White cells (4) Flashcards
What are the 3 granulocytes?
- basophil
- neutrophil
- eosinophil
How are granulocytes derived from multipotent haemopoietic stem cells?
HSCs–>myeloblasts–>granulocytes and monocytes
What are the myeloid growth factors?
- cause myeloid cells to go down certain pathways
- stimulated by infections or inflammatory state
- G-CSF= granulocyte colony-stimulating factor
- M-CSF= macrophage colony-stimulating factor (encourages production of monocytes, then macrophages)
- GM-CSF= granulocyte-macrophage colony-stimulating factor
What are characteristics of neutrophils?
- takes up basic and acidic stains in a neutral way
- survives only 7-20 hours in circulation before migrating to tissues
- segmented nucleus/lobulated
- main function: phagocytosis
What are characteristics of basophils?
- takes up basic dyes
- granules contain histamine and heparin (and proteolytic enzymss)
- involved in a variety of immune and inflammatory responses
What are characteristics of eosinophil?
- takes up eosin dye
- spends less time in circulation than neutrophils
- main function: defence against parasitic infection
How do neutrophils get recruited for phagocytosis?
- chemotaxis: cytokine produced that attracts neutrophils to migrate to tissue
- neutrophil becomes marginated/adheres to endothelium
- rolls along
- diapedesis: exit capillary wall
- migrate in tissues
- phagocytose bacteria/ dead cell
What are characteristics of monocytes?
- spend several days in circulation
- ingest bacteria and present their antigens on surface to lymphocytes
- migrate to tissues and develop into macrophages (which also ingest RBCs and store iron)
- largest of all leukocytes, w/ lobulated nucleus
What are the 3 types of lymphocytes?
B cells (mature into plasma cells), T cells and NK cells
What are characteristics of lymphocytes?
- can recirculate to lymph nodes and other tissues, then back to bloodstream
- intravascular life span= very variable, so can maintain immunological memory
Where does the plasma cell develop and what are some characteristics?
- in tissues
- produces antibodies
- more voluminous cytoplasm
- larger than other lymphocytes
- Golgi zone where antibody being produced= pale area
What kind of lymphocyte could it be if we can see cytoplasmic granules?
NK cell or cytotoxic T cell
What is the function of natural killer cells?
- part of innate immune system
- can kill tumour cells and virus-infected cells as they are foreign
What is leukocytosis?
too many white cells
- lymphocytosis
- monocytosis
- eosinophilia
- basophilia
- neutrophilia
What is leukopenia?
too few white cells
- usually neutropenia (bc most abundant)
- lymphopenia
What are causes of neutrophilia?
- infection esp. bacterial
- inflammation
- infarction (death of tissue) or other tissue damage
- myeloproliferative neoplasms (chronic myeloid leukaemia)
- normal feature in pregnancy
- normal after exercise (bc rapid shift from marginated pool to circulating pool)
- corticosteroid
What is toxic granulation?
heavy course granulation of neutrophils
What is left shift?
- things earlier in sequence are appearing in blood
- inc. in non-segmented neutrophils (band forms) or neutrophil precursors in blood
What are causes of neutropenia?
- normal in African ancestry
- chemotherapy and radio therapy
- autoimmune disorders (developed antibodies against own neutrophils)
- severe bacterial infections (all neutrophils rapidly leaving blood, faster than production)
- certain viral infections and drugs
What is neutrophil hypersegmentation?
- inc. in average number of neutrophil lobes/segments
- normal number is 3-5
- sign of B12 or folic acid deficiency
What can cause lymphocytosis?
- often in response to viral infection–> often ‘atypical lymphocytes’ e.g. infectious mononucleosis
- can result from leukaemia
What can cause lymphopenia?
- HIV infection
- chemotherapy
- radiotherapy
- corticosteroids
- severe infection
What are causes of monocytosis?
- chronic bacterial infection
- chronic inflammation
- some types of leukaemia
What are mononuclear cells?
monocytes and lymphocytes
What can cause eosinophilia?
- in response to parasitic infection or allergy: asthma, eczema, drugs
- can occur in leukaemia
What can cause basophilia?
leukaemia or related condition
