Blood Cells - Heamtology Foundation.docx

+-----------------------+-----------------------+-----------------------+ | **Erythrocytes** | | | +=======================+=======================+=======================+ | | **[Function]{.underli | | |...

+-----------------------+-----------------------+-----------------------+ | **Erythrocytes** | | | +=======================+=======================+=======================+ | | **[Function]{.underli | | | | ne}** | | | | | | | | \- Carry O2 to | | | | tissues and CO2 to | | | | lungs. | | | | | | | | **[Shape] | | | | ** | | | | | | | | \- Anucleate and lack | | | | organelles; biconcave | | | | A , with large | | | | surface | | | | area-to-volume ratio | | | | for rapid gas | | | | exchange. | | | | | | | | **[Characteristics]{. | | | | underline}** | | | | | | | | \- Life span of \~120 | | | | days in healthy | | | | adults; 60--90 days | | | | in neonates. | | | | | | | | \- Source of energy | | | | is glucose (90% used | | | | in glycolysis, 10% | | | | used in HMP shunt). | | | | | | | | \- Membranes contain | | | | Cl− /HCO3 − | | | | antiporter, which | | | | allow RBCs to export | | | | HCO3 − and transport | | | | CO2 from the | | | | periphery to the | | | | lungs for | | | | elimination. | | | | | | | | **[Terminology]{.unde | | | | rline}** | | | | | | | | \- Erythrocytosis = | | | | polycythemia = | | | | increased Hct. | | | | | | | | \- Anisocytosis = | | | | varying sizes. | | | | | | | | \- Poikilocytosis = | | | | varying shapes. | | | | | | | | \- Reticulocyte = | | | | immature RBC; | | | | reflects erythroid | | | | proliferation. | | | | | | | | \- Bluish colour | | | | (polychromasia) on | | | | Wright-Giemsa stain | | | | of reticulocytes | | | | represents residual | | | | ribosomal RNA. | | +-----------------------+-----------------------+-----------------------+ | **Monocytes** | | | +-----------------------+-----------------------+-----------------------+ | | \- Found in blood, | | | | differentiate into | | | | macrophages in | | | | tissues. | | | | | | | | **[Shape] | | | | **\ | | | | - Large, | | | | kidney-shaped nucleus | | | | A. Extensive | | | | "frosted glass" | | | | cytoplasm. | | +-----------------------+-----------------------+-----------------------+ | **Macrophages** | | | +-----------------------+-----------------------+-----------------------+ | | \- A type of | | | | antigen-presenting | | | | cell. | | | | | | | | \- Phagocytose | | | | bacteria, cellular | | | | debris, and senescent | | | | RBCs. | | | | | | | | \- Long life in | | | | tissues. | | | | | | | | \- Differentiate from | | | | circulating blood | | | | monocytes. | | | | | | | | \- Activated by | | | | IFN-γ. | | | | | | | | \- Can function as | | | | antigen-presenting | | | | cell via MHC II. | | | | | | | | \- Also engage in | | | | antibody dependent | | | | cellular | | | | cytotoxicity. | | | | | | | | \- Important cellular | | | | component of | | | | granulomas (eg, TB, | | | | sarcoidosis), where | | | | they may fuse to form | | | | giant cells | | | | | | | | **[Types of | | | | Macrophages]{.underli | | | | ne}** | | | | | | | | \- Kupffer cells in | | | | liver | | | | | | | | \- Histiocytes in | | | | connective tissue | | | | | | | | \- Osteoclasts in | | | | bone | | | | | | | | \- Microglial cells | | | | in brain | | | | | | | | **[Role in | | | | Sepsis]** | | | | | | | | \- Lipid A, is a | | | | component of the | | | | Lipopolysaccharide | | | | (LPS) found in the | | | | outer membrane of | | | | Gram-negative | | | | bacteria. | | | | | | | | \- When Lipid A binds | | | | to the CD14 receptor | | | | on macrophages, it | | | | activates these cells | | | | to release large | | | | amounts of | | | | pro-inflammatory | | | | cytokines. | | | | | | | | \- This response is | | | | crucial in fighting | | | | infections but can | | | | become overactive, | | | | leading to widespread | | | | inflammation and | | | | potentially severe | | | | outcomes like septic | | | | shock, characterized | | | | by a drastic drop in | | | | blood pressure and | | | | multiple organ | | | | failure. | | +-----------------------+-----------------------+-----------------------+ | **Megakaryocytes** | | | +-----------------------+-----------------------+-----------------------+ | | **Platelets** | | +-----------------------+-----------------------+-----------------------+ | | \- Involved in 1° | | | | hemostasis. | | | | | | | | \- Thrombopoietin | | | | stimulates | | | | megakaryocyte | | | | proliferation. | | | | | | | | \- Thrombocytopenia | | | | or decreased platelet | | | | function results in | | | | petechiae. | | | | | | | | **[Shape] | | | | ** | | | | | | | | \- Anucleate, small | | | | cytoplasmic fragments | | | | | | | | \- A derived from | | | | megakaryocytes. | | | | | | | | \- Life span of 8--10 | | | | days (platelets). | | | | | | | | **[Function]{.underli | | | | ne}** | | | | | | | | \- When activated by | | | | endothelial injury, | | | | aggregate with other | | | | platelets and | | | | interact with | | | | fibrinogen to form | | | | platelet plug. | | | | | | | | **[Contains]{.underli | | | | ne}**\ | | | | - Dense granules | | | | (Ca2+, ADP, | | | | Serotonin, Histamine) | | | | | | | | \- α granules (vWF, | | | | fibrinogen, | | | | fibronectin, platelet | | | | factor 4). | | | | | | | | \- Approximately 1/3 | | | | of platelet pool is | | | | stored in the | | | | spleen.\ | | | | **[Receptor/ | | | | Binder]** | | | | | | | | \- vWF receptor: | | | | GpIb. | | | | | | | | \- Fibrinogen | | | | receptor: GpIIb/IIIa. | | +-----------------------+-----------------------+-----------------------+ | **Lymphocytes** | | | +-----------------------+-----------------------+-----------------------+ | **B-Cell** | **T-Cell** | **NK-Cell** | +-----------------------+-----------------------+-----------------------+ | **[Function]{.underli | **[Function]{.underli | **[Function]{.underli | | ne}** | ne}** | ne}**\ | | | | - Important in innate | | \- Mediate humoral | \- Mediate cellular | immunity, especially | | immune response. | immune response.\ | against intracellular | | | - Differentiate into | pathogens. | | \- When antigen is | cytotoxic T cells | | | encountered, B cells | (express CD8, | \- They can | | differentiate into | recognize MHC I), | distinguish between | | plasma cells (which | helper T cells | healthy and abnormal | | produce antibodies) | (express CD4, | cells by detecting | | and memory cells. | recognize MHC II), | changes in cell | | | and regulatory T | surface proteins. | | \- Can function as an | cells. | | | APC. | | \- These changes can | | | **[Originate]{.underl | be induced by stress, | | **[Origin]{.underline | ine}** | malignant | | }** | | transformation, or | | | \- Stem cells in the | microbial infections. | | \- Stem cells in bone | bone marrow but | | | marrow and matures in | mature in the | \- NK cells are known | | marrow. | thymus.\ | for their ability to | | | **[Characteristics]{. | induce apoptosis | | \- Migrate to | underline}** | (programmed cell | | peripheral lymphoid | | death) in cells that | | tissue (follicles of | \- CD28 | lack class I MHC | | lymph nodes, white | (costimulatory | (Major | | pulp of spleen, | signal) necessary for | Histocompatibility | | unencapsulated | T-cell activation. | Complex) molecules. | | lymphoid tissue). | | | | | \- Most circulating | \- This feature is | | | lymphocytes are T | particularly | | | cells (80%). | important because | | | | many virally infected | | | | cells and tumor cells | | | | downregulate these | | | | molecules to evade | | | | immune detection. | | | | | | | | **[Shape] | | | | ** | | | | | | | | \- NK cells are | | | | larger than B and T | | | | cells. | | | | | | | | \- They contain | | | | cytoplasmic granules | | | | loaded with perforin | | | | and granzymes. | | | | Perforin forms pores | | | | in the target cell\'s | | | | membrane, allowing | | | | granzymes to enter | | | | and initiate | | | | apoptosis. | +-----------------------+-----------------------+-----------------------+ | **Plasma Cells** | **T-Helper Cells** | **Cytotoxic T- | | | | Cells** | +-----------------------+-----------------------+-----------------------+ | **[Function]{.underli | | | | ne}**\ | | | | - Produce large | | | | amounts of antibody | | | | specific to a | | | | particular antigen. | | | | | | | | **[Characteristics | | | | ]** | | | | | | | | \- A unique pattern | | | | seen in the nucleus | | | | of plasma cells, | | | | where the chromatin | | | | is arranged in a way | | | | that resembles a | | | | clock face. | | | | | | | | \- The nucleus of a | | | | plasma cell is | | | | typically off-center, | | | | which aids in the | | | | identification of | | | | these cells in | | | | microscopic images. | | | | | | | | \- They also have | | | | abundant rough | | | | endoplasmic reticulum | | | | (RER) which is | | | | necessary for the | | | | synthesis of the | | | | large amounts of | | | | protein (antibodies) | | | | that plasma cells | | | | produce. | | | | | | | | \- The well-rounded | | | | golgi apparatus in | | | | plasma cells is | | | | prominent and | | | | involved in the | | | | processing and | | | | packaging of | | | | antibodies before | | | | they are secreted. | | | | This apparatus is | | | | often highlighted in | | | | cell diagrams with | | | | arrows to show its | | | | prominence. | | | | | | | | **[Location]{.underli | | | | ne}** | | | | | | | | \- Found in bone | | | | marrow and normally | | | | do not circulate in | | | | peripheral blood. | | | +-----------------------+-----------------------+-----------------------+ | **Granulocytes** | | | +-----------------------+-----------------------+-----------------------+ | **Eosinophils** | **Neutrophils** | **Basophils** | +-----------------------+-----------------------+-----------------------+ | **[Function]{.underli | \- Acute inflammatory | **[Function]{.underli | | ne}** | response cells. | ne}** | | | | | | \- Defend against | \- Phagocytic. | \- Mediate allergic | | helminthic infections | Multilobed nucleus. | reaction. | | (major basic | | | | protein). | **[Specific Granules | **[Characteristics]{. | | | Contain:] | underline}** | | \- Packed with large | ** | | | eosinophilic granules | | \- Densely basophilic | | of uniform size A. | \- Leukocyte alkaline | granules A contain | | | phosphatase (LAP) | heparin | | \- Highly phagocytic | | (anticoagulant) and | | for antigen antibody | \- Collagenase\ | histamine | | complexes. | - Lysozyme | (vasodilator). | | | | | | \- Produce | \- Lactoferrin | \- Leukotrienes | | histaminase, major | | synthesized and | | basic protein (MBP, a | \- Azurophilic | released on demand. | | helminthotoxin), | granules (lysosomes) | | | eosinophil | contain proteinases, | \- | | peroxidase, | | Basophilic---stains | | eosinophil cationic | \- Acid phosphatase | readily with basic | | protein, and | | stains. | | eosinophil derived | -Myeloperoxidase | | | neurotoxin. | | **[Basophilia]{.under | | | \- β-glucuronidase. | line}** | | **[Shape] | | | | ** | **[Inflammatory | \- Uncommon, but can | | | states (eg, bacterial | be a sign of | | \- Bilobate nucleus. | infection) | myeloproliferative | | | cause:]** | disorders, | | **[Causes of | \ | particularly CML | | eosinophilia]{.underl | - Neutrophilia and | | | ine}**\ | changes in neutrophil | | | - Parasites | morphology, such as | | | | left shift,\ | | | \- Asthma | - Toxic granulation | | | | (dark blue, coarse | | | \- Chronic adrenal | granules), | | | insufficiency | | | | | \- Döhle bodies | | | \- Myeloproliferative | (light blue, | | | disorders | peripheral | | | | inclusions) | | | \- Allergic processes | | | | Neoplasia (eg, | \- Cytoplasmic | | | Hodgkin lymphoma) | vacuoles | | | | | | | \- Eosinophilic | **[Neutrophil | | | granulomatosis with | chemotactic agents: | | | polyangiitis | C5a]**, | | | | | | | | \- IL-8, LTB4, 5-HETE | | | | (leukotriene | | | | precursor) | | | | | | | | \- Kallikrein | | | | | | | | \- | | | | Platelet-activating | | | | factor, | | | | | | | | \- N-formylmethionine | | | | (bacterial proteins)\ | | | | - Hypersegmented | | | | neutrophils (nucleus | | | | has 6+ lobes) are | | | | seen in vitamin | | | | B12/folate | | | | deficiency. | | | | | | | | **[Left | | | | shift:]** | | | | | | | | \- Increased | | | | neutrophil precursors | | | | (eg, band cells, | | | | metamyelocytes) in | | | | peripheral blood. | | | | | | | | \- Reflects states of | | | | increased myeloid | | | | proliferation | | | | (eg, inflammation, | | | | CML). | | | | | | | | \- | | | | Leukoerythroblastic | | | | reaction---left shift | | | | accompanied by | | | | immature RBCs. | | | | | | | | \- Suggests bone | | | | marrow infiltration | | | | (eg, myelofibrosis, | | | | metastasis). | | +-----------------------+-----------------------+-----------------------+ | **Dendritic Cells** | | | +-----------------------+-----------------------+-----------------------+ | | \- Highly phagocytic | | | | antigen-presenting | | | | cells (APCs) A. | | | | | | | | **[Function]{.underli | | | | ne}** | | | | | | | | \- Function as link | | | | between innate and | | | | adaptive immune | | | | systems (eg, via | | | | T-cell stimulation). | | | | | | | | \- Express MHC class | | | | II and Fc receptors | | | | on surface. | | | | | | | | \- Can present | | | | exogenous antigens on | | | | MHC class I | | | | (cross-presentation). | | +-----------------------+-----------------------+-----------------------+ | **Mast Cells** | | | +-----------------------+-----------------------+-----------------------+ | | **[Function]{.underli | | | | ne}** | | | | | | | | \- Mediate local | | | | tissue allergic | | | | reactions. | | | | | | | | \- Contain basophilic | | | | granules. | | | | | | | | [Activators | | | | ] | | | | | | | | \- Tissue trauma, | | | | | | | | \- C3a and C5a | | | | | | | | \- Surface IgE | | | | cross-linking by | | | | antigen (IgE receptor | | | | aggregation) | | | | | | | | [Effect] | | | | | | | | \- Degranulation and | | | | release of histamine, | | | | heparin, tryptase, | | | | and eosinophil | | | | chemotactic factors. | | | | | | | | **[Origin]{.underline | | | | }** | | | | | | | | \- Originate from | | | | same precursor as | | | | basophils but are not | | | | the same cell type. | | | | | | | | \- Can bind the Fc | | | | portion of IgE to | | | | membrane. | | +-----------------------+-----------------------+-----------------------+