QUIZ 1

• Myeloblast: The first identifiable cell in the granulocytic series
• Marginating pool & Circulating pool: What are the two pools in which the peripheral blood circulation is divided?
• Diapedesis: What do you call the process of the movement of granulocytes from the circulating pool to the peripheral tissues?
• Phagocytosis: What functions does granulocytes particularly neutrophils carry out once they are on the peripheral tissues?
• 7-10 hours: The average life span of a segmented neutrophilic granulocyte in a circulating blood.
• 8.5 hours: Basophils have an average circulation time of how many hours?
• Charcot -Leyden crystals: If excessive number of eosinophils are present because of the disease state damaged or degenerated eosinophils give rise to these crystals found in the body secretions such as sputum and the stool.
• In the maturational sequence, enumerate the maturational series of the neutrophil.

  Myeloblast

  Promyelocyte

  Metamyelocyte

  Myelocyte

  Band neutrophil

  Segmented neutrophil
• Myeloblast: The earliest morphologically identifiable granulocytic precursor.
• Myeloblast: This cell has an average size of 10-18 um nuclear chromatin is finely reticular with 1-5 light staining  nucleoli. The cytoplasm appears as small ring of basophilic cytoplasm that lacks granules.
• Auer rods: Aggregates of fused lysosomes may appear as red, needle like crystalline cytoplasmic inclusions. These inclusions may appear alone or in groups. They are pathological.
• Promyelocyte: The outstanding feature of this cell is the presence of prominent granulation that may actually obscure the other morphological feature of the cell. The granules are primarily azurophilic and rich in enzymes myeloperoxidase and chloroacetate esterase.
• Myelocyte: This cell is characterized by recognizable occurrence of secondary or specific cytoplasmic granulation. The separate cell type: neutrophil, eosinophil, and basophil become visibly recognizable at this stage.
• Blue pink: Color of granules of neutrophils when stained with Wright’s stain.
• Orange: Color of granules of eosinophils when stained with Wright’s stain.
• Dark blue black: Color of granules of basophils when stained with Wright’s stain.
• Metamyelocyte: Its most characteristic feature is that the nucleus begins to assume an indented or kidney bean shape which will continue to elongate as the cell matures through this phase.
• Segmented neutrophil: It has a characteristic multilobed nucleus. The separate lobes are attached to each other by a fine thread like filament. The filament within separate lobes may be hidden.
• Mast cells: These cells are not observed in the blood of healthy persons. These cells have an appearance similar to that of the blood basophil and the surround are oval nucleus. The granules of this cell do not overlie the nucleus as they in basophils.
• Basophils: What granulocyte has granules that contain heparin and histamine?
• Polymorphonuclear cells (PMNs): This is the other term used to refer to neutrophils because of its nuclear segmentation that is quite prominent in its mature form.
• Kinetics: This refers to the movement of cells through developmental stages into the circulation and from the circulation to the tissues and includes the time spent in each phase of the cell’s life.
• G – CSF: The major cytokine responsible for the stimulation of neutrophil production.
• Kof: A paranuclear halo that is usually seen in normal promyelocytes.
• Dawn of neutrophilia: This term is used to describe early myelocytes that may look very similar to the promyelocytes in size and nuclear characteristics except that patches of grainy pink cytoplasm representing secondary granules begin to be evident in the area of the Golgi apparatus.
• Eosinophils: It is increased in infection by parasitic helminths and in vitro studies have found that it is capable of destroying tissue invading helminths through the secretion of MVP that ionic protein as well as the production of reactive oxygen species. There is also suggestion that it plays a role in preventing reinfection.
• Eosinophils: A hallmark of allergic disorders of which asthma has been best studied.
• Mast cells: They are tissue effector cells of allergic responses and inflammatory reactions. They are precursors that circulate in the peripheral blood for a brief period on their way to their tissue destinations. These cells have several phenotypic and functional similarities with both basophils and eosinophils. 
• Neutrophils share a common progenitor with monocytes and distinct from eosinophils and basophils, known as the granulocyte monocyte progenitor (GMP).
• Eosinophil development is similar to that described earlier for neutrophils, and evidence indicates that eosinophils arise from the CMP.
• Basophils are derived from progenitors in the bone marrow and spleen, where they differentiate under the influence of a number of cytokines, including IL-3 and TSLP (thymic stromal lymphopoietin)
• Cytokines: It mediate communication between the cells and exert their biological functions mostly through specific receptors expressed on the surface of the target cells. These signal substances have the capacity to stimulate, enhance, or suppress the proliferation of the stem and progenitor cells.
• STEM CELL POOL: Consists of HSCs that are capable of self-renewal and differentiation.
• PROLIFERATION (MITOTIC) POOL: Consists of cells that are dividing and includes (listed in the order of maturation) common myeloid progenitors (CMPs), also known as colony-forming units– granulocyte, erythrocyte, monocyte, and megakaryocyte (CFUGEMMs); granulocyte-monocyte progenitors (GMPs); myeloblasts; promyelocytes; and myelocytes.
• MATURATION (STORAGE) POOL: Consisting of cells undergoing nuclear maturation that form the marrow reserve and are available for release: metamyelocytes, band neutrophils, and segmented neutrophils.
• Promyelocyte: It has an average diameter of 14 to 20 μm. The nuclear chromatin is more condensed than in the blast, and nucleoli are present. The cytoplasm is a pale grayish blue.
• Myelocyte: it has an average diameter of 12 to 18 μm. The N:C ratio continues to decrease. The nucleus has a more oval appearance than in previous stages, nucleoli are no longer visible, and the chromatin is much more clumped than in previous stages.
• Fixed macrophages line the endothelium of capillaries and the sinuses, the bone marrow and organs, spleen, and lymph nodes.
• wandering cells: pulmonary alveolar macrophages, are the dust phagocytes of the lung and function as the first line of defense against inhaled foreign particles and bacteria.
• Acute inflammation is of short duration and is characterized by vascular and cellular changes.