CSS - PMS - CCE - PCS - General Science
Blood System
Platelet aggregation forms the:
A. Primary hemostatic plug
B. Bile pigment
C. Red marrow cavity
D. Antibody complex
Correct Answer: A
Activated platelets adhere to one another to form the primary platelet plug.
CSS - PMS - CCE - PCS - General Science
Blood System
Platelet adhesion at a damaged vessel wall is strongly supported by:
A. von Willebrand factor
B. Albumin only
C. Bilirubin
D. Erythropoietin
Correct Answer: A
von Willebrand factor helps platelets adhere to exposed subendothelial structures at sites of vascular injury.
CSS - PMS - CCE - PCS - General Science
Blood System
Immediately after small vessel injury, the first local response commonly includes:
A. Vasoconstriction
B. Hemolysis
C. Increased bile production
D. Bone formation
Correct Answer: A
Vascular spasm or vasoconstriction helps reduce blood loss immediately after injury.
CSS - PMS - CCE - PCS - General Science
Blood System
A low platelet count is termed:
A. Leukopenia
B. Thrombocytopenia
C. Polycythemia
D. Neutrophilia
Correct Answer: B
Thrombocytopenia is a decrease in circulating platelet count.
CSS - PMS - CCE - PCS - General Science
Blood System
Platelets are fragments derived from large bone marrow cells called:
A. Megakaryocytes
B. Monocytes
C. Reticulocytes
D. Myeloblasts only
Correct Answer: A
Platelets are cytoplasmic fragments shed from megakaryocytes in bone marrow.
CSS - PMS - CCE - PCS - General Science
Blood System
A decrease in total white blood cell count is called:
A. Leukocytosis
B. Leukopenia
C. Erythrocytosis
D. Hemoconcentration
Correct Answer: B
Leukopenia means a reduced circulating white blood cell count.
CSS - PMS - CCE - PCS - General Science
Blood System
A rise in total white blood cell count above normal is called:
A. Leukopenia
B. Leukocytosis
C. Thrombocytopenia
D. Polycythemia
Correct Answer: B
Leukocytosis means an increased leukocyte count.
CSS - PMS - CCE - PCS - General Science
Blood System
Engulfment of microbes by certain white blood cells is called:
A. Agglutination
B. Phagocytosis
C. Erythropoiesis
D. Hemoconcentration
Correct Answer: B
Phagocytosis is the ingestion and destruction of particles or microorganisms by cells such as neutrophils and macrophages.
CSS - PMS - CCE - PCS - General Science
Blood System
Movement of leukocytes toward a chemical signal is called:
A. Chemotaxis
B. Hemostasis
C. Hematocrit
D. Hemolysis
Correct Answer: A
Chemotaxis is directed cell movement along a chemical concentration gradient.
CSS - PMS - CCE - PCS - General Science
Blood System
The movement of white blood cells through intact capillary walls is called:
A. Hemolysis
B. Diapedesis
C. Agglutination
D. Osmosis
Correct Answer: B
Diapedesis is the passage of leukocytes through vessel walls into tissues.
CSS - PMS - CCE - PCS - General Science
Blood System
Natural killer cells are best known for their ability to:
A. Carry oxygen
B. Kill certain virus-infected and tumor cells
C. Produce fibrinogen
D. Synthesize albumin
Correct Answer: B
Natural killer cells can destroy some infected or transformed cells without prior antigen-specific sensitization.
CSS - PMS - CCE - PCS - General Science
Blood System
T lymphocytes are especially important in:
A. Cell-mediated immunity
B. Hemoglobin synthesis
C. Fibrin formation only
D. Iron transport
Correct Answer: A
T cells are central to cell-mediated immune responses and immune regulation.
CSS - PMS - CCE - PCS - General Science
Blood System
B lymphocytes are especially associated with:
A. Antibody production
B. Oxygen transport
C. Primary clot formation
D. Bilirubin synthesis
Correct Answer: A
Activated B lymphocytes can differentiate into plasma cells that secrete antibodies.
CSS - PMS - CCE - PCS - General Science
Blood System
Monocytes that enter tissues commonly differentiate into:
A. Erythrocytes
B. Macrophages
C. Platelets
D. Megakaryocytes
Correct Answer: B
Circulating monocytes can migrate into tissues and become macrophages or related phagocytic cells.
CSS - PMS - CCE - PCS - General Science
Blood System
Basophils contribute to allergic responses by releasing mediators including:
A. Hemoglobin
B. Histamine
C. Bilirubin
D. Erythropoietin
Correct Answer: B
Basophils can release histamine and other inflammatory mediators during hypersensitivity reactions.
CSS - PMS - CCE - PCS - General Science
Blood System
Eosinophil granules commonly stain strongly with:
A. Acidic eosin dye
B. Basic methylene blue only
C. Silver salts only
D. No stain
Correct Answer: A
Eosinophil granules have affinity for the acidic dye eosin and appear reddish-orange.
CSS - PMS - CCE - PCS - General Science
Blood System
The multilobed nucleus is characteristic of:
A. Mature neutrophils
B. Red blood cells
C. Platelets
D. Plasma cells only
Correct Answer: A
Mature neutrophils have a segmented, multilobed nucleus.
CSS - PMS - CCE - PCS - General Science
Blood System
Which leukocytes are classified as agranulocytes?
A. Neutrophils and basophils
B. Eosinophils and neutrophils
C. Lymphocytes and monocytes
D. Platelets and monocytes
Correct Answer: C
Lymphocytes and monocytes are classically grouped as agranulocytes.
CSS - PMS - CCE - PCS - General Science
Blood System
Which leukocytes are classified as granulocytes?
A. Neutrophils, eosinophils and basophils
B. Lymphocytes and monocytes
C. Erythrocytes and platelets
D. B cells and T cells only
Correct Answer: A
Neutrophils, eosinophils and basophils contain prominent cytoplasmic granules and are granulocytes.
CSS - PMS - CCE - PCS - General Science
Blood System
Which white blood cell is usually the least numerous in normal blood?
A. Neutrophil
B. Basophil
C. Lymphocyte
D. Monocyte
Correct Answer: B
Basophils are normally the least common circulating leukocyte type.