Blood cells Flashcards
4 elements of blood and their functions
red blood cells (erythrocytes) - transport oxygen from lungs to peripheral tissues
white blood cells (leukocytes) - destroy infecting organisms and remove dead/damaged tissues
platelets (thrombocytes) - adhere to defects in blood vessels
plasma - proteinaceous solution in which cells circulates. carries nutrients, metabolites, hormones, proteins etc
hemopoiesis
formation of cellular elements of the blood
bone marrow
most plasma proteins are made by the liver
staining of blood
thin smear on glass slide
names of white cells derived from stains used
Romanovsky stain applies several dyes with affinity for different constituents
mixed with coagulent
erythrocytes structure and histological appearance
6.5-8.5 um diameter biconcave pale in centre and darker at periphery acidophilia due to oxyhemoglobin no nucleus/organelles electron-dense cytoplasm
wax processed tissue and erythrocytes
appear smaller and biconcave shape isn’t discernable
metabolic activity of erythrocytes
anaerobic metabolism of glucose
ATP generation by hexose monophosphate shunt
movement of erythrocytes
highly deformable
able to squeeze down 3-4um diameter blood vessels
lifespan of erythrocytes
100-120 days
mature erythrocyte unable to synthesise new enzymes to replace those lost during metabolism
main factor in erythrocyte aging
diminishing efficiency of ion pumping mechanism
cells become less deformable until they can’t negotiate the splenic microcirculation
what organs dispose of erythrocytes?
spleen, liver and bone marrow
phagocytosis
spleen most active
what is the normal number of leukocytes in peripheral blood?
4-11 x 10^9/L
types of leukocytes and proportions
neutrophils 40-75%
eosinophils 5%
basophils 0.5%
lymphocytes 20-50%
monocytes 1-5%
why may proportions of leukocytes change?
requirement for increased activity in tissues
granulocytes
neutrophils, eosinophils and basophils
prominent granules
what may granulocytes also be called>
myeloid cells due to origin from bone marrow
what may neutrophils be called?
polymorphonuclear leukocyte/polymorphs due to multilobed nucleus
white blood cells
lymphocytes and monocytes
constituent of blood and originate from bone marrow
where are WBCs found?
lymph nodes, spleen
transformations in tissues
monocytes -> macrophages
basophils -> mast cells
erythrocyte cytoskeleton
filamentous skeleton of spectrin anchored to CM by band 3 protein, ankyrin, band 4 protein.
short actin pieces (15 actin monomers long) link spectrin to band 4 protein
neutrophil functions
circulate in resting state, enter tissue upon activation
become motile, phagocytic
ingest and destroy invading microorganisms
early stages of acute inflammatory response
what are neutrophils a major constituent of?
pus
how many neutrophils are normally in the blood?
1.5-10 x 10^9/L
neutrophilia
rise of neutrophils above 10 x 10^9/L
bacterial infection/tissue necrosis
