Haematology III-White Blood Cells Flashcards
what is the precursor of WBCs except lymphocytes
myeloblasts
what is a lymphoid progenitor
precursor of lymphocytes
what are the different types of lymphocytes?
B, T and natural killer
what is another name for wbcs?
leukocytes
what does the nucleus of wbcs allow them to do
capability of repair and allows them to remain in the tissue longer
what are the arm like features of wbcs? what is their function?
pseudopodia
aids movement in tissues
what are the 3 roles of WBCs ?
defense vs pathogens
toxin and waste removal
remove damaged cells
where do wbcs mainly act?
outside in tissues- in transit between sites of activity
Diapedesis
movement into tissue through blood vessel walls
what movement are all wbcs capable of?
amoeboid movement
what stimuli are wbcs attracted to?
specific chemical stimuli
Which wbcs are phagocytes?
neutrophil, eosinophils and monocytes
which wbcs are granulocytes?
neutrophils, eosinophils and basophils
granulocytes
contain granules in cytoplasm
agranulocytes
no visual granules under microscope
which wbcs are agranulocytes
monocytes and lymphocytes
what is the normal wbc count in blood
approx 4-11 x 109 /litre blood
what could an over production of wbcs indicate?
signs of leukaemia
what is the ratio of RBCs: platelets : WBCs
700 : 40 : 1
which type of WBC is the most common?
neutrophils
what percentage of WBCs are neutrophils
50-70%
diameter of neutrophils
9-15µm diameter (12 µm)
lobes of neutrophil nucleus
2-5 lobes (lobes related to maturity, the more mature, the more lobes )
function of neutrophils
first line of defence against bacterial infection
how long do neutrophils circulate in the blood
approx 10 hours
how long do neutrophils stay in tissue?
approx 10-12 days
what are neutrophils broken down by?
macrophages
what is pus composed of ?
combination of bacteria, chemical released by the bacteria and broken down wbcs
percentage of wbcs eosinophils make up
2-4%
diameter of eosinophils
10-12µm diameter
nucleus of eosinophils
Bilobular nucleus
functions of eosinophils
-Release toxic compounds, e.g. NO and cytotoxic enzymes
-Combat parasitic infections
-Also attack bacteria, protozoa, debris
how long do eosinophils circulate in the blood?
Circulate in blood approx. 8-12 hours migrate to tissues
how long do eosinophils last in tissues
Survive approx. 1-3 days
when may the count of eosinophils increase
Allergies, asthma
what does it show when wbcs shapes appear more abnormal
they are more activated
percentage of wbcs basophils make up?
<1% of WBC, least common
diameter of basophils
8-10µm diameter
nucleus of basophils
bilobed S shape nucleus
what do the granules of basophils secrete?
histamine and heparin
histamine
allergic response and inflammation (dilates blood vessels)
heparin
natural anticoagulant and helps prevent excessive clotting
function of basophils
Inflammatory response
why might basophils be precursors to mast cells?
share common bone marrow precursor and have similar clusters on their surface
in what disease is there an increase in basophils
leukaemia
what percentage of wbcs are monocytes
2-10%
diameter of wbcs
Up to 20µm diameter
nucleus of monocyte
Large kidney/horse shoe shaped nucleus,
cytoplasm of monocyte
Extensive cytoplasm
how long do monocytes stay in circulation
3-4 days
what type of macrophages are monocytes
tissue macrophages
how long do monocytes stay in tissues
several months to years
what percentage of wbcs do lymphocytes make up
20-30%
diameter of lymphocytes
6-15µm diameter
lifespan of lymphocytes
weeks to several years
function of lymphocytes
central role in all immunological defense mechanisms
Circulate between various lymphoid tissues and all other tissues of body via blood and lymphatic vessels
T lymphocyte
mediate cell-mediated immunity (e.g. transplant rejection)
B lymphocytes
differentiate into plasma cells; secrete antibodies (humoral immunity)
Natural Killer cells
“immune surveillance” - important in preventing cancer
