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VMD434 Hematology Midterm
Midterm review
71
Veterinary Medicine
Professional
05/15/2011

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Cards

Term
What is the usual process by which routinely used coagulants work?
Definition
EDTA and citrate chelate calcium while heparin activates antithrombin II
Term
What is the difference between blood cells in birds and in mammals?
Definition
Mammals have anucleate RBCs and anucleate platelets, while birds have nucleated RBCs and nucleated thrombocytes
Term
What are heterophils? What species have them?
Definition
Leukocytes that stain similar to eosinophils but function as neutrophils.
Guinea pigs, birds,
Term
Where does erythropoeisis take place?
Definition
Erythropoeitic islands in the bone marrow
Term
In healthy reptiles ____________ are the most common blood cells and _____________ are second most common.
Definition
Erythrocytes, thrombocytes
Term
Neutrophils are the predominant WBC type in all domestic animals EXCEPT which one?
Definition
Sheep
(Neutrophils are predominant in horses, cats, dogs and pigs)
Term
What cells are present in the buffy coat of a centrifuged anticoagulated blood sample?
Definition
Platelets and leukocytes
Term
What cells comprise the maturative pool of erythrocytes? The proliferative pool?
Definition
Maturative: polychromic rubricytes, metarubricytes and polychromic erythrocytes.
Proliferative: rubriblasts, prorubricytes, basophilic rubricytes
Term
What cells comprise the maturative pool of granulocytes? The proliferative pool?
Definition
Maturative: metamyelocytes, band cells
Proliferative: myeloblasts, promyelocytes, myelocytes
Term
Which is larger, the proliferative or maturative pool of erythroid cells?
Definition
Proliferative
Term
Which have a higher nucleus to cytoplasmic ratio, proliferative or maturative erythroid cells?
Definition
Proliferative (high N:C vs maturative, medium to low N:C)
Term
Which erythroid pool of cells has the deeper blue-staining cytoplasm?
Definition
Proliferative pool
Term
What is the structure of hemoglobin?
Definition
2 globin chains of one type, 2 globin chains of another type, 4 iron molecules, 4 protoporphyrin rings
Term
What is the FUNDAMENTAL stimulus for erythropoeisis?
Definition
Hypoxia
Term
What is the fate of hemoglobin IRON in adult mammals?
Definition
Iron stored in macrophages until released into blood bound to transferrin, transported to bone marrow and re-used to form hemoglobin by developing erythropoetic cells
Term
What is the major fate of catabolized hemoglobin porphyrin rings in adult mammals?
Definition
Porphyrin ring converted to bilirubin in macrophages. Bilirubin released into blood bound to albumin, transported to liver where taken up and conjugated to glucoronic acid. Transported to bile ducts and emptied into intestinal tracts.
Term
What are the products of excessive oxidation of erythrocyte components?
Definition
Heinz bodies and methemoglobin
Term
Normal hemoglobin has iron bound in which state, ferrous or ferric?
Definition
Ferrous state, Fe+2
Term
What is methemoglobin?
Definition
Hemoglobin bound to iron in ferric Fe+3 state
Term
Congenital erythropoeitic porphyria (CEP)results in anemia because of what defect?
Definition
Heme synthesis
Term
What metabolite MOST influences oxygen-hemoglobin binding and O2 release from hemoglobin in most mammals?
Definition
2,3 DPG
Term
What metabolite is MOST important for prevention of Heinz body formation?
Definition
NADPH
Term
What are Heinz bodies? What is the primary cause of Heinz body formation in domestic animals?
Definition
Aggregates of denatured hemoglobin.
Toxic drugs and plants (onions)
Term
What pathway is responsible for NADPH production in erythrocytes?
Definition
Pentose Phosphate Pathway (PPP)
Term
What metabolic pathway is MOST responsible for producing metabolites that prevent/inhibit excessive methemoglobin production? What is this metabolite?
Definition
Embden-Meyerhof pathway/glycolysis
NADH, secondarily NADPH
Term
What is the "pitting function" of the spleen? Why do cats have higher numbers of Heinz bodies?
Definition
Heinz body containing RBCs are removed by splenic macrophages. Cats have NON-sinusoidal spleens so pitting function is limited
Term
What characteristics are commonly present in the CBC of animals with iron deficiency?
Definition
Decreased MCV and decreased MCHC
Term
What are the correct terms to describe erythrocytes produced in iron deficiency?
Definition
Hypochromic and microcytic
Term
What are polychromatophilic erythrocytes?
Definition
Young erythrocytes with diffuse gray-blue cytoplasm in Wright's stained smears
Term
What regulates body iron, rate of absorption or rate of excretion?
Definition
Rate of ABSORPTION
Term
Large iron stores ____________ absorption while increased erythropoiesis _____________ iron absorption.
Definition
decrease, increases
Term
What molecule is MOST important in regulating plasma iron levels
Definition
Hepcidin
Term
What are the three types of granulocytes in mammals?
Definition
Neutrophils, eosinophils, basophils
Term
Neutrophils are the predominant leukocyte in the peripheral blood of all major domestic species except what species? What is that species' predominant leukocyte?
Definition
Cows, lymphocytes
Term
What cell types are found only in the granulocyte maturative/storage pools of the bone marrow?
Definition
Metamyelocytes, banded neutrophils, segmented neutrophils
Term
True or False?
Hematopoiesis includes decreasing cell and nuclear size and increasing cytoplasmic basophilia with maturation.
Definition
True
Term
True or False?
The megakaryocytic lineage gets smaller with maturation.
Definition
False
Term
Erythrocyte cytoskeletal proteins include what 4 proteins?
Definition
Spectrin, ankyrin, actin, protein 4.1
Term
The heme moiety of hemoglobin is a complex multiple ring structure consisting of protoporphyrin coupled to iron. Lead inhibits several enzymes involved in heme synthesis and results in the accumulation of several intermediates in this pathway. Two important intermediates are what?
Definition
ALA, protoporphyrin IX
Term
By what mechanism does iron deficiency result in erythrocyte microcytosis?
Definition
Iron deficiency results in additional divisions of erythroid precursors in bone marrow --> microcytic and hypochromic
Term
True or false?
When an erythrocyte is removed from the blood by the mononuclear phagocytic system, it’s hemoglobin is catabolized.
Definition
True
Term
What metabolic products are required for prevention of oxidative damage to erythrocyte components?
Definition
NADPH, NADH, GSH
Term
Which metabolic product is most physiologically important for reduction of methemoglobin to oxyhemoglobin (in normal physiological states)?
Definition
NADH
Term
What is the most common RBC enzyme deficiency?
Definition
PK deficiency - impairs ATP production, shortened RBC lifespan --> regenerative anemia but eventually develop marrow failure [basenjis, beagles, Westies]
Term
What happens in PFK deficiency?
Definition
decreased RBC 2,3 DPG concentration and hemolysis after alkalosis (ie exercise)
[English Springers, cocker spaniels]
Term
What are the four metabolic pahtways in mature RBCs?
Definition
1) Embden-Meyerhof (glycoolytic)
2) Pentose phosphate pathway (PPP)
3) Methemoglobin reductase pathway
4) Rapoport-Luebering pathway
Term
What is the effect of lead poisoning?
Definition
ALA-D is the enzyme involved in the second step of heme synthesis, synthesis of PBG (porphobilinogen). Lead INHIBITS this step, so ALA accumulation and mild anemia. Lead also inhibits the FINAL step in heme formation cataluyzed by heme synthetase - in lead tox, protoporphyrin IX accumulates.
Term
What is a detection test for lead poisoning? Why?
Definition
Accumulation of protoporphyrin IX. Lead inhibits heme synthetase which convert protoporphyrin IX to heme
Term
What enzyme deficiency leads to congenital erythropoietic porphyria (CEP)?
Definition
Deficiency of UROgen III cosynthetase which catalyzes the step of Hgb to correct isomer. Results in photosensitivity, discolored teeth and urine, hemolytic anemia
Term
What is the control for heme synthesis? How is it controlled?
Definition
First step, enzyme delta-aminolevulinic acid synthetase. Synthesis of this enzyme is controlled by negative feedback from heme concentration within RBC (self-regulating)
Term
Approximately what weight of RBC is Hgb? Why is it advantageous for Hgb to be enclosed within a cell?
Definition
Packets of high O2 can be delivered to tissues, intracellular protects Hgb from oxidation and degradation (would otherwise degrade in minutes)
Term
What is thought to be the reason RBCs are biconcave?
Definition
Most efficient form for release and uptake of O2
Term
Aggregates of spectrin bind to actin and other proteins such as protein 4.1 to form ______ _______ that further bind the meshwork to integral membrane glycoproteins called __________.
Definition
Junctional complexes, glycophorins
Term
What is required for maintanence of shape and deformity of RBCS? How is this produced in RBCs?
Definition
ATP, Embden-Meyerhof (glycolytic) pathway
Term
What protein binds iron in epithelial cells? In the blood?
Definition
Ferritin, transferrin
Term
The rate of epithelial cell iron transfer varies _______ with body's iron stores, and _______ directly with the rate of erythropoiesis.
Definition
Inversely, directl
Term
What is the major signal that determines when RBCs are "done?"
Definition
Hemoglobin concentration
Term
How is iron stores in tissues?
Definition
As ferritin or converted to aggregates of ferritin called hemosiderin
Term
Clinically, how can we evaluate iron status?
Definition
Serum iron (iron bound to transferrin), total iron-binding concentration (transferrin concentration) or tissue hemosiderin
Term
What is the difference between indirect and direct bilirubin?
Definition
Indirect is unconjugated bilirubin, direct is conjugated
Term
33. Reticulocytes can be enumerated by staining blood with viral stain new methylene blue. What is the substance or structures detected in erythrocytes by this stain?
Definition
Aggregates of ribosomes
Term
What are the three layers of centrifuged anti-coagulated blood and what are the components of these layers?
Definition
1. (top) Plasma - proteins, electrolytes, fibrinogen
2. Buffy coat - leukocytes and platelets
3. RBCs
Term
What cells are produced from the myeloid lineage?
Definition
Erythrocytes, neutrophils/heterophils, eosinophils, basophils, monocytes, platelets
Term
What cells are produced from the lymphoid lineage?
Definition
Lymphocytes, B and T cells
Term
What is the difference in serum and plasma?
Definition
Serum is from blood that has been allowed to clot, so does NOT have fibrinogen or clotting factors. Plasma is from anticoagulated blood so still has clotting factors
Term
Explain why erythropoiesis and myelopoiesis in bone marrow of animals appear closely related while separate in birds.
Definition
Birds - erythropoiesis occurs in blind sinusoids and RBCS and thrombocytes don't need to cross endothelium to circulate, but myelopoiesis occurs EXTRAvascularly. Both myelo and hematopoiesis occur extravascularly in mammals.
Term
How can erythroid and myeloid proliferative pools be differentiated?
Definition
Erythroid pools are very basophilic
Term
How can proliferative myeloid cells be differentiated from maturative myeloid cells?
Definition
Nuclear morphology - proliferative = round, maturative become segmented and no longer round
Term
Does MCHC or MCV vary greatly between species?
Definition
MCV
Term
What is anisoocytosis?
Definition
Variation in size of RBCs (normal in goats, not normal on most species)
Term
On an erythrogram, what features would suggest response to anemia?
Definition
High reticulocyte count, increased MCV, decreased MCHC and increased RDW
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