WBCs Flashcards
types of phagocytes
granulocytes
- neutrophils
- basophils
- eosinophils
monocytes
regulation of neutrophils
haematopoietic growth factors
e.g. IL3, stem cell factor, G-CSF
life cycle of neutrophils
- from marrow haematopoietic stem cell –> myeloblast
- 7-10 day maturation in marrow
- circulates 6-10 hours, then into tissues to phagocytose
clinical importance of G-CSF
filgrastin
- target given to patients having chemotherapy to reduce neutropenia
function of neutrophils
- chemotaxis to sites of damage, infection
- phagocytosis of foreign antigens
- destruction of bacteria by oxidative and non-oxidative means
monocyte life cycle
- shares precursors with neutrophils
- 7-10 day maturation in marrow
- 1-3 days circulating in blood
- enters tissue = macrophage
- liver = kupffer cells
- lung = alveolar cells
- skin = langerhans cells
function of monocytes
mainly seen in chronic infections
phagocytosis
- chemotaxis to site
- opsonisation
- phagocytosis
synthetic function of monocytes
- complement
- interferons
- cytokines (TNF, IL-1)
- growth factors
- PG
as well as antigen presentation
structure and function of basophils
- IgE binding sites
- related to mast cells
- contain histamine granules
- induces features of allergy, hypersensitivity reactions
different functions of lymphocytes
B cells –> plasma cells (produce antibodies)
T cells = cell-mediated immunity
- CD4 T helper cells - CD8 T cytotoxic cells
lymphoid maturation and migration
all lymphocytes are bone marrow derived
maturation occurs in primary lymph organs
- B cells = bone marrow - T cells = thymus
migration to secondary lymph tissues
- e.g. lymph nodes, spleen etc
lymphopenia
HIV infection (CD4 helper T cells lost)
congenital immune defects
sever bone marrow failure
lymphocytosis
reactive = viral infection (EBV)
malignant = CLL
lymphadenopathy
reactive = viral infection, local bacterial infection
malignant = lymphoma, metastatic spread
