle. All must be present in adequate quantities to be normal. |
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Term
| *****Common Clinical Associations with Bleeding Disorders***** |
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Definition
| Thrombocytopenia, Vit K antagonist, disseminated intravascular coagulation (DIC), liver failure, Vit K def due to bile duct obstruction |
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Term
| Causes of thrombocytopenia |
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Definition
| destruction, consumption, decreased production |
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Term
|
Definition
| control coagulation. physical barrier, "non-wettable" surface (thromboresistant) |
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Term
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Definition
| breaks down clot so it can be recanulated |
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Term
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Definition
| contraction of damaged vessel, exp of collagen fibers-decrease blood flow, decrease shear stress, production of vonwillebrand factor. |
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Term
| Events following injury of blood vessels and subsequent hemorrhage: |
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Definition
Blood vessel contraction-reduce blood flow to injured areas.
Platelet adhesion to injured site: Primary Hemostasis (platelet plug)
Activation of coagulation system: Secondary Hemostasis (formation of fibrin) |
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Term
|
Definition
Platelets (formed in bone marrow, cytoplasmic fragments of megakaryocytes)
Platelet prod stimulated by thrombopoietin
Larger platelets are caled megaplaelets/giant platelets--sign of increased usage or destruction of platelets. |
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Term
| 3 Steps of platelet plug formation |
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Definition
| Adhesion, release reaction, aggregation |
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Term
| Adhesion of platelet, step 1 of Platelet plug formation |
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Definition
-blood vessel injury results in exposure of subendothelial structures to circulating blood
-subendothelial structures include collagen and smooth muscle
-von Willebrand factor acts as bridge btwn platlets and subendothelial collagen resulting in adhesion of platelets to collagen |
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Term
| Granule release reaction, step 2 of platelet plug |
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Definition
-platelets adhere to subendothelial collagen--release their granular contents
-contents promote clotting: Calcium (cofactor in coagulation system), vonWillebrand factor (platelet adhesion to subendothelial collagen), ADP (induces expression of platelet surface receptors that bind to fibrinogen), Fibrinogen (causes platelets to adhere to each other) |
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Term
| Platelet aggregation, step 3 of platelet plug |
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Definition
| because of granule contents-platelets adhere to each other. |
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Term
|
Definition
-if defect is small and blood flow is slow=platelet plug is enough
-defect is large, blood is swift--need stabilization of plug w/ fibrin. Formation of fibrin is from coagulation system.
-Intrinsic and extrinsic pathways of coagulation |
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Term
| Factor III (tissue thromboplastin) |
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Definition
| endothelial transmembrane protein w/ assoc cell membrane phospholipids |
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Term
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Definition
| X->X+Ca,PF-3 convert Prothrombin (II) --> Thrombin (IIa) which will convert Fibrinogen -> fibrin, then Fibrin + XIIIa form the stable fibrin clot |
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Term
| Intrinsic Pathway contains which factors |
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Definition
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Term
| Extrinsic Pathway contains which factors |
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Definition
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Term
| Common Pathway contains which factors |
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Definition
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Term
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Definition
| Factor III, doesn't circulate, it's attached to fibroblasts and smooth muscle cells (and some endothelial cells)--promotes activity of extrinsic system by activating Factor VII |
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Term
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Definition
| is calcium and not listed in the pathway systems. |
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Term
| Factors synthesized in the Liver |
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Definition
| I, II, V, VII, VIII, IX, X, XI, XII, XIII |
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Term
| Factors synthesized in macrophages |
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Definition
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Term
| Vitamin K dependent factors--co-factor in carboxylation of the precursors of these factors |
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Definition
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Term
| All circulating factors, except V and VIII, are ____ |
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Definition
| proteases that activate the factor following them in the cascade |
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Term
| Factor ___ & ____ are accelerators that promote more rapid activation of factors ___ and ___, respectively. |
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Definition
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Term
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Definition
-soft and gel-like and lacks strength
-strengthened with cross-links of individual fibrin molecules which is promoted by Factor XIII (fibrin stabilizing factor) |
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Term
| Production of Factor II (thrombin) starting with Tissue factor bearing cell |
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Definition
TF w/ VIIa converts IX to IXa--diffuses to platelet surface and reacts with platelet activation/aggregation on the platelet.
TF w/ VIIA converts X-> Xa which will convert II(prothrombin) to IIa(thrombin) which will cleave VIII to vWF, activate VII, and activate platelets |
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Term
|
Definition
-primary and secondary hemostatsis dont stop spontaneously.
-can become a thrombosis if unchecked and other injuries can become uncontrollable hemorrhages.
-hemostatis is controlled by by anticoagulant proteins--that dampen coagulation cascade and by fibrinolysis, which degrades fibrin and recanulates vessels.
-Anticoagulant proteins inhibit procoagulant proteins
-Fibrinolysis-fibrin is formed then lysed |
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Term
|
Definition
Antithrombin (AT)
a-2 macroglobulin
Tissue factor pathway inhibitor |
|
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Term
|
Definition
-70% of anticoagulant activity in plasma
-Heparin at endothelial surface complexes with AT
-inactivates IXa, Xa, XIa, XIIa
-very small protein and leaks through injured glomeruli
-glomerulopathies=huge loss of AT w/ subsequent thrombosis |
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Term
|
Definition
-20% of anticoag activity in plasma
-inhibits thrombin, plasmin, and kallikrein |
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Term
| Tissue factor pathway inhibitor |
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Definition
-circulates in small amount in plasma
-inhibits activated factor Xa that diffuses from site of vascular injury |
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Term
|
Definition
fibrin is formed by axn of coagulation system is dissolved.
*important because: after hemorrhage, fibrin needs to be removed for healing and need to keep clot size in check..if too big--thrombosis can form.
-performed by plasmin to make fibrin degradation products.
-FDPs interfere with platelet fxn |
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Term
|
Definition
-formed from plasminogen (activated by XIIa and Tissue plasminogen activator and epithelial plasminogen activator), incorporated into clot as it forms.
-degrades fibrin (& fibrinogen) to peptides, small peptides and **d-dimer-only produced by covalently bonded fibrin, can be assayed to see if fibrinolysis is happening in body |
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Term
| What can you assay to see if fibrinolysis is happening in the body? |
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Definition
| d-dimer--degradation product of fibrin or fibronogen |
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Term
| What can you assay to see if fibrinolysis is happening in the body? |
|
Definition
| d-dimer--degradation product of fibrin or fibronogen |
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Term
| Laboratory evaluations of hemostatsis |
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Definition
| Platelet count, Bleeding time, Activated Clotting time, Activated partial thromboplastic time, Prothrombin time/one-stage prothrombin time, Thrombin time, Plasma fibrinogen concentration, Assays to assess concentrations |
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Term
|
Definition
| Vascular abnormalities, platelet abnormalities, disorders of coagulation system, combined disorders |
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Term
|
Definition
-in CBC or individually by automated instruments, unopettes, monolayer of blood film
-if clump in blood=wont be counted as platelets
*normal=8 platelets/field, low=<8...look at feathered clumps, high=thrombocytosis-not a big deal. |
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Term
|
Definition
fxnal test, measure cessation of blood flow, usually buccal mucosa (shallow puncture wound), remove blood every 30 sec, time ends when bleeding stops
**animals w/ abnormal bleeding times often have petechial hemorrhages |
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|
Term
| what can cause increased bleeding time? |
|
Definition
-blood vessel abnormalities (esp abnormal subendothelial collagen)
-thrombocytopenia
-abnormal platelet fxn |
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|
Term
| Activated Clotting Time (ACT) |
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Definition
| Tests the intrinsic and common systems |
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Term
|
Definition
-may be affected by severe thrombocytopenia
-WHOLE blood collected in warmed vacutainer tube w/ diatomaceous earth (activates factor XII & XI).
-make sure not contaminated w/ tissue thromboplastin (activates extrinsic system) found in extravascular tissue fluid.
-time stops when see a soft clot
-need phospholipid, if platelet <10,000 amt of phosopholipid is inadequat eand prolong time |
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Term
| Activated partial thromboplastic time (APTT) |
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Definition
| Tests the intrinsic and common system |
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Term
|
Definition
-Calcium (contact activator) and phospholipid are added to citrated plasma from patient.
-contact activator activates factors XI and XII and extrinsic common systems prod fibrin |
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Term
| Prothrombin time (PT)/ One-stage prothrombin time (OSPT) |
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Definition
| Tests the extrinsic and common systems |
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Term
| Collection for PT/OSPT test |
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Definition
| -Calcium and tissue thromboplastin added to citrated plasma, extrinsic system activated when tissue thromblastin complexes with factor VIIa..activates factor X in common system..fibrin is produced. |
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Term
|
Definition
| tests quantity of fibrinogen and functionality of fibrin |
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Term
|
Definition
add thrombin and calicum to citrated plasma...thrombin with Ca will convert fibrinogen to fibrin.
-normal TT=normal plasma fibrinogen concentration
-increased TT=decreased plasma fibrinogen concentration...may result from increased consumption of fibrinogen (DIC) or decreased prod of fibrinogen (hepatic failure) |
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Term
| Plasma fibrinogen concentration |
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Definition
| masured by heat precipitation or immunologic methods (more accurate) |
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Term
| Assays to assess concentrations of individual coagulation factors |
|
Definition
| need to go to laboratory, citrated plasma samples required |
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Term
| Vascular disorders resulting in hemorrhage are inherited or acquired |
|
Definition
Interited-Ehlers-Danlos syndrome=abnormal collagen formation leads to decreased platelet adhesion. rare.
Aquired: Vasculitis (inflammation of vessel wall disrupts vascular integrity. from immune mediated disorders->ag-ab complexes). Scurvy (vit C deficiency=deficient collagen formation causes decreased platelet adhesion and hemorrhage). Cushing's syndrome (decreased collagen prod causes hemorrhage b/c decreased platelet adhesion) |
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Term
| Typical lab with hemorrhaging animals from vascular disorders |
|
Definition
bleeding time=prolonged
act=normal
aptt=normal
pt=normal
tt=normal |
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Term
| Platelet disorders resulting in hemorrhage |
|
Definition
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|
Term
| von Willebrand's disease is a disease of the primary or secondary hemostatic system? |
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Definition
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|
Term
| Contents in a platelet (granule contents) |
|
Definition
| fibrinogen, calcium, von willibrand facotr, adenosine diphsophate |
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|
Term
| Granule conents stimulate |
|
Definition
| aggregation of platelets and formation of a platelet plug |
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|
Term
| Three differentials for erros in primary hemostasis |
|
Definition
problem with the vessel
deficiency in platelet # or fxn
von Willebrand's disease |
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