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201 Cards in this Set
- Front
- Back
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Why should you evaluate red cell morphology? |
Can be an indicator of anemia or other disease states |
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What is the cause of hypochromia? |
Decrease in hemoglobin concentration |
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What is the cause of polychromatophilia? |
Residual RNA in red blood cells |
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What is anisocytosis? |
Variation in size |
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What is poikilocytosis? |
Variation in shape |
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What causes poikilocytosis? |
Change in red cell membrane Abnormal metabolic state Abnormal hemoglobin Abnormal microenvironment RBC age |
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In what condition will you see ovalocytes? |
Megaloblastic anemias |
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In what condition will you see elliptocytes? |
Iron deficiency anemia Megaloblastic anemia Hereditary elliptocytosis |
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What causes red cells to become elliptocytes? |
Cytoskeleton defects |
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In what conditions will you see spherocytes? |
Hereditary spherocytosis Immune hemolytic anemia |
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In what conditions will you see target cells? |
Liver disease Abnormal hemoglobin |
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What causes red cells to become stomatocytes? |
Membrane defect due to increased sodium permeability |
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In what conditions will you see stomatocytes? |
Hereditary stomatocytosis Liver disease Alcoholism Electrolyte imbalance |
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What causes red cells to become acanthocytes? |
Due to change in plasma lipids |
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In what conditions will you see acanthocytes? |
Alcoholism Malabsorption Lipid metabolism disorders |
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In what conditions will you see echinocytes? |
Uremia Acute blood loss Stomach cancer |
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What causes red cells to become schistocytes? |
Physical damage to RBC membrane |
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In what conditions will teardrop cells be seen? |
Pernicious anemia Beta thalassemia Tuberculosis |
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What causes red cells to become teardrop cells? |
Presence of an inclusion Inability to regain shape after squeezing through small spaces |
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What causes red cells to become pyropoikilocytosis? |
Thermal damage Heat sensitivity Abnormal spectrin in membrane |
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In what conditions will you see pyropoikilocytes? |
Pyropoikilocytosis |
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What causes red cells to become sickle cells? |
Abnormal hemoglobin S |
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In what conditions will you see sickle cells? |
Sickle cell anemia Hgb SC disease Hgb S thalassemia |
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What causes basophilic stippling in red cells? |
Ribosomal aggregates |
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In what conditions will basophilic stippling be seen? |
Lead poisoning Alcoholism Megaloblastic anemia |
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What causes Howell-Jolly bodies in red cells? |
Nuclear remnants of DNA |
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What is the most common inclusion showing accelerated erythopoiesis? |
Basophilic stippling |
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In what conditions will HJ bodies be seen? |
Megaloblastic anemia Hemolytic anemia Splenectomy |
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What causes Pappenheimer bodies in red cells? |
Iron deposits |
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In what conditions will Pappenheimer bodies be seen? |
Sideroblastic anemia Hemoglobinopathies Splenectomy |
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What is the confirmatory test for the presence of Pappenheimer bodies? |
Prussian blue stain |
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What stain is used to identify Heinz bodies? |
Supravital stain |
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What causes Heinz bodies to form in red cells? |
Denatured hemoglobin |
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In what conditions are Heinz bodies seen? |
G6PD deficiency Toxic poisoning |
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What causes Cabot rings to be formed in red cells? |
Remnants of microtubules or mitotic spindle |
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In what conditions will Cabot rings be seen? |
Megaloblastic anemia Lead poisoning |
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What causes rouleaux? |
High levels of plasma proteins or abnormal proteins |
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What type of stain is used to identify hemoglobin H? |
Supravital stain |
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What is anemia? |
Inability of blood to apply tissues with oxygen |
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What does hematemasis mean? |
Vomiting blood |
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What does melena mean? |
Black stool |
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What does hematochezia mean? |
Red blood in feces |
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What does hemoptysis mean? |
Coughing up blood |
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What does epistaxis mean? |
Nosebleed |
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What are the non specific signs of anemia? |
Fatigue Nausea Constipation Diarrhea Dyspnea Severe pallor Smooth tongue |
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What is the most common cause of anemia? |
Iron deficiency |
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What is the primary function of iron? |
Oxygen transport |
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What are the sites of iron in the body? |
Hemoglobin Bone marrow Liver Spleen |
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How much of iron is formed in hemoglobin? |
2/3 |
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What is the function of transferrin? |
To bind and transport iron |
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What is the function of hemosiderin? |
Store iron during RBC degradation |
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Where is hemosiderin found? |
Macrophages |
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What is the most frequently requested test to aid in the diagnosis of IDA? |
Iron assay |
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What is the principle of the iron assay? |
Measures iron bound to transferrin |
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What is the principle of the TIBC assay? |
Measures the amount of iron that could be bound to transferrin |
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What test is the indicator of a patient's iron storage levels? |
Ferritin |
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What is the first test to become abnormal when iron stores are depleted? |
Ferritin |
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What are the clinical manifestations of IDA? |
Weakness Koilonychia Cheilitis Glossitis Pica |
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What are sideroblastic anemias? |
Anemias of abnormal iron metabolism |
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What causes sideroblastic anemias? |
Defective iron reutilization Improper incorporation of iron |
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What conditions may result from defective iron utilization? |
Hemosiderosis Hemochromatosis Hereditary sideroblastic anemia |
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What is hemosiderosis? |
Accumulation of excess iron in macrophages |
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What are megaloblastic anemias? |
Group of dissidents characterized by defective nuclear maturation due to impaired DNA synthesis |
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What are the clinical manifestations of megaloblastic anemias? |
Weakness Fatigue Congestive heart failure Jaundice Pallor |
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What is the major cause of vitamin B12 deficiency? |
Malabsorption of vitamin B12 |
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What is the most common cause of folate deficiency? |
Decreased dietary intake |
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Where does optimal absorption of iron occur? |
Small intestine |
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Excess iron is stored in what forms? |
As ferritin or hemosiderin |
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What is the principle of the transferrin saturation percentage? |
Measurement of the maximum amount of iron that is bound in serum |
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Transferrin saturation below what percentage is indicative of iron deficiency? |
<16% |
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What are the CBC results of IDA? |
Decreased H&H MCV 55-74 fL MCH 14-26 pg MCHC 22-31 g/dL Increases RDW |
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How does the PBS of IDA appear? |
Microcytic Hypochromic |
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What is hemochromatosis? |
Accumulation of excess iron in tissues due to increase absorption |
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Where does the excess iron deposit in hemosiderosis? |
RES |
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Where does the excess iron deposit in hemochromatosis? |
Liver Pancreas Spleen Heart |
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What condition is associated with bronze diabetes? |
Hemochromatosis |
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What is the treatment for IDA? |
Iron supplements Intravenous iron Transfusion for severe cases |
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What is the treatment for sideroblastic anemias? |
Therapeutic phlebotomy Chelating agents Discontinuation of medications |
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What is the cause of hereditary sideroblastic anemia? |
Detective heme synthesis |
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What are porphyrias? |
Accumulation of porphyrin due to defective heme synthesis |
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What is the result of porphyria? |
Decreased hemoglobin production |
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What type of porphyria is characterized by accumulation in the liver? |
Hepatic porphyria |
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What type of porphyria is characterized by accumulation in the bone marrow? |
Erythropoietic porphyria |
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What effects does erythropoietic porphyria have? |
Photosensitivity |
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What effects does hepatic porphyria have? |
Neurological disorders |
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What are the iron studies results in IDA? |
Iron: Decreased Ferritin: Decreased TIBC: Increased Saturation: Decreased |
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What are the iron studies results in sideroblastic anemia? |
Iron: Increased Ferritin: Increased TIBC: Normal/Decreased Saturation: Increased |
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The average adult has a total body iron content of? |
3500 mg |
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What percent of ingested iron is absorbed? |
5-10% |
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The hypochromic anemias represent a related group of disorder with? |
Quantitative defect in hemoglobin synthesis |
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Older patients often develop IDA because of? |
GI bleed |
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Microcytosis of red cells is reflected by? |
Decreased MCV |
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What is a common feature of sideroblastic anemias? |
Ringed sideroblasts |
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What is the most sensitive assay to screen for hemochromatosis? |
Transferrin saturation |
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When does iron deficiency occur? |
Inadequate iron intake Excess iron loss Increase need for iron |
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What is the minimum daily requirement for iron? |
1 mg/day |
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What characteristic cells are present in megaloblastic anemias? |
Megaloblasts Macro-ovalocytes |
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What biochemical finding causes the megaloblastic morphology? |
Decrease in thymidine triphosphate synthesis |
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How does thymidine deficiency affect nuclear development? |
Interferes with maturation, DNA replication, and cell division |
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What are the primary causes for the lack of thymidine? |
Vitamin B12 deficiency Folate deficiency |
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What is the CBC findings of megaloblastic anemias? |
RBC: Decreased HGB: Normal/decreased MCV: 100-160 fL MCH: Increased MCHC: Normal |
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How will the PBS appear in megaloblastic anemia? |
Macrocytic Normochromic |
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What inclusions are seen in megaloblastic anemia? |
HJ bodies Basophilic stippling Cabot rings Nucleated RBC's Hypersegmented neutrophils |
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How long does the vitamin B12 stores last? |
3-6 years |
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Vitamin B12 is absorbed at which site in the body? |
Ileum Small intestine |
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What is the function of vitamin B12? |
Cofactor of enzymatic reactions in DNA synthesis |
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What two proteins are required for vitamin B12 transport? |
Intrinsic factor Transcobalamin II |
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What tissue secretes intrinsic factor? |
Parietal cells of the stomach |
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What is the main transport protein of vitamin B12 to the tissues? |
Transcobalamin II |
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What is the function of intrinsic factor? |
Binds to vitamin B12 to be absorbed by the intestines |
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What is the most common form of vitamin B12 malabsorption? |
Pernicious anemia |
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What is pernicious anemia? |
Defective cobalamin absorption due to lack of intrinsic factor |
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What causes pernicious anemia? |
Gastric parietal cell atrophy |
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What are the clinical manifestations of pernicious anemia? |
Glossitis Loss of appetite Megaloblastic madness |
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Folate is absorbed at what site in the body? |
Small intestine |
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What is the function of folate? |
Cofactor of enzymatic reaction in DNA synthesis |
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What is the purpose of the Schilling test? |
Differentiates between vitamin B12 deficiency and pernicious anemia |
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What is the pathophysiology of megaloblastic anemias? |
Defective DNA synthesis and abnormal nuclear maturation |
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What is aplastic anemia? |
Bone marrow failure and loss of cellularity leading to pancytopenia |
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What is the most common cause of aplastic anemia? |
Idiopathic or unknown |
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What is characteristic of drug induced aplastic anemia? |
Toxicity is not related to dosage |
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How does higher doses of radiation contribute to aplastic anemia? |
Complete loss of all hematopoietic cells |
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How does lower doses of radiation contribute to aplastic anemia? |
Reversible pancytopenia |
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How does ionizing radiation affect bone marrow? |
Disrupts chemical bonds by forming free radicals that causes breaks to DNA |
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What types of viral infections are associated with aplastic anemia? |
Hepatitis EBV Cytomegalovirus HIV-1 |
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How can infections contribute to aplastic anemia? |
Immune destruction of bone marrow |
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What are the clinical manifestations of aplastic anemia? |
Fatigue Dyspnea Pallor Infection |
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What are the hematological findings of aplastic anemia? |
CBC: Pancytopenia PBS: N/N RETIC: Decreased DIFF: Lymphocytosis BM: Hypocellular |
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What is the congenital form of aplastic anemia? |
Fanconi's anemia |
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What is the congenital form of pure red cell aplasia? |
Diamond-Blackfan anemia |
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What is pure red cell aplasia? |
Loss of bone marrow red cell precursors |
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What are the hematological findings of pure red cell aplasia? |
PBS: N/N RETIC: Decreased DIFF: Normal WBC/PLT BM: Absent RBC precursors EPO: Increased |
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What are hemolytic anemias? |
Conditions of increased RBC destruction with inadequate BM response |
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What tests reflect Increased RBC destruction? |
Increased indirect bilirubin Decreased haptoglobin |
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What test reflects Increased RBC production? |
Increased retic |
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How does the Coomb's test reflect hemolysis? |
Used to detect autoimmune hemolytic anemia |
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Which hemolytic anemias are due to membrane defects? |
Hereditary spherocytosis Hereditary elliptocytosis Hereditary pyropoikilocytosis |
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What causes hereditary spherocytosis? |
Spectrin deficiency |
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What are the clinical manifestations of hereditary spherocytosis? |
Anemia Jaundice Splenomegaly Skeletal abnormalities |
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What are the lab findings of hereditary spherocytosis? |
Increased indirect bilirubin Decreased haptoglobin Decreased hemoglobin PBS: N/N MCHC: Increased |
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What specialized testing is used to help diagnosis hereditary spherocytosis? |
Osmotic fragility test |
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What causes hereditary elliptocytosis? |
Altered spectrin or protein 4.1 deficiency |
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What causes hereditary pyropoikilocytosis? |
Quantitative decrease and structural abnormality of spectrin |
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What test is used to detect hereditary pyropoikilocytosis? |
Thermal sensitivity |
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What causes hereditary stomatocytosis? |
Alterations in permeability of the RBC membrane to cations |
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What effect does stomatocytosis have on the red cells? |
Sodium and water moves into the cell while potassium moves out |
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What are the lab findings of stomatocytosis? |
MCV: Increased MCHC: Decreased Increased osmotic fragility |
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What are hemoglobinopathies? |
Condition of abnormal hemoglobin synthesis |
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Genes for beta, delta, and gamma globin chains are located on which chromosome? |
Chromosome 11 |
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Genes for alpha and zeta globin chains are located on which chromosome? |
Chromosome 16 |
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The majority of hemoglobinopathies involve which chain? |
Beta chain substitutions |
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Hemoglobin S results from what beta chain substitution? |
Valine replaces glutamic acid |
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Hemoglobin C results from what beta chain variant? |
Lysine replaces glutamic acid |
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What are the normal hemoglobins? |
Hgb A Hgb A2 Hgb F |
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What assembly constitutes Hgb A? |
2 alpha chains 2 beta chains |
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What assembly constitutes Hgb A2? |
2 alpha chains 2 delta chains |
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What assembly constitutes Hgb F? |
2 alpha chains 2 gamma chains |
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What cause red cells to sickle? |
Decrease in oxygen, pH or dehydration |
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What is sickle cell disease? |
Genetic disorder characterized by the production of Hgb S |
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What test are performed to diagnose sickle cell? |
CBC/PBS Retic Sickle solubility test Hgb electrophoresis |
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What screening test is used to detect Hgb S? |
Sickle solubility test |
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Which hemoglobin will yield positive results for the solubility test? |
Hgb SS Hgb AS Hgb Barts Hgb S thalassemia |
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How do you differentiate Hgb A2/c on electrophoresis? |
Use an acidic agar |
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What is the only clinically significant alpha chain variant for hemoglobin? |
Hgb G - Philadelphia |
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Hgb G-Philadelphia results from what alpha chain variant? |
Lysine replaces asparagine |
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What are unstable hemoglobins? |
Variants in which substitutions or deletions have weakened the binding forces that maintain the molecular structure |
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What is the cause of thalassemia? |
Decreased synthesis of globin chains |
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What are thalassemias? |
Anemias of abnormal globin synthesis |
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What is beta thalassemia major? |
Absence of beta chain production |
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What is beta thalassemia minor? |
Reduced amount of beta chains |
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Beta thalassemia has increased levels of which hemoglobin? |
Hgb F Hgb A2 |
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What causes Hgb Barts/alpha thalassemia? |
Absence of alpha chains |
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What causes Hgb H/alpha thalassemia? |
Only one functioning alpha gene |
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What assembly constitutes Hgb Barts? |
4 gamma chains |
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What assembly constitutes Hgb H? |
4 beta chains |
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What causes alpha thalassemia minor? |
Defects in 2 of 4 alpha globin chains |
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What causes the silent carrier alpha thalassemia? |
One defective alpha globin chain of four |
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What effect does Hgb Barts have? |
Incapable of oxygen transport to tissues |
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What is the most common RBC enzymopathy associated with hemolysis? |
G6PD deficiency |
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What is G6PD? |
Enzyme necessary for completion of hexose monophosphate shunt |
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What is paroxysmal nocturnal hemoglobinuria? |
Acquired hemolytic anemia associated with cellular membrane abnormalities |
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What causes PNH? |
Lack of certain surface proteins that leads to increased sensitivity to lysis by complement |
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How does sleep induce hemolysis in PNH? |
CO2 retention and decrease in pH leads to increased complement activation |
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What is the screening test for PNH? |
Sucrose hemolysis test |
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What is the confirmatory test for PNH? |
Ham's test |
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What is the principle of the sucrose hemolysis test? |
Sucrose promotes complement binds to RBC leading to hemolysis |
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What is the principle of Ham's test? |
Acidic pH causes complement activation and hemolysis of RBC |
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What is the most common cause of death for PNH? |
Thromboembolism |
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What is the most commonly accepted method for measuring hemoglobin? |
Conversion of hemoglobin to cyanmethemoglobin followed by spectrophotometry |
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What is the purpose of the MCV? |
Used as an estimation of the average size of red cells |
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What is the purpose of the MCH? |
Measure of hemoglobin content |
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What is the function of spectrin? |
Major role in cell membrane integrity |
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Zeta globin chain mature to what form? |
Alpha chains |
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Epsilon globin chains mature to what form? |
Beta Delta Gamma |
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Where does the initial and final phases of heme synthesis occur? |
Mitochondria |
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Where does the intermediate phase of heme synthesis occur? |
Cytoplasm |
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What percentage of adult hemoglobin is Hgb A? |
96-97% |
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What percentage of adult hemoglobin is Hgb A2? |
2-3% |
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What percentage of adult hemoglobin is Hgb F? |
<1% |
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What are the nonfunctional forms of hemoglobin? |
Methemoglobin Sulfhemoglobin Carboxyhemoglobin |
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What effect does methemoglobin have? |
Cyanosis |
