W1 LECT 3: Leucocytes Flashcards
what is the basic functions of WBC’S?
- Immune defense
- immune surveillance
- regulatory of the immune response
- antigen presentation
- inflammation
- wound healing
types of wbc’s? and classification?
Myeloid”
or marrow cells
(innate immune system)
Granulocytes:
-Neutrophils, Eosinophils, Basophils, Monocytes/
macrophages
Lymphoid cells
(innate and adaptive
immune system)
* B lymphocytes
* T lymphocytes,
CD4 and CD8
* NK cells
name all the stages of neutrophil maturation
blast, promyelocyte, myelocyte, metamyelocyte, band cell, mature neutrophil
explain the life cycle of neutrophils
-function in inflammation
-neutrophils from the bone marrow will be transported to bloodstream in response to pathogens
- it will travel into the bloodstream until
- chemokines cause the cells to be rested to pass through the tissue wall
- it will locate the pathogen and kill it by phagocytosis or by nets
control of neutrophil activity
extensive network of receptors*
- Growth factors
- opsonins
- chemotaxins
- other inflammatory mediators
what are the 2 types of granules seen in neutrophils?
Primary: formed in
the promyelocyte
* Secondary/specific
and tertiary:
formed in the
myelocyte and
metamyelocyte
what are the neutrophil antimicobial mechanism?
the radicals*
Oxygen-Dependent
* Superoxide anion O2–
* Hydrogen peroxide H2O2
* Hydroxyl radical HO
* Singlet oxygen 1O2
* N-chloramines R-NHC1, R-NCl2
* Hypohalous acids HO-X
Nitrogen-dependent
* Nitric oxide NO
* Peroxynitrite ONOO–
why are neutrophils packaged into granules?
The packaging of these granules within neutrophils allows for rapid deployment of their contents upon activation
what are the neutrophil antimicrobial mechanisms?
- arachidonate metabolites
- lysozyme
- lysosomal proteases
- lactoferrin
- cationic proteins
what is the neutrophil pool?
The neutrophil pools
1. Mature neutrophils in the marrow
2. Circulating neutrophils:
marginating
free flowing
3. Sequestered in the spleen
4. In the tissues
what is the classification of nuetrophil disorders?
- qualitative: inherited, acquired
- quantitative: increased, decreased
what are the examples of quantitative changes
Neutrophilia
* Increased
synthesis
* Mobilisation of
unmeasured
pools
Neutropenia
* Decreased
synthesis
Increased
destruction/
sequestration
what is the eosinophil lifecycle?
Circulate for about 18 hours
* Most go to the gut. Emigration into the tissues
is initiated by selectin/ligand pairing on the
endothelium
* Thought to be quite long-lived in the tissues
with most loss occurring by migration into the
gut or alveolar lumen.
* Apoptosis occurs in the lumen
function of eosinophils?
- killing parasites
- allergy
outline basophils?
-Least common of the
granulocytes
* Not normally seen in
tissues – recruited in
cases of inflammation
* IgE receptors
* Contain mediators of
immediate
hypersensitivity reactions
such as histamine
