B4M1 24-25 Flashcards
Which organ becomes the main site for red blood cell production during the middle trimester of gestation?
A. Yolk sac
B. Spleen
C. Liver
D. Bone marrow
D. Bone marrow
If a patient is exposed to low oxygen levels, what changes would you expect in the production of erythrocytes?
A. Decreased production of erythrocytes
B. No effect on erythrocyte production
C. Increased production of erythrocytes due to growth inducers
D. Immediate differentiation of erythrocytes into white blood cells
C. Increased production of erythrocytes due to growth inducers
In the erythroid lineage, what is the latest cell capable of mitosis?
A. Polychromatic normoblast
B. Basophilic normoblast
C. Orthochromatic normoblast
D. Metachromatic normoblast
A. Polychromatic normoblast
What is the function of erythropoietin (EPO) in hematopoiesis?
A. Stimulates lymphocyte production
B. Regulates platelet aggregation
C. Promotes red blood cell production
D. Enhances neutrophil migration
C. Promotes red blood cell production
A 28-year-old female presents with fainting, low-grade fever, and gingival bleeding for 3 days. CBC reveals pancytopenia, a peripheral blood smear shows large cells with prominent nucleoli, abundant deep blue granules, and Auer rods in the cytoplasm. What cells are identified in the patient’s smear?
A. Metamyelocyte
B. Myelocyte
C. Myeloblast
D. Promyelocyte
D. Promyelocyte
Which of the following generally describes the maturation process of the erythroid series?
A. N:C ratio increases, with production of primary and secondary granules
B. N:C ratio decreases while chromatin density increases, mitochondria and organelles gradually disappear
C. Enlarging nucleus with several small nucleoli; cytoplasm extends branching processes eventually forming a teardrop-shaped enlargement
D. Increasing nuclear size with formation of bluish to purplish stipplings
B. N:C ratio decreases while chromatin density increases, mitochondria and organelles gradually disappear
In a normal adult hemoglobin (HbA), the four polypeptide chains are compoed of:
A. Two alpha-chains and two beta-chains
B. Two alpha-chains and two delta-chains
C. Two alpha-chains and gamma-chains
D. One alpha-chain and three beta-chains
A. Two alpha-chains and two beta-chains
What is the earliest recognizable erythroid precursor and is also the largest of the erythroid precursors?
A. Polychromatophilic normoblast
B. Orthochromatic normoblast
C. Basophilic normoblast
D. Pronormoblast
D. Pronormoblast
Which of the following is the correct sequence of erythrocyte development?
A. Rubriblast > Rubricyte > Prorubricyte > Metarubricyte > Reticulocyte > Mature erythrocyte
B. Rubiblast > Metarubricyte > Prorubricyte > Rubricyte > Reticulocyte > Mature erythrocyte
C. Rubriblast > Prorubricyte > Rubricyte > Metarubricyte > Reticulocyte > Mature erythrocyte
D. Rubriblast > Rubricyte > Metarubricyte > Prorubricyte > Reticulocyte > Mature erythrocyte
C. Rubriblast > Prorubricyte > Rubricyte > Metarubricyte > Reticulocyte > Mature erythrocyte
What key characteristic distinguishes a metamyelocyte from a myelocyte?
A. Appearance of specific granules
B. Development of threadlike filaments within nucleus
C. Indentation of nucleus
D. Nucleus flattened to one side forming a characteristic D shape
C. Indentation of nucleus
What causes the characteristic pus formation at the site of infection?
A. Accumulation of dead neutrophils and bacteria
B. Granuloma formation by macrophages and CD cells
C. Collection of hyaluronic acid, anaphylatoxins, and plasma proteins
D. Aggregates of oxidized red blood cells and immunoglobulins
A. Accumulation of dead neutrophils and bacteria
Eosinophil-specific granules contain ______, which is a substance that is toxic to parasites and host cells, neutralizes heparin, and stimulates histamine release from basophils.
A. Arylsulfatase
B. Alkaline phosphatase
C. Eosinophil-derived neurotoxin
D. Major basic protein
D. Major basic protein
Histamine, heparin, and PAF, are mediators of immediate hypersensitivity which are released upon degranulation of which leukocyte?
A. Basophil
B. Eosinophil
C. Lymphocyte
D. Neutrophil
A. Basophil
What is a distinctive feature of the macrophage nucleus?
A. Multi-lobed
B. Bi-lobed
C. Large and oval or kidney-shaped
D. Absent
C. Large and oval or kidney-shaped
Which type of cells do monocytes differentiate into upon entering tissues?
A. Neutrophils
B. Lymphocytes
C. Erythrocytes
D. Macrophages
D. Macrophages
What cells will develop antigen receptors when they mature?
A. Lymphocytes
B. Erythrocytes
C. Monocytes
D. Eosinophils
A. Lymphocytes
Which cells are responsible for producing immunity against a disease after the first exposure of the same disease?
A. T cells
B. Macrophage
C. Memory B cells
D. Cytotoxic T cells
C. Memory B cells
What is the primary function of plasma cells?
A. The production of hormones
B. The generation of red blood cells
C. The production of antibodies
D. The storage of fat
C. The production of antibodies
Which morphological features help in identifying a plasma cell?
A. A clear zone adjacent to the nucleus with clumped chromatin in a wheel-like pattern
B. A central nucleus with uniform chromatin distribution
C. Lack of cytoplasm and clear nuclear boundaries
D. Multi-lobed nucleus with abundant red cytoplasm
A. A clear zone adjacent to the nucleus with clumped chromatin in a wheel-like pattern
Growth factors are required to stimulate the production of blood cells. Which growth factor is required for the production of megakarytocytes?
A. EPO
B.IL-5
C. IL-1
D. TPO
D. TPO
What is the correct sequence of cells in megakarytopoiesis?
A. Promegakaryocyte, Megakaryocyte, Megakaryoblast, Platelets
B. Megakaryocyte, Megakaryoblast, Promegakaryocyte, Platelets
C. Megakaryoblast, Promegakaryocyte, Megakaryocyte, Platelets
D. Platelets, Megakaryocyte, Promegakaryocyte, Megakaryoblast
C. Megakaryoblast, Promegakaryocyte, Megakaryocyte, Platelets
Which of the following statements accurately describs platelets?
A. Platelets are biconcave disc-shaped with an area of central pallor
B. The average lifespan of platelets in the circulation is 10 days
C. Metamyelocytes differentiate into mature platelets
D. Circulating platelets make up one-third of the platelets released from the bone marrow
B. The average lifespan of platelets in the circulation is 10 days
A CBC report shows a high Red Cell Distribution Width (RDW) value. What could this indicate about the patient’s red blood cells?
A. The red blood cells have uniform size and shape
B. There is a greater variation in the size of red blood cells
C. The hemoglobin concentration is abnormally low
D. The platelet count is higher than normal.
B. There is a greater variation in the size of red blood cells
What does hematocrit (Hct) represent in a CBC test?
A. The amount of hemoglobin in a volume of blood
B. The ratio of volume of red cells to the volume of whole blood
C. The number of platelets in the blood
D. The concentration of white blood cells
B. The ratio of volume of red cells to the volume of whole blood
What chronic infection can cause monocytosis?
A. Hepatitis
B. Pertussis
C. Tuberculosis
D. Cytomegalovirus infection
C. Tuberculosis
What is expected of patients with parasitic infection?
A. Monocytosis
B. Eosinophilia
C. Basophilia
D. Lymphocytosis
C. Basophilia
Which component of hemoglobin directly binds to oxygen molecules?
A. Alpha chains
B. Beta chains
C. Heme group
D. Globular protein
C. Heme group
In which cellular compartment does the insertion of iron into protoporphyrin IX to form heme occur?
A. Cytoplasm
B. Nucleus
C. Mitochondria
D. Endoplasmic Reticulum
C. Mitochondria
This factor is responsible for most of the vasoconstrictive action of the affected vessel when hemostatic mechanism commences?
A. Thromboxane A2 derived from platelets
B. Direct damage to vascular wall
C. Nervous reflexes initiated by pain nerve impulses
D. Local myogenic tissue hyperactivity
B. Direct damage to vascular wall
What is the expected life-span of thrombocytes within the systemic circulation?
A. 6-8 days
B. 8-12 days
C. 10-14 days
D. 12-20 days
B. 8-12 days
Which of the following is the first step in the formation of a blood clot?
A. Platelet plug formation
B. Vasoconstriction of the blood vessel
C. Conversion of fibrinogen to fibrin
D. Activation of the extrinsic pathway
B. Vasoconstriction of the blood vessel
What role do platelets play in blood clot formation?
A. They release the tissue factor to activate the coagulation cascade
B. They form a temporary plug by adhering to the damaged vessel wall and to each other
C. They convert fibrinogen to fibrin to stabilize the clot
D. They activate calcium ions to strengthen the clot
B. They form a temporary plug by adhering to the damaged vessel wall and to each other
Which of the following describes the action of thrombin on fibrinogen to form fibrin?
A. Thrombin converts fibrinogen into fibrin by cleaving fibrinopeptides
B. Thrombin converts fibrinogen into fibrin by activating plasminogen
C. Thrombin converts fibrinogen into fibrin by binding calcium ions
D. Thrombin converts fibrinogen into fibrin by breaking down the phospholipid membrane
A. Thrombin converts fibrinogen into fibrin by cleaving fibrinopeptides
Which of the following best describes the initial step in the intrinsic pathway of blood coagulation?
A. Activation of Factor VII by tissue factor at the site of injury
B. Activation of Factor XII by contact with negatively charged surfaces such as exposed collagen
C. Conversion of firinogen to fibrin by thrombin
D. Activation of Factor X by tissue factor-Factor VII complex
B. Activation of Factor XII by contact with negatively charged surfaces such as exposed collagen
Which test is primarily used to assess the intrinsic pathway of coagulation?
A. Clotting Time
B. Activated Partial Thromboplastin Time (APTT)
C. Bleeding Time
D. TOurniquet Test
B. Activated Partial Thromboplastin Time (APTT)
During a tourniquet test, if bleeding continues after the tourniquet is released, what does this suggest?
A. Normal hemostatic function
B. Possible vascular or platelet dysfunction
C. Increased clotting factor activity
D. Effective platelet aggregation
B. Possible vascular or platelet dysfunction
Stress can cause an increase in:
A. Neutrophils
B. Lymphocytes
C. Basophils
D. Monocytes
A. Neutrophils
B. Lymphocytes
What is the last step in the extrinsic pathway?
A. The splitting of prothrombin to thrombin
B. The release of tissue factor
C. The activation of Factor X
D. The activation of Factor XII
A. The splitting of prothrombin to thrombin
What is the rate limiting factor in causing blood coagulation?
A. Formation of prothrombin activator
B. Conversion of prothrombin to thrombin
C. Conversion of fibrinogen to fibrin
D. Activation of tissue factor
A. Formation of prothrombin activator
This is a regulatory molecule that causes negative feedback when heme is produced in optimum or excessive amounts, resulting in repression in the actual heme synthesis:
A. Heme
B. Succinyl CoA
C. Porphobilinogen
D. Porphyrin
A. Heme
The number of protein chains in each hemoglobin molecule is:
A. 1
B. 2
C. 3
D. 4
D. 4
Heme consists of:
A. Pyrrolidine rings
B. Pyramidine rings
C. Purine rings
D. Pteridine rings
A. Pyrrolidine rings
The amino acid that participates in the binding of oxygen in hemoglobin:
A. Glycine
B. Histidine
C. Lysine
D. Proline
B. Histidine
Porphyrin rings in hemoglobin molecules contain which atom in their centers?
A. Magnesium
B. Iron
C. Hydrogen
D. Zinc
B. Iron
The oxygen combines with hemoglobin in the blood to form:
A. Oxyhemoglobin
B. Deoxyhemoglobin
C. Hemoglobin
D. Carboxyhemoglobin
A. Oxyhemoglobin
In sickle cell anemia, the basis of the malfunction of the hemoglobin molecule is:
A. Incorrect secondary structure
B. Substitution of a single amino acid
C. Faulty binding of the heme groups
D. Reduced affinity for oxygen
B. Substitution of a single amino acid
In deoxy hemoglobin (Hb), the Fe (II) is 5-coordinated to:
A. Four nitrogens of heme and to the proximal His of Hb
B. Four nitrogens of heme and to a water molecule
C. Four nitrogens of Heme and to an O2 molecule
D. Two nitrogens of heme and to three His residues in Hb
A. Four nitrogens of heme and to the proximal His of Hb
Spontaneous oxidation of the heme-bound Fe (II) to Fe (III) is prevented in hemoglobin by:
A. The symmetry of its quaternary structue
B. The four heme-protein covalent bonds
C. a highly-ordered water molecule within the heme pocket
D. The surrounding protein structure in each subunit
D. The surrounding protein structure in each subunit
Heme is synthesized by the incorporation of ferrous ion (Fe++) into protoporphyrin III being catalyzed by the enzyme:
A. Ferroxidase
B. Ferroreductase
C. Ferrochelatase
D. Ferroamidase
C. Ferrochelatase
Carboxyhemoglobin is formed by:
A. CO
B. CO2
C. HCO3
D. HCN
A. CO
