Hematology & Hemostasis Flashcards
(268 cards)
1
Q
Agranulocytes
A
The white blood cell group that has no visible cytoplasmic granules
2
Q
Erythropoiesis
A
The production of erythrocytes
3
Q
Erythropoietin
A
The hormone that stimulates erythropoietic activity in the bone marrow
4
Q
Granulocytes
A
Any cell with distinct cytoplasmic granules
5
Q
Hematopoiesis
A
The production of blood cells and platelets
6
Q
Left shift
A
The presence of increased numbers of immature cells in a peripheral blood sample
7
Q
Leukemia
A
A condition characterized by the presence of neoplastic cells in the blood or bone marrow
8
Q
Leukemoid Response
A
The exhibition of blood counts (particularly leukocytosis) and sometimes other clinical findings that resemble those of leukemia
9
Q
Leukocytosis
A
The presence of increased numbers of leukocytes in the blood
10
Q
Leukopoiesis
A
The production of leukocytes
11
Q
Lymphopenia
A
The presence of decreased numbers of leukocytes in a peripheral blood sample
12
Q
Pancytopenia
A
13
Q
Pluripotent Stem Cell
A
A cell capable of differentiating into one of many cell types
14
Q
Thrombocytes
A
Platelets
Cytoplasmic Fragments of bone marrow megakaryocytes
15
Q
Thrombopoiesis
A
The production of platelets
16
Q
Thrombopoietin
A
17
Q
List the organs involved in hematopoiesis
A
Prenatal: liver, spleen, thymus, red bone marrow
Adult: primarily red bone marrow but may revert to liver and spleen if stressed
18
Q
Differentiate between hematopoiesis in prenatal and adult animals
A
In the adult animal, blood cells are formed in the bone marrow.
In the prenatal animal, blood cells are formed at multiple organ sites, such as the liver and spleen.
19
Q
Explain the role of erythropoietin in hematopoiesis
A
Erythropoiesis is stimulated by the hormone erythropoietin. Cells in the kidney monitor the tissue oxygen levels and stimulate the release of erythropoietin in response to tissue hypoxia. Erythropoietin acts directly on the erythrocyte stem cell located in the bone marrow, the hemocytoblast, and stimulates it to differentiate into a rubriblast.
20
Q
List the cells in the erthyrocyte maturation series.
A
Rubriblast
Prorubricyte
Basophilic rubricyte
Polychromatophilic rubricyte
Metarubricyte
Reticulocyte
21
Q
List the cells in the leukocyte maturation series.
A
22
Q
Describe the formation of platelets
A
Thrombopoietin is produced primarily in the liver.
The progenitor cell develops into a megakaryoblast and then develops into a promegakaryocyte and then a megakaryocyte
The cytoplasm extends into marrow sinuses where it is sheared off by the flow of blood
These proplatelets eventually fragment further into platelets
23
Q
Anticoagulants
A
Any substance that inhibits or prevents clotting
24
Q
Citrate
A
Any salt of citric acid
Citrate salts are used as temporary anticoagulants for studies of blood coagulation
25
Ethylenediaminetetraacetic acid
An anticoagulant that binds calcium
26
Heparin
An acid mucopolysaccharide that is present in many tissues especially the liver and lungs and that has potent anticoagulant properties
27
Oxalate
Am anion of oxalic acid
28
Plasma
The fluid portion of the blood
29
Serum
The fluid portion of blood after it has clotted
It doesn't contain cells or coagulation proteins
30
Sodium fluoride
31
Vacutainer
A glass tube with a rubber stoprr from which air can be removed to create a vacuum
Usually used to draw blood
32
Describe the procedures for the collection of blood samples from small and large animals
The collection site should be cleaned and swabbed with alcohol. The animal must be restrained, preferably with minimal manual control.
The preferred method of blood collection is the use of a vacuum system (e.g., Vacutainer) that’s composed of a needle, a needle holder, and collection tubes. The collection tubes can be plain sterile tubes with or without anticoagulants.
33
List the commonly used blood collection sites for various species
Dog: cephalic, jugular, and saphenous
Cat: cephalic and jugular
Horse: jugular
Cattle: coccygeal and jugular
Bird: jugular and medial metatarsal
Rabbit: ear
Rodent: tail
34
List the commonly used anticoagulants and the purpose and mode of action for each
Heparin: used for critical RBC measurements - MOA: antithrombin
EDTA: used for hematology - MOA: chelates calcium
Oxalates: used for coagulation - MOA: chelates calcium
Citrates: used for coagulation and transfusions - MOA: chelates calcium
Sodium fluoride: used for preserving blood glucose - MOA: chelates calcium
35
List the equipment needed for the collection of blood samples
Needle and syringe
- largest needle comfortable for animal
- syringe must be closest to sample size needed
Vacutainer
- select the correct size and fill the correct volume
36
Describe the procedures for preparing blood samples for evaluation.
- Remove the needle from the syringe before transferring the blood from the syringe to the tube
- Gently invert any tubes containing anticoagulant to ensure proper mixing with blood
- Label the tube with date and time, patient name and ID number, and owner name
37
List the safe blood volumes that be withdrawn from patients
Well-hydrated animal with a PCV 50%
- 10mL blood = 5mL fluid
Dehydrated animals with a PCV 70%
- 10mL blood = 5mL fluid
38
Calculate safe blood volumes that can be withdrawn from patients
Well-hydrated animal (PCV 50%)
- 10mL blood = 5mL fluid
Dehydrated animal (PCV 70%)
- 10mL blood = 3mL fluid
39
Anemia
40
Complete blood count
41
Neubauer rulings
A specific pattern of precise markings in a hematocytometer slide that facilitates the counting of leukocytes, erythrocytes, and platelets in the blood and of all cells in other fluids
42
Polycythemia
Increased number of RBCs
43
Red cell distribution width
44
List the types of hematology analyzers available for use in the veterinary practice
Impedance analyzers
Laser flow cytometry analyzers
Quantitative Buffy coat analysis system
45
Describe the principle of the electrical impedance analyzer
1. Passage of electric current across 2 electrodes separated by a glass tube with a small opening or aperture
2. Electrolyte fluid conducts the current
3. Counting by moving a specific volume of cells in the Electrolyte solution through the aperture by use of a vacuum or positive pressure
4. Cells are poor conductors and impede the flow of the current (cell size based on change in current)
46
Describe the laser flow cytometry test principles
Uses focused laser beams to evaluate the size and density (cells scatter light differently)
47
Describe the principle of quantitative buffy coat analysis
Uses differential centrifugation and staining to estimate cells
Uses a specialized microhematocrit tube
Gives hematocrit value and estimates WBC and platelet concentrations
48
Describe the care and maintenance of automated hematology analyzers
Cleaning and quality control are essential for assuring the accuracy of the test results
49
Describe the procedures for the manual counting of cells
Performed with a hematocytometer
50
Define histogram and explain the use of histogram
A graphic display of a frequency distribution that is represented by a series of rectangles that divide the data into classes
Provides a visual representation of the numbers and sizes of the cells present kn a sample
51
Buffy coat
A layer of material above the packed erythrocytes after centrifugation
Consists primarily of leukocytes and thrombocytes
52
Erythrocyte indices
Calculated values that provide the average volume and hemoglobin concentrations of erythrocytes in a peripheral blood sample
53
Hemoglobin
The oxygen-carrying pigment of erythrocytes, which is formed by developing erythrocytes in the bone marrow
54
Icterus
Abnormal yellowish discoloration of skin, mucous membranes, or plasma as a result of an increased concentration of bile pigments
55
Lipemia
The presence of fatty material in plasma or serum
56
Mean corpuscular hemoglobin (MCH)
Mean weight of hemoglobin contained in the average RBC
Divide the hemoglobin concentration by the RB concentration of multiply by 10
57
Mean corpuscular hemoglobin concentration
Concentration of hemoglobin in the average RBC
Divide the hemoglobin concentration by the PCV and multiply by 100
58
Mean corpuscular volume
Measures the average size of RBCs
Divide PCV by RBC concentration and multiply by 10
59
Methemoglobin
The form of hemoglobin that contains oxidized iron
Inefficient at oxygen transport
60
Microhematocrit
Refers to the use of a capillary tube and a high-speed centrifuge to determine the PCV
61
Oxyhemoglobin
62
Packed cell volume
The ratio of RBCs to total plasma volume
63
Describe the procedure for performing a PCV test with the microhematocrit method
The procedure requires that an anticoagulated blood sample be placed in a capillary tube. The tube is then placed in the centrifuge and spun for five minutes. The blood components separate into different layers according to their relative weights. The PCV represents the ratio of the height of the column of red blood cells relative to the total volume in the capillary tube. The color and clarity of the plasma column is also reported as part of the PCV test.
64
Describe the procedure for calibrating the centrifuge for optimum MCT spin time
1. Use a stopwatch to verify the centrifuge timer operation. Run several trdtd at different time intervals and repeat each at least twice to verify reproducibility.
2. Use a tachometer to check the centrifuge speed
3. Verify the min time required to obtain an accurate PCV
4. The min time needed to achieve optimal packing of the RBCs should be checked with a Hematocrit Calibration Plot Chart
65
List the layers in the centrifuge microhematocrit tube in order from bottom to top
Clay plug
RBCs
Buffy coat (WBCs and platelets)
Plasma
66
Explain the significance of reddish, yellow, and cloudy plasma colors in the centrifuged microhematocrit tube
Normal - clear to pale yellow
Cloudy - lipemic
Reddish tinge - hemolyzed
Deep yellow - icteric
67
Differentiate among oxyhemoglobin, methemoglobin, and sulfhemoglobin
Oxyhemoglobin - oxygen replaces CO2 in respiration
Methemoglobin - occurs naturally
Sulfhemoglobin - results from cell aging
68
Absolute value
The number of each type of leukocyte in peripheral blood
Calculated by multiplying the relative percentage from the differential count by the total WBC count
69
Basophil
A granular leukocyte with an irregularly shaped, relatively pale-staining nucleus that is partially constricted into 2 lobes and with cytoplasm that contains coarse bluish-black granules of variable size
70
Coverslip smear
A method of preparing a blood film with the use of 2 coverslips
71
Eosin
A type of pink to red acid dye that is a component of differential stains
Primarily used for the routine staining of blood films
72
Eosinophil
A granulocyte with granules that have an affinity for the acidic components of stains
73
Heterophil
A leukocyte of avian, reptile, and some fish species that contains prominent eosinophilic granules
Functionally equivalent to the mammalian neutrophil
74
Lymphocyte
A leukocyte that is involved in the inflammatory process and that also has roles in humoral and cell-mediated immunity
75
Megathrombocytes
Abnormally large platelets that are usually newly formed
Seen in greater numbers during an increase in platelet production
76
Methanol
Methyl alcohol
77
Methylene blue
78
Monocyte
A precursor cell representing a stage in the development of the tissue macrophage
After a monocyte leaves the bloodstream and enters tissue at the site of inflammation, it becomes an activated macrophage
79
Neutrophil
A leukocyte that functions to phagocytize infectious agents and cellular debris
Plays a major role in the inflammatory process
80
Neutrophilia
An abnormal increase in the number of neutrophils seen in a peripheral blood sample
81
Platelet
Irregular, disc-shaped fragments of mrgakaryocytes in the blood that assist with blood clotting
82
Romanowsky stain
83
Wedge smear
84
Wright's stain
85
Wright-Giemsa stain
86
Describe the procedure for preparing a Wedge smear to perform a differential blood cell count
1. Place a small drop of blood at the end of a clean glass slide using a microhematocrit tube or the end of a wooden applicator stick. Place the slide on a flat surface or suspend it in midair between the thumb and forefinger
2. Hold a second slide at a 30-degree angle and pull it back into contact with the drop of blood, spreading the blood along the edge of the spreader slide. Push the spreader slide forward in a rapid, steady, even motion to produce a blood smear that is thick at one end and tapers to a thin, feathered edge.
3. Air dry the smear by air waving to fix the cells.
4. Label the slide at the thick end of the smear.
5. Stain the smear with Wright's stain or a Romanowsky stain.
6. After staining, rinse the slide with distilled water.
87
Describe the procedure for preparing a coverslip smear to perform a differential blood cell count.
1. Place a small drop of blood in the center of a clean, square coverslip
2. Place the second coverslip diagonally on top of the first
3. Allow the blood to spread evenly between the 2 surfaces until the blood almost fills the area between coverslips
4. Pull the coverslips apart in a single smooth motion
5. Wave the coverslips gently to allow them to air dry.
88
Describe the procedure for the proper staining of the blood smear.
Fix the slide with methanol for at least 60 seconds before staining
Depending on the stain, the average time to immerse the slide is 30 seconds for each component
89
Troubleshoot stain quality on a blood smear.
Excessive blue staining
Excessive pink staining
Weak staining
Uneven staining
Precipate on preparation
90
Describe the procedure for performing a leukocyte absolute value calculation.
The differential count is referred to as the relative cell count because it provides enumeration of the percentage of each type of white blood cell present in the sample (relative to 100 cells). The absolute cell count for each type of cell is then calculated by multiplying the relative percentage by the total white blood cell count.
91
Describe the procedure for performing a platelet estimate.
A platelet estimate is performed by counting the number of platelets seen on differential blood film as averaged over 10 oil-immersion fields. The presence of an average of seven to ten platelets is reported as adequate. Another indirect measure of platelet numbers is performed by counting the number of platelets seen per 100 WBCs on the differential blood film. This number is then used to calculate the platelet estimate according to the equation (thrombocytes per 100 leukocytes x WBC count per microliter = thrombocytes per microliter
92
Acanthocyte
An erythrocyte with spiny projections of varying lengths distributed irregularly over its surface
93
Anisocytosis
94
Anulocyte
95
Apoptosis
The death of single cells by a process involving shrinkage, rapid fragmentation, and the engulfment of the fragments by neighboring cells and macrophages
96
Atypical lymphocyte
A lymphocyte with morphologic abnormalities, including azurophilic granules, increased cytoplasmic basophilia, overly abundant cytoplasm, or a larger and more convoluted nucleus than seen in normal lymphocytes
97
Autoagglutination
The clumping or agglutination of an individual's cells by that individual's own serum, usually because of the presence of antibodies
98
Basophilic stippling
Erythrocytes that are characterized by small, blue-staining granules
This represents the presence of residual RNA
99
Codocyte
An erythrocyte that is characterized by an increased membrane surface area relative to the cell's volume
100
Dacryocyte
An abnormal erythrocyte that is shaped like a teardrop
101
Döhle body
Small, gray-blue areas that represent ribosome and that are seen in cytoplasm of some immature and toxic granulocytes
102
Drepanocyte
A morphologic abnormality of erythrocytes that is characterized by sickle-shaped cells
103
Echinocyte
An erythrocyte with multiple small projections that are evenly spaced over the cell circumference
104
Heinz body
Round structures of erythrocytes that represent denatured hemoglobin and that appear as a pale area when stained with Wright's stain
105
Howell-Jolly body
Basophilic inclusions of young erythrocytes that represent nuclear remnants
106
Hyperchromatophilic
A term that refers to a cell that appears darker than normal on a peripheral blood sample
107
Hypersegmented
A neutrophil with more than 5 nuclear lobes
108
Hypochromasia
The presence of erythrocytes with decreased staining intensity as a result of a decrease in hemoglobin concentration
109
Hyposegmentation
A leukocyte with a nucleus with fewer than the normal number of nuclear lobes
110
Karyolysis
The degeneration or dissolution of a cell nucleus
111
Karyorrhexis
The fragmentation of a cell nucleus
112
Keratocyte
An abnormally shaped erythrocyte that appears to have horns
113
Leptocyte
An erythrocyte that is characterized by an increased membrane surface area relative to the cell volume
114
Macrocytosis
A condition in which a cell is abnormally large
115
Microcytosis
A cell that appears much smaller than normal
116
Nucleated erythrocyte
An immature red blood cell that still contains a nucleus
117
Pelger-Huët anomaly
An inherited anomaly that is characterized by the appearance of bilobed neutrophils in a peripheral blood sample
118
Poikilocytosis
Any abnormal cell shape
119
Pyknosis
The presence of condensed nuclear chromatin in a degenerating cell
120
Reactive lymphocyte
121
Rouleaux
An arrangement of erythrocytes that appears as a column or stack
122
Schistocyte
Fragmented erythrocytes that are usually formed as a result of shearing of the red cell by intravascular trauma
123
Smudge cell
A leukocyte that has ruptured
124
Spherocyte
An intensely stained erythrocyte that has reduced or no central pallor
125
Stomatocyte
An erythrocyte with a linear area of central pallor
126
Target cell
A leptocyte with a peripheral ring of cytoplasm surrounded by a clear area and a dense, central, rounded area of pigment
127
Torocyte
128
Toxic granulation
Appearance of numerous large granules in the cytoplasm of neutrophils that range in color from purplish-blue to red
Seen in most infectious diseases
129
Describe methods for semiquantifying morphologic changes.
2 Methods:
- Scale of 1+, 2+, 3+, 4+ toindicated relative percentages of cells with changes
- 1+ = 5-10%
- 2+ = 10-25%
- 3+ = approx 50%
- 4+ = more than 75%
- Slight, moderate, marked
- slight = 10%
- moderate = 25%
- marked = 50%
130
List the types of morphologic changes seen in WBCs.
Hypersegmentation
Karyorrhexis/karyolysis/pyknosis
Döhle bodies
Vacuolization
Toxic granulation
Parasites
Juvenile forms
Reactive lymphocytes
Atypical lymphocytes
Basket cells
131
Hypersegmentation
Neutrophil nucleus with more than 5 lobes
Associated with a variety of conditions such as chronic infection, pernicious anemia, and steroid use
132
Karyorrhexis/Karyolysis/Pyknosis
Condensed, lysed, or damaged nucleus
When seen in WBCs in the peripheral circulation, caused by the use of inappropriate anticoagulants (Ex. Artifact)
133
Döhle Bodies
Coarse cytoplasmic inclusions representing ribosome material
Common in felines
Might be seen with chronic bacterial infection and some viral diseases
134
Vacuolization
One of several toxic changes seen in both lymphocytes and neutrophils
Associated with septicemia
Also produced as an artifact if a sample is held for an extended time in anticoagulant
135
Toxic granulation
Appearance of large granules in the cytoplasm of neutrophils that range in color from purplish-blue to red
Seen in most infectious diseases
136
Parasites
A number of parasites, including Ehrlichia and Histoplasma, might be seen within leukocytes, but they're usually so small in number that they're best demonstrated with a Buffy coat smear
137
Juvenile forms
Immature WBCs seen in a variety of conditions resulting from increased bone marrow activity
In most species, small numbers of band neutrophils can normally be seen in peripheral circulation
The appearance of increased numbers of band cells and/or more immature forms of any of the leukocytes is referred to as a left shift
138
Reactive lymphocytes
Cells with dark blue cytoplasm and darker nucleus
Seen in chronic infection
139
Atypical lymphocytes
Represent a variety of changes within lymphocytes, including eosinophilic cytoplasm and changes in nuclear texture
140
Basket cells
Common term used to describe degenerative WBCs that have ruptured
Also referred as smudge cells
Can be an artifact if blood is held too long before making a smear
Also associated with leukemia
141
Describe the types of morphologic changes seen in RBCs
Size changes
Shape changes
Color changes
Cell behavior changes
Appearance of inclusion bodies
142
Discuss what is meant by the term toxic change
Common disease-induced cytoplasm changes in neutrophils
Associated with inflammation, infection, drug toxicity
Dogs- bacterial infection
Cats- common in not severely ill cats
Ex. Cytoplasmic basophilia, Döhle bodies, toxic granulation, giantism
Caused by decreased length of time in the neutrophil maturation process with bone marrow
143
List the terms used to describe abnormal changes in RBC size
Anisocytosis
Macrocytosis
Microcytosis
144
Anisocytosis
Variation in RBC size seen in splenic or liver disorders
A sign of regeneration of anemia
145
Macrocytosis
Larger-than-normal immature RBCs that appear as reticulocytes when new methylene blue stain is used
146
Microcytosis
Smaller-than-normal RBCs often seen in iron-deficient patients
147
List the terms used to describe abnormal changes in RBC shape.
Normocytes
Poikilocytes
Schistocytes
Acanthocytes
Echinocytes
Spherocytes
Stomatocytes
Leptocytes
148
Normocytes
Biconcave disks in canines
Round cells in felines
149
Poikilocytes
A genetic term for any abnormally shaped cell
Specific abnormality should be further characterized as appropriate
150
Schistocytes
Fragmented RBCs caused by vascular trauma
Seen in disseminated intravascular coagulation and neoplasia
151
Acanthocytes
RBCs with long, irregular projections from the cell surface
152
Echinocytes
RBCs with a scalloped border (regular projections) from the cell surface
153
Spherocytes
Small, dense RBCs with no area of central pallor
154
Stomatocytes
RBCs with a slitlike center opening
Seen in the regeneration of anemia
155
Leptocytes
RBCs with an increase in membrane surface relative to cell volume
Also called target cells or codocytes
156
List the terms used to describe abnormal changes in RBC arrangement.
Rouleaux
Autoagglutination
157
Rouleaux formation
Stacking of erythrocytes
Normal in horses and may be present in cats and pigs
Artifact of prolonged storage
158
Autoagglutination
Occurs in immune-mediated disorders
Cells coat with antibodies, which result in bridges and clumps
Differentiate from Rouleaux by a drop of saline
159
List the terms used to describe abnormal changes in RBC color.
Polychromasia
Hypochromasia
Hyperchromic or hyperchromatophilic
160
Polychromasia
Cells that exhibit a bluish tint
161
Hypochromasia
Cells with an increase in the area of central pallor
162
Hyperchromic or hyperchromatophilic
Cells that appear darker than normal
Gives appearance of too much hemoglobin
Usually microcytes or spherocytes
163
List and describe the parasites that may be seen on a blood smear
Dirofilaria immitis
Mycoplasma haemofelis- small, coccoid, rod-shaped or ringlike, and dark
Erhlichia- monocytes and neutrophils
Anaplasma- small, dark-stained cocci at margin of RBC
Eperythrozoa- swine, cattle, and llamas
Cytauxzoon- feline
Babesia- cattle, horses, and dogs
164
Aspiration biopsy
Used at several sites - head of femur or humerus
Aseptic
Needle rotated and pressure applied - attach syringe and aspirate
165
Core biopsy
Sometimes provides better sample quality
Use different sites if done in conjunction with aspiration biopsy
Similar procedure but no aspiration - rotate needle to cut piece of bone from the cortex
166
Erythrocyte sedimentation rate
The rate RBCs fall in their own plasma will be altered in some disease states
167
Illinois sternal needle
168
Jamshidi needle
169
New methylene blue
A supravital stain that contains no fixatives
170
Reticulocyte production index
Involves the maturation time values
Divide the corrected retic percentage by the maturation time for the observed patient's PCV(Reticulocyte maturation index)
171
Reticulocytes
Immature erythrocytes that contain organelles that are lost as the cells mature
172
Rosenthal needle
173
Describe the procedure for performing the reticulocyte count.
An expression of the percentage of RBCs that are reticulocytes
The percentage of reticulocytes per 1000 erythrocytes is determined with the use of an oil-immersion lens
174
Differentiate between aggregate and punctate reticulocytes.
Aggregate - large clumps of reticulum
Punctate - contains 2 to 8 small singular basophilic granules (unique to cats)
175
Discuss indications for bone marrow evaluation.
Determined by findings of the differential blood count
- persistent unexplained pancytopenia, neutropenia, or thrombocytopenia, and nonregenerative anemia
- abnormal morphologic changes ir unexplained immature cells
- stages neoplastic diseases
- diagnosis parasitic infections - ehrlichiosis, leishmaniasis
176
Describe the collection of bone marrow aspiration and core samples.
Aspiration or removal of bone marrow core
Restraint, sedation, or local or general anesthesia are needed
Aseptic technique
Supplies:
- EDTA prepared syringes
- bone marrow needle
- no. 11 scalpel
- about 12 slides
- sutures (if needed)
177
Describe methods for preparing bone marrow samples for evaluation.
Smears must be made immediately if not mixed with EDTA (1 hour with EDTA)
Aspirate samples are prepared like blood smears
Air dry and stain with Romanowsky-type stain
178
Describe the criteria used to characterize a bone marrow sample as acellular, hypercellular, or hypocellular.
Acellular - aplasia
Hypercellular - hyperplasia
Hypocellular - hypoplasia
179
List the cells that are commonly seen in bone marrow samples.
Myeloid cells
Erythroid cells
Megakaryocytes
Macrophages
Lymphocytes
Plasma cells
Mast cells
Osteoblasts
Osteoclasts
180
Myeloid cells
Tend to be larger and stain paler than erythroid cells
Include myeloblasts, promyelocytes, myelocytes, and metamyelocytes
181
Erythroid cells
Smaller and more basophilic
Include rubriblasts, prorubricytes, rubricytes, and metarubricytes
182
Aplastic
Description of marrow with all blood cell types being decreased or absent
183
Chronic granulomatous inflammation
Increased numbers of macrophages
184
Chronic inflammation
Increased numbers of plasma cells, mature lymphocytes, and mast cells
185
Chronic pyogranulomatous inflammation
Both macrophages and neutrophils are present
186
Fibrinous inflammation
Typically involves the infiltration of the bone marrow with fibrin exudate without the presence of inflammatory cells
187
Hypercellular
Increase in overall cellularity
188
Hypocellular
Decreased cellularity
189
Lymphoproliferative disease
190
Myeloproliferative disease
191
Nonregenerative anemia
Bone marrow is unable to respond to blood loss
Reticulocytes are absent in blood
192
Regenerative anemia
Increased erythrocyte production
193
Describe the types of abnormalities seen in bone marrow samples.
Cell number
Cell morphology
Hypercellular
Hypocellular
Aplastic
194
Aplasia
Less than 25% myeloid cells
195
Basophilic hyperplasia
Basophilia in bone marrow and peripheral blood
196
Dyserythropoiesis
Abnormal erythrocyte maturation
197
Dysgranulopoiesis
Abnormal granulocyte maturation
198
Dysmegakaryopoiesis
Abnormal megakaryocyte or thrombocyte maturation
199
Eosinophilic hyperplasia
Eosinophilia in bone marrow and peripheral blood
200
Erythroid hyperplasia
Normal or increased cellularity with a normal or increased absolute neutrophil count and a low M:E ratio
201
Erythroid hypoplasia
Normal or decreased cellularity with a normal or decreased absolute neutrophil count and a high M:E ratio
202
Granulocytic hyperplasia
Normal or increased cellularity with a normal or increased PCV and a high M:E ratio
203
Hyperostosis
Thickening of cortical bone
204
Megakaryocyte emperipolesis
Presence of intact, viable blood cells within the cytoplasm of megakaryocytes
205
Megakaryocytic hyperplasia
Increase in numbers of megakaryocytes in bone marrow
206
Monocytic hyperplasia
Increased presence of precursor cells of the monocyte series
207
Myelodysplasia
Atypical cells with less than 30% blast cells present
208
Myelofribrosis
Increased presence of fibrous tissue that displaces hematopoietic tissue
209
Neoplasia
Atypical cells with more than 30% blast cells present
210
Neutrophilic hyperplasia, effective
Neutrophilia in bone marrow concurrent with neutropenia in peripheral blood
211
Neutrophilic hyperplasia, ineffective
Neutrophilia in bone marrow concurrent with neutropenia in peripheral blood
212
Osteosclerosis
Thickening of trabecular bone
213
Reactive macrophage hyperplasia
Increased presence of active macrophages often containing phagocytized material
214
Describe the procedures for the evaluation of bone marrow samples
Use a systemic approach and evaluate for overall cellularity
M:E ratio
Presence or absence of hemosiderin
The number of megakaryocytes present
Morphologic abnormalities
215
List the classification of anemia according to erythrocyte indices
Normocytic normochromic
Macrocytic hypochromic
Macrocytic normochromic
Microcytic normochromic/hypochromic
216
List the classification of anemia according to etiology
Hemolytic
Hemorrhagic
Iron deficiency
Production disorders
217
D-dimers
A protein fragment that is formed from the breakdown of fibrin
218
Fibrin degradation products
Protein fragments formed from the breakdown of fibrin
219
Microparticles
220
Phosphatidylserine
221
Thrombin
An enzyme that is formed from prothrombin, calcium, and thromboplastin in plasma during the clotting process
Causes fibrinogen to change to fibrin which is essential during the formation of a clot
222
von Willebrand disease
An inherited disorder that is characterized by the abnormally slow coagulation of the blood as well as spontaneous epistaxis and gingivitis bleeding
Caused by a deficiency of a component of factor VIII
Excessive bleeding is common after injury or surgery
223
Explain the classical view of hemostasis
The ability of the body's systems to maintain the integrity of the blood and blood vessels
224
Describe the cell-based model of hemostasis
225
Explain the role of platelets in the initiation of coagulation.
Platelets are attracted to the charged surface of the subendothelium of a ruptured blood vessel
The platelets adhere to each other and the endothelium
Activated platelets expose phospatidylserine on their outer membrane
226
Describe the role of von Willebrand factor in blood coagulation
Stabilizes the platelet plug
227
Discuss the formation of coagulation complexes.
228
Describe the role of thrombin in hemostasis
Continued to recruit and activate more platelets and triggers the conversion of fibrinogen to fibrin
229
Discuss the formation of fibrin degradation products and D-dimers.
The clot undergoes dissolution
As it breaks down, D-dimers and fibrin degradation products are released
230
Fibrometer
An instrument used for the hemostatic evaluation of samples
231
Hypercoagulable
Characterized by abnormally increased coagulability
232
Hypocoagulable
Characterized by abnormally decreased coagulability
233
Monovette
a sterile glass or plastic test tube with a colored rubber stopper creating a vacuum seal inside of the tube, facilitating the drawing of a predetermined volume of liquid
234
Thromboelastography
shows the interaction of platelets with the coagulation cascade (aggregation, clot strengthening, fibrin cross-linking and fibrinolysis)
235
Describe the proper sample collection procedures for coagulation testing.
Use careful techniques to minimize tissue damage and cause minimal venous stasis
Never use an indwelling catheter
Use a Vacutainer or Monovette
236
List the anticoagulants that are used for blood coagulation tests.
Sodium-citrate-anticoagulated plasma
EDTA-anticoagulated
237
Describe the method used to determine the proper ratio of blood to citrate anticoagulant.
1 part citrate to 9 parts whole blood
Calculate with the equation:
Volume of citrate required = 0.00185 x Blood volume to be collected x (100-Hematocrit [%])
238
Discuss proper sample handling of samples for coagulation testing.
The sample should be labeled and transported rapidly to the lab
Tubes should be held at room temp, remain tightly capped, and be kept upright
Tests should be performed within 2 hours of collection
Sample can be centrifuged and then the collected plasma is frozen in a plastic tube
239
Describe the instrumentation available for coagulation testing in vet practices and referral labs.
Coag Dx Analyzer
Fibrometer
Thromboelastograph
Platelet function analyzers
Point-of-care analyzers
240
Mean platelet volume
Mathematical average of the size of the individual platelets counted by the analyzer
241
Platelet distribution width
Assess the variation in the size of platelets
242
Platelet-large cell ratio
a percentage of all platelets with a volume measuring over 12 fL circulating in the bloodstream
243
Plateletcrit
the volume occupied by platelets in the blood as a percentage and calculated according to the formula PCT = platelet count × MPV / 10,000 (25-27)
244
Thrombocrit
Measure of the percentage of the total blood volume that is comprised of platelets
245
Thrombocytopenia
Decreased platelets
246
Thrombocytosis
Increased platelets
247
Thrombopathia
A condition in which there is a deficiency of clotting ability for reasons other than thrombocytopenia
248
Describe methods for the counting of platelets
Automated hematology analyzers
Manual counting with a hemacytometer
249
Describe platelet estimation methods
Use a differential blood film and count the number of platelets in 10 fields, then multiply the average number by 15,000 or 20,000
Or
Count the number of platelets per 100 WBCs on a film then calculate using the equation:
Thrombocytes x WBC count/100 leukocytes = thrombocytes/mL
250
List and describe the platelet indices.
Mean platelet volume (MPV)
Plateletcrit or thrombocrit
251
Activated clotting time
A test of the intrinsic and common pathways of blood coagulation that involves the use of diatomaceous earth or kaolin tube to initiate clotting
252
Activated partial thromboplastin time
A test of intrinsic and common coagulation pathways
An intrinsic pathways activator is added to plasma and the time taken for clot formation is measured
253
Buccal mucosa bleeding time
A test that uses a standardized shallow incision into the buccal mucosa of the upper lip to evaluate primary hemostasis
254
Clot retraction
A crude but simple test that allows for the evaluation of platelet number and function and intrinsic and extrinsic pathways
255
PIVKA
Proteins induced by vitamin K deficiency or antagonists
The nonfunctional precursor forms of vitamin-K-dependent coagulation factors
256
Prothrombin time tests
A one-stage test for detecting certain plasma coagulation defects that are caused by deficiency of factors V, VII, or X
257
Describe the procedure for performing the buccal.mucosa bleeding time test
Tie the upper lip back with a gauze to help act as a tourniquet
Make a 1-mm-deep incision
Blot the incision sure every 5 seconds until bleeding has stopped
Normal is 1 to 5 mins
258
Describe the procedure for performing the activated clotting time test
Prewarm the vacutainer to 37° C
Collect 2mL via venipuncture
Timed from collection to presence of clot
Normal is 60 to 90 seconds
259
Describe the principles of the activated partial thromboplastin time test and the prothrombin time test (aPTT and PTT)
It evaluates the intrinsic pathway and requires several reagents
260
Describe the procedure for performing the heat precipitation fibrinogen test
2 hematocrit tubes are centrifuged
The total solids in one tube are then determined with a refractometer
The second tube is incubated at 58°C for 3 minutes, then recentrifuged, and the total solids are measured
261
Disseminated intravascular coagulation
An acquired secondary coagulation disorder that is characterized by the depletion of thrombocytes and coagulation factors
262
Hemophilia
A genetic abnormality of hemostasis that results in many tissues, especially the liver and lungs, and that has potent anticoagulant properties
263
von Willebrand factor
a blood glycoprotein involved in hemostasis, specifically, platelet adhesion
264
Describe the types of hemostatic disorders seen in veterinary species.
Primary coagulation disorders or secondary coagulation disorders
265
Differentiate between hereditary and acquired defects of hemostasis
266
List and describe the common clinical signs of hemostatic disorders
Superficial petechia
Ecchymotic hemorrhage
Epistaxis
Melena
Prolonged bleeding
267
List the common inherited disorders of coagulation and the species and breeds usually affected
Prothrombin deficiency - cocker spaniel, beagle
Factor VII deficiency - beagle, malamute
Factor VIII deficiency - many breeds
Factor IX deficiency - many breeds
Factor X deficiency - cocker spaniel
Factor XI deficiency - great Pyrenees, English springer spaniel
Factor XII deficiency - poodle, shar pei
268
Describe the mechanisms involved in disseminated intravascular coagulation (DIC)
Consumptive coagulopathy that occurs secondary to other disease conditions
May manifests as systemic hemorrhage or microvascular thrombosis
Microthrombi result in tissue hypoxia, which consumes platelets and coagulation factors, which leads to an increased tendency for hemorrhage
Fibroblasts of the microthrombi leads to the formation of excess fibrin degradation products and D-dimers
