1.3 Hematology Physiology - Function

Which of the following is NOT considered necessary for making a diagnosis of hereditary hemochromatosis (HH)? -Laboratory evidence of iron overload -Genetic mutations associated with HH -Clinical signs and symptoms consistent with HH -A positive family history

A positive family history (Having a positive family history is not considered necessary for making a diagnosis of hereditary hemochromatosis (HH). Laboratory evidence of iron overload, finding genetic mutations associated with HH, along with clinical signs and symptoms consistent with HH, are necessary for confirming a diagnosis of HH.)

The normal Myeloid-to-erythroid ratio (M:E ratio) ranges from: 2:1 to 7:1 1.2:1 to 5:1 2:1 to 4:1 0.5:1 to 1:1

2:1 to 4:1 (The M : E reference range is between 1.5:1 to 3:1. If segmented neutrophils are included, the M : E reference range is between 2:1 to 4:1.)

All of the following conditions are consistent with this peripheral blood picture, EXCEPT? Abetalipoproteinemia Alcoholic cirrhosis with hemolytic anemia Hepatitis of the newborn Post-splenectomy

Abetalipoproteinemia (The correct response is abetalipoproteinemia. While the majority of red blood cells in abetalipoproteinemia are acanthocytes, the peripheral blood smear that is pictured here contains only an occasional acanthocyte (the cell that is tagged by the arrow), an amount not consistent with abetalipoproteinemia. Acanthocytes in lesser numbers are found in advanced liver disease, in newborn hepatitis, and following splenectomy when there is reduced removal of these poikilocytes.)

What is the composition of the granules associated with basophilic Aggregates of iron Aggregates of hemoglobin Aggregates of ribosomes Aggregates of DNA

Aggregates of ribosomes (Basophilic stippling is composed of aggregates of ribosomes. Aggregates of iron within erythrocytes are called Pappenheimer bodies. Aggregates of hemoglobin are known as Heinz bodies, which require a supravital stain to observe. Aggregates of DNA found inside an erythrocyte are known as Howell-Jolly bodies.)

Basophils' primary role involves: Phagocytosis Allergic reactions Long term immunity Fighting parasitic infections

Allergic reactions (Basophils have a membrane receptor for IgE. When IgE attaches to this receptor, it causes the basophil to become activated and degranulate. As degranulation occurs, basophils release a series of granular components that orchestrate the allergic reaction. Neutrophils and macrophages are capable of phagocytosis, while lymphocytes are responsible for long-term immunity and eosinophils are capable of fighting helminth parasites.)

Which of the following globin genes are found on Chromosome 11? Beta, gamma, epsilon Beta, epsilon, alpha Gamma, epsilon, zeta Alpha, zeta

Beta, gamma, epsilon (The beta, gamma, and epsilon hemoglobin chain loci are found on chromosome 11. Alpha and zeta hemoglobin loci are found on chromosome 16. a2ß2), Adult hemoglobin roughly consists of 95% HbA(2A2B), 3% HbA2 (2A2D), and 2% HbF (2A2G).)

All of the following CD markers are present on a normal mature T cell, EXCEPT? CD20 CD7 CD3 CD5

CD20 (The CD20 marker is NOT present on mature T cells. CD20 is expressed by B cells. Normal mature T cells should express CD2, CD3, CD5 and CD7 markers.)

What are Howell-Jolly bodies composed of? a. Hemoglobin b. DNA c. Iron d. RNA

DNA (Howell-Jolly bodies are residual fragments of DNA within erythrocytes. They may be seen in pernicious anemia and thalassemias. RBC inclusions composed of precipitated hemoglobin are called Heinz bodies, seen on supravital stains. RBC inclusions composed of aggregates of iron are called Pappenheimer bodies. RBC inclusions composed of RNA are called basophilic stippling.)

Which of the following is NOT a way hemoglobinopathies can be caused? Deletion of a globin chain. Substitution of amino acids in a globin chain. Deletion of an amino acid in a globin chain. Addition of an amino acid in a globin chain.

Deletion of a globin chain. (Hemoglobinopathies are not caused by deletion of a globin chain. Partial and complete deletions of globin chains lead to thalassemia. Substitution of amino acids in a globin chain is the most common cause of hemoglobinopathies. Deletion or addition of an amino acid in a globin chain, or fusion of globin chains will also cause hemoglobinopathies.)

Which of the following represent other hemoglobin gene loci that occur on the same chromosome as the beta chain loci? Alpha and delta Delta and gamma Gamma and zeta Zeta and epsilon

Delta and gamma (The loci for globin chain production are found on Chromosomes 11 and 16. Alpha and zeta are both found on chromosome 16. Beta, delta, epsilon, and gamma are all found on chromosome 11. Genes for the production of alpha chains are found on chromosome 16, and genes for the production of delta chains are found on chromosome 11. Genes for the production of gamma chains are found on chromosome 16, and genes for the production of zeta chains are found on chromosome 11. Genes for the production of zeta chains are found on chromosome 11, and genes for epsilon chains are found on chromosome 16.)

Which of the following cellular function is correctly matched to the cell type? Eosinophil: Involved in some parasitic infection response RBC: Involved in immune response; especially viral Lymphocytes: Involved in hemostasis Platelet: Involved in bacterial infection response

Eosinophil: Involved in some parasitic infection response (Eosinophils: Involved in parasitic infection response; allergic response RBC: Involved in oxygen transport Lymphocytes: Involved in immune response; especially viral Platelets: Involved in hemostasis)

The bone marrow begins producing cells in the _____________ month of fetal life. First Fourth to Fifth Sixth Eighth

Fourth to Fifth (The bone marrow begins producing cells in the fourth to fifth month of fetal life is the correct answer. The liver begins producing cells in the first month, while the spleen produces cells in the second month. By the 6th month, hematopoiesis is in decline both in the spleen and the liver, and by the 8th month, the spleen is no longer an active site for hematopoiesis.)

Which of the following conditions would have macrocytic red cells? Liver disease and Vitamin B12 deficiency Iron deficiency and thalassemia Hereditary spherocytosis and hereditary elliptocytosis G6PD deficiency and malaria

G6PD deficiency and malaria (Chronic liver disease and Vitamin B12 deficiency would present with increased MCV and macrocytosis. Iron deficiency and thalassemia would present with decreased MCV and microcytosis. Hereditary spherocytosis and hereditary elliptocytosis would present with normal MCV and normocytic red cells. G6PD deficient patients and patients with malaria would have normal MCVs and normocytic red cells.)

Which of the following is a negative regulator of intestinal iron absorption? Hepcidin Ferroportin 1 Erythroferron Hephaestin

Hepcidin (Hepcidin is considered the "master iron-regulating" protein. It is a negative regulator meaning that as hepcidin levels rise, less iron is absorbed by the gut. In many cases of hereditary hemochromatosis, excess iron is absorbed by the gut due to low or absent levels of hepcidin. Ferroportin 1 is responsible for exporting cellular iron from RBCs. Erythroferron is an RBC regulator of hepcidin in response to erythropoietin. Hephaestin facilitates the cellular export of iron by ferroportin 1.)

The granules that basophils contain are composed of: Histamine Serotonin Myeloperoxidase Alkaline phosphatase

Histamine (Basophilic granules are composed of histamine. This characteristic is associated with increased basophils during allergic reactions. Serotonin is found in dense bodies in platelets. Myeloperoxidase is an enzyme found in myeloblasts. Alkaline phosphatase is an enzyme found in neutrophils.)

Which of the following major cellular elements does not develop solely in the bone marrow? Monocyte Neutrophil Lymphocyte Macrophage

Lymphocyte (Bone marrow is the site of myeloid, erythroid, and megakaryocyte as well as early stages of lymphoid cell development. From the major blood cells found in the peripheral blood, the lymphocytes may be produced not only in the bone marrow but also in lymphoid tissues. Bone marrow and thymus are considered primary lymphoid tissues: tissue in which lymphocytes from non-functional precursor cells develop and differentiate into immunocompetent lymphocytes. Spleen and lymph nodes are considered secondary lymphoid tissues in which T and B cells further divide and differentiate into effector and memory cells.)

Which of the following causes schistocyte formation in disseminated intravascular coagulation (DIC)? Degranulation of promyelocytes Excessive fever in patients with DIC Microthrombi disposition in small vessels Excessive platelet size

Microthrombi disposition in small vessels (Schistocytes are the result of erythrocytic membrane damage caused by sheering of red blood cells as they pass through a fibrin mesh of clot formation occurring in the blood vessels. This intravascular clot formation process occurs in DIC (disseminated intravascular coagulation), TTP (thrombotic thrombocytopenic purpura), and HUS (hemolytic uremic syndrome). Therefore, schistocytes may be seen in all three of these conditions. The primary granules of malignant promyelocytes in acute promyelocytic leukemia have procoagulant activity. Patients with acute promyelocytic leukemia may develop DIC. While the primary granules are responsible for initiating DIC in these patients, they are not directly responsible for schistocyte formation. While DIC may be preceded by septicemia or viremia, the fever itself is not responsible for schistocyte formation. Excessive platelet size is not directly relevant to schistocyte formation.)

All of the following are granulocytes EXCEPT: Neutrophilic band Basophil Mott cell Mast cell

Mott cell (Though they could almost appear granulated, Mott cells are plasma cells containing Russell's bodies (accumulation of immunoglobulins in the cytoplasm). Plasma cells are activated lymphocytes and thus are not granulocytes that derive from the myeloid lineage. Neutrophilic bands and basophils are granulocytes characterized by granules in the cytoplasm and mature from the myeloid stem cell. Though not found in the peripheral blood, mast cells are actually tissue basophils and contain potent granules in their cytoplasm.)

Eosinophilia is commonly found in which of the following disorder? Pernicious anemia Liver disease Parasitic infections Infectious mononucleosis

Parasitic infections (Eosinophilia is most commonly seen as a result of allergic reactions, medication reactions, and parasitic infections. Pernicious anemia is characterized by macrocytic erythrocytes (MCV>100). It is caused by an absence of intrinsic factor that leads to cobalamin deficiency. Liver disease leads to non-megaloblastic anemia. Hemolysis can occur and also impaired bone marrow response, folate deficiency and blood loss. Infectious mononucleosis is a viral infection characterized by a large percentage of reactive lymphocytes on the peripheral blood smear.)

Which of the following stages of neutrophilic granulocyte cellular development is at the second stage from the least mature stage? Band neutrophil Promyelocyte Metamyelocyte Myeloblast

Promyelocyte (The second stage of neutrophilic maturation is the promyelocyte stage. The correct sequence in the neutrophilic granulocyte maturation is myeloblast, promyelocyte, myelocyte, metamyelocyte, band (stab) neutrophil, segmented neutrophil. Band neutrophil is at the fifth stage of development. Metamyelocyte is at the fourth stage of development. Myeloblast is at the first stage of development.)

What is the correct order of erythrocyte maturaton in the bone marrow? (beginning from the most immature)

Pronormoblast, basophilic normoblast, polychromatophilic normoblast, orthochromic normoblast, polychromatophilic erythrocyte (Once the pluripotential stem cell differentiates into the myeloid stem cell, it can differentiate into an erythroblast. The subsequent stages listed are all identifiable on a bone marrow smear. Alternative nomenclature is: rubriblast, prorubricyte, rubricyte, metarubricyte, reticulocyte. The final stage is the mature erythrocyte. The other choices contain the correct names of the stages but they are incorrect order.)

Which potent inhibitor of platelet aggregation is released by endothelial cells? Epinephrine Prostacyclin Ristocetin Thromboxane A2

Prostacyclin Prostacyclin is produced by endothelial cells and prevents the formation of the platelet plug involved in primary hemostasis by preventing platelet activation and aggregation as well as inducing vasodilation. Epinephrine (agonist used in platelet aggregation studies), ristocetin (agonist used in platelet aggregation studies), and thromboxane A2 (platelet activator) are not produced by the endothelial cells.

The primary purpose of neutrophil granules is to: a. Facilitate nuclear maturation. b. Help distinguish neutrophils from lymphocytes. c. Prepare cells for removal from circulation. d. Provide microbicidal action.

Provide microbicidal action. (Neutrophils are a key component of the innate defense system. Neutrophil granules contain enzymes and other proteins that break down substrates, kill ingested bacteria, and secrete their contents during an inflammatory response. The granules do not have a role in nuclear maturation or in preparing cells for removal from circulation. While granules are a feature that helps distinguish neutrophils from lymphocytes, this is not their primary purpose.)

The bone marrow becomes the main site of hematopoiesis in the ________ month of gestation. The correct answer is highlighted belowFirst Second Fourth Seventh

Seventh (The correct answer is 7 months. The following is an outline of hematopoiesis: Hematopoiesis begins in the yolk sac and continues until about 2 months gestation. The fetal liver performs hematopoiesis from the second month until the seventh month. In addition, the spleen performs hematopoiesis from the third to the sixth month. The bone marrow begins hematopoiesis at approximately 7 months of gestation.)

Which of the following would best describe what you might observe after a traumatic CSF tap? All tubes pale yellow All tubes clear All tubes contain equal amounts of blood Significantly more RBCs were found in tube #1 vs. tube #3

Significantly more RBCs were found in tube #1 vs. tube #3 (A traumatic tap would result in more blood in the initial collection tube (#1) than in subsequent tubes (#2 and #3). Blood clots would also indicate a traumatic tap. If the sample is centrifuged within one hour of collection and the supernatant is pale yellow, the color in the CSF is not the result of a traumatic tap. This is xanthochromia which is caused by RBC degradation products due to previous subarachnoid hemorrhage.)

As an RBC ages, all of the following are true EXCEPT: The membrane becomes less flexible. The cellular hemoglobin concentration increases. Glycolysis and other enzyme activity decrease. They become less prone to phagocytosis.

They become less prone to phagocytosis. (The opposite is true. As the RBC ages, it becomes more susceptible to being phagocytized, most often in the spleen. As RBCs age, the following points are true: The membrane becomes less flexible. The concentration of cellular hemoglobin increases. Enzyme active diminishes, particularly glycolysis)

All of the following bones contain active hematopoietic bone marrow in a normal adult, EXCEPT? Pelvis Sternum Tibia Vertebrae

Tibia (The tibia contains active hematopoietic marrow only in children (before puberty). Blood cells are manufactured in the bone marrow of all bones in a child's body. A normal, healthy adult has active cell-forming bone marrow only in the central portion of the skeleton, including the pelvis, sternum, and vertebrae. Once they reach around the age of puberty, the long bones contain only inactive, yellow (fatty) marrow.)

To produce hemoglobin S (HbS), glutamic acid normally present in the sixth position on the beta-globin chain is substituted with which of the following? Cystine Guanine Thyamine Valine

Valine (Valine substitutes for glutamic acid in the Beta-6 position to produce HbS. This can be written as ß6(A3) Glu-->Val. In HbS, the mutation is in the ß-chain affecting the amino acid in the sixth position of the completed polypeptide located in the A3 helix position. HbS is altered hemoglobin found in sickle cell trait, sickle cell disease, and other hemoglobinopathies. In the deoxygenated state, HbS forms rigid aggregates that are insoluble. When this occurs, it reduces the stability of the hemoglobin molecule.)

The gene loci for the alpha-globin chains are adjacent to the locus for which other globin chain? Beta Delta Epsilon Zeta

Zeta (The order of globin gene loci on chromosome 16 is Zeta, Alpha 2, and Alpha 1. Beta globin gene, delta globin gene, and epsilon globin genes are found on chromosome 11.)

All of the following methods can be used to transport carbon dioxide to the lungs EXCEPT: Blood plasma Attached to neutrophils Bound to hemoglobin in the RBC In solution within the RBC

Attached to neutrophils (Neutrophils function in the immune response and do not play a role in carbon dioxide transport. Small quantities of carbon dioxide are transported in the blood plasma as bicarbonate. In the pulmonary capillaries, bicarbonate is converted back to carbon dioxide and eliminated through respiration. About one-fourth of the total carbon dioxide is transported to the lungs bound to hemoglobin (deoxyhemoglobin). The major transport mechanism for carbon dioxide (approximately three-fourths) is in solution as carbonic acid.)

All of the following are terms associated with segmented neutrophils EXCEPT? Poly Seg Macrophage PMN

Macrophage (The correct answer is the macrophage. A macrophage is associated with a monocyte that has migrated into the tissue, not a neutrophil. Poly, seg, and PMN are all terms that refer to segmented neutrophils. Poly is short for polymorphonuclear, as is PMN. Seg is short for segmented. Stab, while not an answer option, is another term used that refers to segmented neutrophils.)

Which statement best describes the relationship between dietary iron and iron absorption in a healthy individual? -Only a small percentage of dietary iron is absorbed and used. -All dietary iron is needed for hemoglobin synthesis and therefore absorbed. -Most people need to take dietary iron supplements to meet their needs for iron. -All dietary iron is absorbed and excess is stored.

Only a small percentage of dietary iron is absorbed and used. (Due to iron recycling, only a small percentage of dietary iron is absorbed and used. Also, the majority of dietary iron is in the ferric form, which is less easily absorbed than ferrous iron. As noted above, it is more difficult to absorb ferric iron, so even when the need is greater, it is unlikely that all would be absorbed. Healthy adults on normal diets do not typically need iron supplements. These would only be necessary in times of increased need, such as pregnancy, or due to blood loss. Excess iron would be stored, but once again, all iron is not absorbed.)

Regarding hemoglobin synthesis, which of the following constitutes the alpha globin chain coding? Two gene loci; one each on chromosome 11. Four gene loci; two each on chromosome 11. Two gene loci; one each on chromosome 16. Four gene loci; two each on chromosome 16.

Four gene loci; two each on chromosome 16. (Humans need four gene loci that code for the alpha hemoglobin chain in order to make their full component of normal hemoglobins. Two alpha chain gene loci are found on each chromosome 16. Beta globin gene (and other beta-like genes) are coded on chromosome 11.)

Which hemoglobin, when elevated, acts as a protection against sickling in patients with HbS? Hemoglobin E Hemoglobin C Hemoglobin F Hemoglobin D

Hemoglobin F (Increased levels of HbF interfere with the polymerization of HbS, therefore inhibiting sickling of red blood cells and increasing red blood cell survival time. HbE, HbC, and HbD all participate in the polymerization process with HbS.)

Which of the following bone marrow processing procedures is best suited for a patient who had a dry tap? Direct differential smear Touch preparations Concentrate (buffy coat) smears Crush smear

Touch preparations (When a patient has a dry tap, the physician was unable to collect a bone marrow aspirate. Therefore, the only remaining specimen is a bone marrow biopsy. Touch preparations, also known as imprints, are made by touching the biopsy against the slide. Direct differential smears, concentrate (buffy coat) smears, and crush smears are all performed on bone marrow aspirates.)

The following polypeptide chains are found in normal adult hemoglobin A: Alpha and gamma Alpha and delta Beta and delta Alpha and beta

Alpha and beta (A normal hemoglobin molecule is a tetramer made up of two alpha and two beta chains. A fetal hemoglobin molecule is a tetramer made up of two alpha and two gamma chains. Hemoglobin A2 is a tetramer made up of two alpha and two delta chains. Beta and delta globin genes reside in close proximity on the same arm of chromosome 11. The two do not assort together. However, 2 delta and two alpha globin chains form HbA2. Only a limited amount of delta chain is synthesized, limiting the amount of HbA2. In a normal adult, HbA2 accounts for about 2.5% of total adult hemoglobin.)

During phagocytosis by a neutrophil, the granules which fuse with the phagosome (phagocytic vacuole) can contain all of the following EXCEPT: Lysozyme Myeloperoxidase Lactoferrin Lactase

Lactase (Neutrophils are phagocytes, which means they ingest harmful microorganisms or other foreign particles that enter the body. When these foreign bodies are engulfed, granules containing digestive enzymes and cytotoxic proteins are released into the phagocytic vacuole, and the foreign body is destroyed. However, lactase is not one of the enzymes in a neutrophil and is not considered antibacterial. The primary or azurophilic granules can contain lysozyme, an antibacterial substance. The primary granules can also contain myeloperoxidase, which participates in the oxygen-dependent killing of bacteria. Lactoferrin contained in secondary or specific granules has antibacterial functions as well.)

Pluripotential stem cells are capable of producing which of the following? Only T-lymphocyte and B-lymphocyte subsets Erythropoietin, thrombopoietin, and leukopoietin Lymphoid and myeloid stem cells Daughter cells from only a single cell line

Lymphoid and myeloid stem cells (Pluripotential stem cells have the potential to self-renew, proliferate, and are ultimately capable of differentiating into all cell lines, including: erythrocytic, myeloid, lymphoid, and megakaryocytic cell lines.)

The MOST accurate observation about osmotic pressure is that it is: Proportional to concentration of solute particles Equal to number of solvent molecules times a factor Measurable by how much it raises the freezing point of water Directly proportional to the inverse log of solvent molecules

Proportional to concentration of solute particles (The osmotic pressure does not depend on the solute type or its molecular size but only on its molar concentration, the concentration of solute particles. There is no factor involved nor inverse log involved in the osmotic pressure in relation to the solvent molecules in the sample. Osmolality is measurable by how much it depresses the freezing point of samples.)

Aspirin ingestion prevents the synthesis of this signaling molecule in the platelet? Thromboxane A2 Calcium Collagen ADP

Thromboxane A2 (Thromboxane A2 is required to stimulate the activation of new platelets and aids in platelet aggregation. Aspirin ingestion inhibits the COX-1 enzyme that prevents the arachidonic pathway from synthesizing thromboxane A2. Aspirin has no effect on the synthesis of calcium. Aspirin has no effect on the synthesis of collagen. Aspirin has no effect on the synthesis of ADP.)

Note the view of a peripheral blood smear in the photograph. Pictured are scattered acanthocytes, echinocytes, target cells, spherocytes, schistocytes and a Howell-Jolly Body. The condition in which each of these atypical RBC's may be found in the same patient's peripheral blood smear is: Hemolytic anemia Postsplenectomy syndrome Disseminated intravascular coagulation Thalassemia minor

Postsplenectomy syndrome (The scattered atypical RBCs seen in the photograph may be produced in small numbers in normal people; however, the spleen is efficient in removing these from the circulation so that they are not found in a peripheral blood smear of a disease-free, untreated patient. However, following splenectomy, scattered acanthocytes, echinocytes, target cells, spherocytes, schistocytes, and Howell-Jolly bodies remain in the circulation. In hemolytic anemia, the significant morphological finding is microspherocytes. In disseminated intravascular coagulation (DIC), the significant morphological findings are schistocytes. In thalassemia minor, the significant morphological findings are target cells.)

In an adult, hematopoiesis occurs in which of the following listed sites? Liver Spleen Pancreas Proximal ends of long bones

Proximal ends of long bones (In an adult, hematopoiesis occurs in the marrow of the vertebrae, skull, and proximal ends of long bones, as well as in the bone marrow of the ribs and pelvis in adults. The liver and spleen are sites of hematopoiesis in the fetus, while the pancreas is not involved in the hematopoiesis.)

Which of the following statements are true for the hematopoietic cords? Hematopoietic cells develop at random locations in the marrow cells Reticular cells (adventitial cells) provide support for developing hematopoietic cells within the hematopoietic cords Lymphocytes are not seen in normal marrow Fat cells content of bone marrow decrease with aging

Reticular cells (adventitial cells) provide support for developing (Bone marrow is made up of hematopoietic cells, adipose tissue, osteoblasts and osteoclasts, and stroma. Hematopoietic cell colonies are organized in hematopoietic cords. After maturation in the hematopoietic cords, the hematopoietic cells pass through the walls of the sinuses, specialized vascular spaces, and end up in the circulating blood. Reticular cells (adventitial cells) provide structural support for the endothelial cells that line the venous sinus and the developing blood cells within the hematopoietic cord. The cytoplasm of the reticular cells is capable of extending itself in fiber-like strands deep into the hematopoietic cords. These strands provide a meshwork for the blood cells. Other types of cells which furnish support in the cord include macrophages and fat cells. Within the hematopoietic cords each cell line has a specific location for development. Like any other blood cell lineage, lymphocytes also arise from pluripotential hematopoietic stem cell found in the bone marrow. Fat cell content increases with age, and the average adult has about 50% fat cells (adipose cells) that make up the volume of their bone marrow.)

An assessment of the myeloid to erythroid (M:E) ratio is part of every bone marrow evaluation. Which of the following does not apply to the M:E ratio? -The erythroid total used in calculating the M:E ratio is the sum of all the nucleated red cell precursors. -The myeloid total used in calculating the M:E ratio is the sum of all non-RBC cell types found in the marrow. -White blood cells used in the myeloid tally/total used to calculate the M:E ratio include neutrophil precursors as well as eosinophil precursors and basophil precursors. -The M:E should always be interpreted in context with the overall bone marrow cellularity.

-The myeloid total used in calculating the M:E ratio is the sum of all non-RBC cell types found in the marrow. (The M:E ratio is calculated from the total granulocyte precursors and the total erythroid precursors. It does not include non-myeloid nucleated cells such as lymphocytes, monocytes etc. It should always be interpreted in context with the overall bone marrow cellularity. Although laboratories may have slightly different reference ranges, the typical reference range for the M:E ratio is 2:1 - 4:1.)

What is the normal ratio of erythroid to myeloid cells found in the normal bone marrow? The correct answer is highlighted below 1:1 - 2:1 1:5 1:3 1:10

1:3 (The normal myeloid to erythroid ratio is 1.5:1 to 3:1. The question asked: erythroid to myeloid, therefore, the only valid alternate is 1:3, the third answer choice. The first answer choice is incorrect. In normal bone marrow, myeloid lineage outnumbers erythroid lineage. The second and fourth answer choices are also incorrect. The reference range for M : E ratio is 1.5 : 1 to 3: 1. If segmented neutrophils are included, the M : E reference range is 2:1 to 4:1. i.e, E:M = 1:2 to 1:4.)

Which of the following represents the percent population of T-helper cells in this sample data? absolute lymphocyte count= 2.4 x 109/L %CD3 = 60 %CD4 = 40 %CD8 = 20 - 20% - 40% - 60% - 80%

40% (T-helper cells are CD4 positive. The flow results reflected 40% CD4. CD3 is a pan T cell marker (and should reflect CD4 plus CD8). CD8 is the cytotoxic/suppressor T cell marker.)

What is the normal cellularity of an iliac crest bone marrow biopsy in a 50-year-old male: The correct answer is highlighted below 20% 35% 50% 65%

50% (A general estimate of the expected normal cellularity range in an adult can be determined by first subtracting the age of the patient from 100%. The range is then +/- 10 of that number. Therefore, a normal, healthy 50-year-old should have an overall cellularity between 40% and 60%. Note that the iliac crest is the preferred site for bone marrow collection in adult.)

What is the cause of iron overload in hereditary hemochromatosis? -Absorption of excessive amounts of iron in the small intestine -Ingestion of excessive amounts of iron from diet or supplements -Inability of the body to excrete normal amounts of dietary iron -Failure of developing red blood cells to incorporate iron into protoporphyrin IX

Absorption of excessive amounts of iron in the small intestine (Hereditary hemochromatosis is a genetic disorder typically involving a deficiency of hepcidin due to a mutation in the hepcidin gene or genes whose products regulate the expression of hepcidin. These mutations cause increased iron absorption in the small intestine, leading to iron overload. Ingestion of excessive amounts of dietary iron results in secondary hemochromatosis. Iron is recycled when cells die; the body does not have a mechanism for iron excretion. Failure of developing red blood cells to incorporate iron into protoporphyrin IX results in sideroblastic anemia.)

Which of the following is a mechanism known to cause platelet satellitosis (satellitism)? An antibody directed against factor VIII An antibody directed against von Willebrand factor (vWF) An antibody directed against the platelet membrane An antibody directed against fibrinogen

An antibody directed against the platelet membrane (Platelet satellitosis is an in vitro phenomenon where platelets adhere to or surround neutrophils in specimens anticoagulated with EDTA. This is due to a platelet-specific autoantibody. Platelet satellitosis may cause pseudothrombocytopenia when using automated methods for the platelet count. Specimens can be recollected in sodium citrate and reanalyzed. The platelet count from the analyzer must now be multiplied by 1.1 to account for the dilution of blood with the anticoagulant. Platelet satellitosis does not result from antibodies directed against factor VIII, vWF, or fibrinogen.)

Which of the following is responsible for the humoral immune response: Neutrophils Basophils B lymphocytes Monocytes

B lymphocytes (Humoral immunity involves antibody production. Most B lymphocytes participate in the humoral response through their transformation into plasma cells and secretion of antibodies. Other B cells become long-lived memory cells. Neutrophils are part of cellular immunity. Their major function is phagocytosis and destruction of foreign material and microorganisms. Basophil granules contain histamine, and they play a vital role in allergic reactions and the inflammatory response. Monocytes are phagocytic cells and recognize bacterial pathogens. While monocytes do present antigens to B-lymphocytes to initiate the adaptive immune response, it is the B lymphocyte that is responsible for the antibody production of the humoral immune response.)

Which of the following hemoglobins is replaced by hemoglobin H (HbH) after birth in individuals with HbH disease? Constant Spring A2 Lepore Bart's

Bart's (HbH disease is a symptomatic but nonfatal form of alpha thalassemia. There is a dramatic reduction (25-30%) in alpha-chain synthesis, resulting in decreased levels of HbA, HbA2, and HbF. Excess beta- and gamma-chains accumulate because of the decreased alpha-chain synthesis. Before birth, excess gamma-chains form tetramers, or Hb Bart's. After birth, beta-chain synthesis increases, leading to beta-chain tetramers, or HbH. HbH eventually replaces Hb Bart's as gamma-chain synthesis decreases around birth. Hb Constant Spring (HbCS) is a tetramer of two structurally abnormal alpha-chains and two normal beta-chains. Clinical findings in HbCS homozygotes are like those of a mild form of HbH disease. HbA2 is decreased in HbH disease due to decreased production of alpha-chains. It is characteristically increased, however, in beta thalassemia. Hb Lepore consists of two normal alpha-chains and two delta/beta-globin hybrid chains. Hb Lepore has similar pathophysiology to that of beta thalassemia.)

Where is the main site of action for monocytes after diapedesis? Peripheral blood Body tissues Bone marrow Digestive tract

Body tissues (Diapedesis is the process in which blood cells pass through capillary walls. Monocytes function in the immune system by responding to inflammation signals and moving to sites of infection in the tissues. There, monocytes divide and differentiate into macrophages and dendritic cells to elicit an immune response.)

Which of the following phenotypes is most indicative of a natural killer (NK) cell? The correct answer is highlighted below CD2+ CD3+ CD5+ CD7+ CD2+ CD3- CD11b+ CD16+ CD11b+ CD16+ CD33+ CD56- CD19+ CD20+ CD22+ CD57-

CD2+ CD3- CD11b+ CD16+ (NK cells express CD2, CD11b, and CD16; NK cells do not express CD3, a T cell marker. Other NK cell markers include CD7, CD56, and CD57. CD2, CD3, CD5, and CD7 are all mature T cell markers. CD2 and CD7 are also NK cell markers; however, NK cells are CD3- and CD5-. Although NK cells express CD11b and CD16, CD33 is expressed by monocytes and other myeloid cells. NK cells are CD56+. CD19, CD20, and CD22 are all B cell markers. NK cells are CD57+.)

All helper cells are T cells. Consequently, in a normal lymphocyte population, it is reasonable to expect all CD4-positive cells to also be positive for which of the following CD markers? a. CD3 b. CD20 c. CD33 d. CD41 and CD42

CD3 (CD4 positive cells are helper T cells. All T lymphocytes are positive for the CD3 marker. CD20 is a B cell marker. CD33 is a granulocytic/monocytic cell marker. CD41 and 42 are megakaryocytic cell markers.)

Which of the following is the proper designation for the pluripotential stem cell that is a precursor for both myeloid and lymphoid cell lines? CFU-S CFU-GEMM G-CSF CFU-GM

CFU-S (CFU-S stands for colony-forming unit spleen - it is the pluripotential stem cell that gives rise to all cell lines. CFU-GEMM is a multilineage precursor for granulocyte, erythrocyte, macrophage, and megakaryocyte. G-CSF is the precursor committed to granulocyte cell lines. CFU- GM is the precursor for granulocyte and monocyte cell lines.)

Which of the following is a hormone produced in the kidney that is responsible for triggering the production of red blood cells? Thrombopoietin Erythropoietin Thyroxine Estrogen

Erythropoietin (Erythropoietin is correct. It is a hormone primarily produced by the kidney that can trigger erythropoiesis, the formation and development of red blood cells. Thrombopoietin is a hormone produced by the liver and the kidney that promotes the production of platelets. Thyroxine is a thyroid hormone. It is commonly measured in the chemistry department of the clinical laboratory. Estrogen is a female reproductive hormone.)

Which hormone is produced by the kidney and influences erythrocyte production? Growth hormone Erythropoietin Interleukin 3 ALA synthetase

Erythropoietin (Erythropoietin, or EPO, is created in the kidney and signals the bone marrow to produce more red blood cell precursors. EPO is simulated during anemia and conditions that lead to low blood oxygen levels. Growth hormone (GH) is produced by the anterior pituitary. GH promotes hepatic gluconeogenesis (noncarbohydrate glucose pathway), stimulates lipolysis (breakdown of lipids and fats), and enhances protein synthesis in skeletal muscles and other tissues. Interleukin 3 (IL-3) is a hematopoietic growth factor produced by activated T lymphocytes and mast cells. The mature cell targets are eosinophils and monocytes. ALA (aminolevulinic acid) synthetase is the first enzyme in heme biosynthesis. This enzyme facilitates the formation of 5-aminolevulinic acid from glycine and succinyl coenzyme A.)

The percentage of red blood cells in whole blood is called: Hemoglobin Hematocrit Hemostasis Hemopoiesis

Hematocrit (Hematocrit is the percentage of red blood cells in whole blood. Hemoglobin is the iron containing pigment found in red blood cells whose function is to bind oxygen and carbon dioxide and help their transport through the circulatory system. Hemostasis is the process by which the body stops the bleeding after an injury, it is also known as the coagulation process. Hemopoiesis is the production of and development of blood cells. Hemopoiesis usually takes place in the bone marrow.)

The abnormalities that are seen on this slide are probably associated with which of the following conditions? (Fine BASOPHILIC STIPPLING) Lead poisoning Increased red cell production There are no abnormalities on this slide Decreased red blood cell production A red blood cell with fine basophilic stippling and a polychromatophilic cell are present on this slide. Both of these are associated with increased production of red cells. Lead poisoning would be consistent with coarse basophilic stippling with the red blood cells in many of the cells. In this clinical picture, there is a polychromatic cell indicating that a condition exists where there is an increase in new, slightly immature cells are being released into the peripheral circulation.

Increased red cell production (A red blood cell with fine basophilic stippling and a polychromatophilic cell are present on this slide. Both of these are associated with increased production of red cells. Lead poisoning would be consistent with coarse basophilic stippling with the red blood cells in many of the cells. In this clinical picture, there is a polychromatic cell indicating that a condition exists where there is an increase in new, slightly immature cells are being released into the peripheral circulation.)

The granules of Basophil contain which of the following? Antihistamine IgE The contents of helminth digestion Initiators of allergic inflammation

Initiators of allergic inflammation (Basophils are the initiators of allergic inflammation through the release of preformed cytokines. Basophil granules do contain histamine, and antihistamine is commonly prescribed to counteract this in the inflammatory response. Although basophils are contributors to the response against helminths and other parasites, the destruction of these parasites is carried out by the eosinophils through the secretion of major basic protein and eosinophil cationic protein. Basophils have IgE receptors on their surface membranes. The plasma cell is the only producer of immunoglobulins such as IgE.)

Which of the following statements is true regarding macrophages (histiocytes)? -It is a form of lymphocyte that is capable of cell lysis. -It is a type of monocyte that has entered the tissues via diapedesis. -It is a cell found in tissues with numerous basophilic granules in the cytoplasm. -It is a type of eosinophil that has immunoglobulins on the surface to recognize invading parasites.

It is a type of monocyte that has entered the tissues via diapedesis. (Essentially, macrophages are older monocytes that have migrated out of the peripheral blood. Monocytes circulate through the peripheral blood and eventually enter the tissues and body fluids via diapedesis and mature into macrophages. Lymphocytes, basophil (mast cell in tissues), and eosinophil are not related to macrophages.)

Which of the following cells is the most common nucleated cell in normal adult bone marrow? Myeloblast Promyelocyte Myelocyte Metamyelocyte

Metamyelocyte (Of the given choices, metamyelocytes are the most abundant form seen in a normal bone marrow. Reference interval is 3-20% Myeloblast reference interval is 0-3%. Promyelocyte reference interval is 1-5%. Myelocyte reference interval is 6-17%.)

What is another name used to designate a fully committed B-lymphocyte: T-lymphocyte Reactive lymphocyte Large lymphocyte Plasma cell

Plasma cell Plasma cell is the correct answer here. Plasma cells are the end stage of B lymphocyte maturation; they are not normally seen in peripheral blood. T-lymphocytes are one of the lymphocyte populations, the other one being the B-lymphocytes. Reactive lymphocytes are variant lymphocytes or atypical lymphocytes. An atypical lymphocyte is often irregular in shape and may have a round, ovoid or indented nucleus. Reactive lymphocytes may be large and exhibit deep blue to pale gray cytoplasm.

In which developmental stage do red blood cells begin forming hemoglobin in amounts large enough to be visualized on a Wright-stained bone marrow aspirate smear? Reticulocyte Pronormoblast Basophilic normoblast Polychromatic normoblast

Polychromatic normoblast (Hemoglobin synthesis is detectable in the basophilic normoblast, but the formation of large amounts of hemoglobin begins in the polychromatic (polychromatophilic) normoblast. On a Wright-stained bone marrow aspirate smear, the cytoplasm of the polychromatic normoblast is murky gray-blue, which is due to a mixture of pink (from hemoglobin) and blue (from RNA). The cytoplasm of the basophilic normoblast is a deep, rich blue; any amount of hemoglobin produced during this stage is masked by the presence of large amounts of ribosomes and RNA.)

The radioactive method used to measure red cell survival uses which of the following isotopes? I125 51Cr P31 14C

51Cr (In normal individuals, the erythrocyte survival half-time, as measured by the chromium 51 labeling technique, generally ranges between 25 and 35 days. This apparent short survival time, when compared to the 120-day life span of the red blood cells, is due to the elution of chromium from the cells and to cell damage that probably occurs during the process of withdrawing them from the body and labeling. Subnormal survival times may be indicative of blood loss, sequestration of red blood cells by the spleen, or shortened cell viability.)

Which morphologic term describes this slide? Alder-Reilly neutrophils Auer rods Döhle bodies, bacteria, toxic granulation Pelgeroid neutrophils

Alder-Reilly neutrophils (Alder-Reilly anomaly is inherited through an autosomal recessive mechanism. With this condition, white blood cells are characterized by the accumulation of cytoplasmic granules containing mucopolysaccharides. When the slide is stained with a Wright stain, these granules often appear dark purple/blue. In contrast, on this stain the granules appear red. Patients with Alder-Reilly anomaly have neutrophils with qualitative changes that resemble toxic granulation. One way to differentiate between toxic granulation and Alder-Reilly anomaly is that the bountiful granulation is seen in a higher percentage of neutrophils in patients with Alder-Reilly versus patients with toxic granulation. Additionally, in Alder-Reilly anomaly the prominent granulation can be found in all varieties of leukocytes. Auer rods are only seen in malignant myeloblasts and promyelocytes. They present as variably sized pink rods in the cytoplasm. Döhle bodies, toxic granulation, and bacteria are often seen in sepsis. Döhle bodies present as small blue-gray cytoplasmic inclusions. Bacteria are typically dark staining but are larger than cytplasmic granules. Pelgeroid cells are hyposegmented mature neutrophils. Pelgeroid cells may have one or two lobes.)

Which of the following is NOT required for a diagnosis of hereditary hemochromatosis (HH)? >50% transferrin saturation in females or >60% saturation in males Presence of HFE mutations or other genetic mutations associated with iron metabolism Increased ferritin Biopsy of liver and/or bone marrow

Biopsy of liver and/or bone marrow (For hereditary hemochromatosis (HH), a biopsy of the liver and/or bone marrow are not typically needed as iron chemistries and/or genetic testing are efficient at properly identifying this disease. Patients with HH will have elevated transferrin saturation, often possess a genetic mutation affecting iron metabolism, and an increased serum ferritin.)

A normal hemoglobin molecule is comprised of the following: Ferrous iron and four globin chains Four heme and four globin chains Four heme and one globin chain One heme and four globin chains

Four heme and four globin chains (A normal hemoglobin molecule consists of a tetramer, of four heme and four globin chains, with a molecular weight of 64,500 daltons. Each of the four units can bind a molecule of oxygen for transport to the body's tissues. In the image shown below, there are four monomers (2 red globin chains and 2 blue globin chains) which form the entire hemoglobin tetramer structure. The green portions represent the 4 heme groups.)

The mediator cell type that binds to IgE antibodies is the: Basophil Eosinophil Polymorphonuclear neutrophil (PMN) Macrophage

Basophil (Basophils have high concentrations of heparin and histamine in their granules, which play an important role in the acute system, hypersensitivity reactions. Degranulation occurs when an antigen such as pollen binds to two adjacent immunoglobulin E (IgE) antibody molecules located on the surface of mast cells. The events resulting from the release of the contents of these basophilic granules include increased vascular permeability, smooth muscle spasms, and vasodilation. If severe, this reaction can result in anaphylactic shock. Eosinophils are considered homeostatic regulators of inflammation. Functionally, this means that the eosinophil attempts to suppress an inflammatory reaction to prevent the excessive spread of the inflammation. Polymorphonuclear neutrophils (PMNs) are the principal leukocyte associated with phagocytosis and a localized inflammatory response. PMNs can prolong inflammation by the release of soluble substances, such as cytokines and chemokines. Macrophages and monocytes are phagocytic cells. Macrophages can be activated during infection by the release of macrophage-activating cytokines, e.g., interferon-gamma and granulocyte colony-stimulating factor from T lymphocytes. Macrophages exposed to an endotoxin release a hormone, tumor necrosis factor.)

What is the approximate percentage of individuals in the US who are heterozygous for HFE mutations for hereditary hemochromatosis? 0.05% to 0.10% 1% to 2% 10% to 12% 20% to 25%

10% to 12% (Hemochromatosis is a form of iron overload, or accumulation of excess iron. The condition affects the skin, liver, pancreas (traditionally called "bronzed diabetes"), and the heart. Hemochromatosis may be an acquired condition or inherited. In hereditary form of hemochromatosis, a mutation in the HFE gene is the most common cause. Early diagnosis and treatment can prevent these secondary effects of iron overload. Approximately 10% to 12% of individuals in the US are heterozygous for HFE mutations. The most common causative HFE mutation is the homozygous Cys282Tyr (C282Y) mutation. Prevalence is high in white population (homozygote 3-5%) but almost absent in non-white population. In northern Europeans, heterozygosity approaches 13%.)

What is the expected life span of a normal red blood cell? 3-4 months 1-2 months 3-6 weeks 1-3 weeks

3-4 months (The life span of normal red blood cells in the circulation is approximately 120 days (about four months). Aging red blood cells are removed primarily via extravascular catabolism. Conditions that cause the destruction of red blood cells decrease the normal life span. Additional information: The mean average life span of an RBC in premature infants is 35 to 50 days. The life span of RBCs in fetuses is between 60 and 70 days.)

B lymphocytes and T lymphocytes are derived from: Hematopoietic stem cells Macrophages or monocytes Mucosa-associated lymphoid tissue (MALT) Granulocytes

Hematopoietic stem cells (All lymphocytes originate and are therefore derived from, hematopoietic stem cells via hematopoiesis. The stem cells eventually mature into common lymphoid progenitor cells. The progenitor cells then differentiate into their distinct lymphocyte types. B cells mature into B lymphocytes in the bone marrow, while T cells migrate to and mature in the thymus.)

When red blood cells hemolyze, what is the molecule released that will give the plasma its reddish appearance? Sodium Potassium Hemoglobin Glucose

Hemoglobin (Hemoglobin is the oxygen-carrying molecule normally present within red cells that gives the red appearance to hemolyzed plasma. Although hemolysis can have many causes, proper specimen handling, including correct centrifugation procedure, will reduce the risk of damage to red blood cells and the introduction of hemoglobin into plasma or serum. Glucose, potassium, and sodium are colorless.)

A 3-year-old girl was brought to a physician's office because of fever and bacterial-type illness symptoms. Her blood pressure was elevated. Gram stain of peripheral blood shows Gram-negative rods. Hemogram: hemoglobin 9.1g/dL (normal 12.0 - 16.0 g/dL), hematocrit 28% (normal 37 - 48%), MCV 80 fl (normal 86 - 98 fl), RDW 13.1% (normal 11 - 15%), platelets 85.1 X 109/L (normal 150 - 450 X 109/L) WBC 9.9x109/L (normal 4.3 - 10.8 x 109/L). The peripheral blood smear is represented in the photograph(spherocytes, schistocytes, and helmet cells). Which of the following is the most likely associated condition? Hereditary spherocytosis Thrombotic thrombocytopenic purpura (TTP) Hemolytic uremic syndrome (HUS) Hereditary pyropoikilocytosis (HPP)

Hemolytic uremic syndrome (HUS) (The presence of polychromatic erythrocytes (blue arrow in the upper photograph) and scattered spherocytes support a hemolytic process. Scattered schistocytes and helmet cells are present in HUS. A platelet count of 85,000/uL (normal range 150,000-450,000/uL) is compatible with thrombotic thrombocytopenic purpura (TTP). Spherocytes would appear as the predominant erythrocytes in a case of hereditary spherocytosis. Hemoglobin is often normal, but infection, fever, and stress can cause the spleen to destroy more red blood cells. If this had occurred, the hemoglobin would be low, but the patient would also appear jaundiced due to an increase in bilirubin. Unlike TTP, HUS is characterized by association with an E.coli O157:H7 infection in roughly 80% of cases. This can lead to renal failure due to the destruction of red blood cells. Though there are cell fragments/poikilocytosis in hereditary pyropoikilocytosis. This autosomal recessive trait is usually seen in infancy with an MCV that is most likely to be much lower than 50 (range of 25-55 fL). The fragmentation is due to heat for these patients, not from a bacterial infection.)

Whole blood if composed of approximately: 75% formed elements and 25% plasma 60% formed elements and 40% plasma 45% formed elements and 55% plasma 30% formed elements and 70% plasma

45% formed elements and 55% plasma (Whole blood is composed of 45% formed elements and 55% plasma. This is helpful information, especially when blood is collected, as about half of the volume of blood drawn will be serum or plasma.)

Which type of granulocyte has water soluble granules which may fade during the rinsing phase of the staining process using the Wright's stain? Neutrophilic segs Eosinophils Basophils Neutrophilic bands Feedback Basophils contain substances such as histamine and heparin which are important in inflammatory and allergic responses. Many of the basophil's granules are water-soluble, and thus could wash out or get lighter if the rinsing step during the staining process is prolonged. Segmented neutrophils, eosinophils, and banded neutrophils all contain cytoplasmic granules, but they are not as susceptible to fading during the rinsing step of the Wright's stain procedure.

Basophils (Basophils contain substances such as histamine and heparin which are important in inflammatory and allergic responses. Many of the basophil's granules are water-soluble, and thus could wash out or get lighter if the rinsing step during the staining process is prolonged. Segmented neutrophils, eosinophils, and banded neutrophils all contain cytoplasmic granules, but they are not as susceptible to fading during the rinsing step of the Wright's stain procedure.)