Haemotology 3 - WBCs Flashcards
what is the most abundant WBC?
Neutrophils (50-70% of WBCs)
general term for WBCs
leukocytes
name the 5 types of leukocytes
Neutrophils
Eosinophils
Basophils
Lymphocytes
Monocytes
least abundant leukocyte?
Basophils
what is the common cell that forms 4 of the leukocytes
common myeloid progenitor (which then forms the myeloblast, then basophils, neutrophils, eosinophils and monocytes)
name the common cell that produces lymphocytes
common lymphoid progenitor
main defining feature of leukocytes
has a nucleus
key general roles of WBCs
defend against pathogens
toxin and waste removal
remove damged cells (e.g. RBCs)
common features of all leukocytes: extravasation
can squeeze between endothelial cells to enter surrounding tissue
basically, can migrate out of bloodstream
via process called DIAPEDESIS
common features of all leukocytes: amoeboid movement
develops projections using the cytoplasm to form pseudopodia
psuedopodia are like little legs
use it to move through endothelial lining out of bloodstream into tissues
so it assists extravasation
not only in wbcs, but in others as well
common features of all leukocytes: chemical stimuli
all respond to different chemical stimuli
can also give off chemical stimuli to attract other cells
POSITIVE CHEMOTAXIS
common features of all leukocytes: phagocytosis
only neutrophils, eosinophils and monocytes can do it
what is the normal WBC count range
4-11 x 10^9 /litre blood
no. in blood often an indicator of disease
which of the 5 are granulocytes
neutrophils
eosinophils
basophils
which of the 5 are agranulocytes
lymphocytes
monocytes
what is the ratio of RBC:Platelets:WBCs ?
700:40:1
NEUTROPHILS: structure
make up 50-70% of WBCs
9-15micrometers in diameter
distinctive nucleus 2-5 lobes (more lobes = more mature), granular cytoplasm
NEUTROPHILS: function
first line of defence against BACTERIAL infection
phagocytic
mobile, can move from circ system into tissues
this means
they only circulate in blood for ~10hrs before they either migrate into tissue or are broken down
major constituent of pus - made up of WBCs that were invloved in fighting the infection
what might be the reason for less than 2 lobes in a neutrophil OR more than 5?
more than 5 = abnormal
less than 2 = immature, been released to early
can happen when body overwhelmed by infection
or in malignancy
EOSINOPHILS: structure
2-4% of WBCs
10-12micrometers
bilobed nucleus - sunglasses
stains red
EOSINOPHILS: function
release toxic compunds (e.g. NO and cytotoxic enzymes)
combat parasitic infection
can also help other cells out by attacking bacteria etc.
involved in allergies&asthma - often have increased eosinophil count
circulate in blood approx 8-12 hrs before they migrate to tissue or destroyed
short lifespan - 1-3 days
what might an irregular shape of an eosinophil indicate
theyr’re reacting to some kind of pathogen
may have eosinophilia (too many)
BASOPHILS: structure
> 1% of WBC - only time you’ll see more is in large inflammatory response or in some haemtological malignancy
8-10micrometers
bilobed ‘S’ shaped nucleus
but hard to see cuz large granules
can look similar to lymphocytes
granules = histamine, heparin
BASOPHILS: function
inflammatory response
lifespan is unknown
may be precursors to mast cells
MONOCYTE : structure
2-10%
fucking huge
up to 20micrometers
large kidney shaped nucleus (got indentation in nucleus)
extensive cytoplasm
MONOCYTE: function
little function in blood - mainly in tissues
(usually in spleen- help digest RBCs)
migrate out of circulation after 3-4 days
tissue macrophages live for months-years
phagocytic
LYMPHOCYTE: structure
20-30%
smalles WBC
6-15micrometers - depends on type of lymphocyte
lifespan = weeks to several years
large nucleus compared to cytoplasm
LYMPHOCYTE: function
central role in immunological defense
circulate between various lymphoid tissues and other tissues via blood and lympahtic vessels
Types of lymphocytes
T cells
B cells
Natural killer cells
T cells function
cell-mediated immunity
e.g. invloved in transplant rejection
B cells function
differentiate further into plasma cells
secrete antibodies (humoral immunity)
Natural killer cells - function
immune surveillance
inmportant in preventing cancer
if someone has viral infection, which WBC count is raised
lymphocyte
