Intro* Flashcards
what is the production of blood cells called
haemopoiesis or haematopoiesis
where do blood cells come from
small pool of pluripotent stem cells capable of making all the different types of blood cells
embryo sites of haematopoiesis
yolk sac then liver
from 3rd to 7th month - spleen
sites of haematopoiesis at birth
mostly bone marrow
liver and spleen when needed
sites of haematopoiesis - birth to maturity
number of active sites in bone marrow decreases but retain ability for haematopoiesis
sites of haematopoiesis - adult
bone marrow of skill, ribs, sternum, pelvis, proximal ends of femur
haematopoietic stem cells turnover approx
100 million red blood cells /min
60 mill neutrophils/min
150 mill platelets/min
what do red blood cells do
carry oxygen
buffer co2 etc
what do platelets do
stop bleeding
what do white cells do
fight infection
cancer prevention etc
process of erythropoiesis
in bone marrow: pronormoblast basophillic/early normoblast polychromatophillic/intermediate normoblast orthochromatic/late normoblast
in blood stream:
reticulyte
mature red cell/erythrocyte
how are platelets former
budd of the periphery of megakaryocytic
which doesn’t split however the nucleus does divide
neutrophils functions
short life in circulation - transit to tissue
phagocyte invaders
kill with granule contents and die in the process
attract other cells
increased by body stress - infection, trauma, infarction
fine granulation which imparts a lilac hue to the cytoplasm
neutrophils
function of eosinophils
fight parasitic infections
involved in hypersensitivity reactions - allergy
often elevated in px with allergic conditions
red orange globular granules in cytoplasm
eosinophils
function of basophils
circulating version of tissue mast cell
mediates h/s reaction
Fc receptors bing IgE
granules contain histamine
function of monocytes
circulate for a week and enter tissue to become macrophages
phagocyte invades - kill them, present antigen to lymphocytes
attract other cells
live longer than neutrophils
function of lymphocytes
numerous types and functions
cognate response to infection
the brains of the immune system
what do atypical lymphocytes suggest
intercurrent often viral infection e.g. EBV
how can primitive precursors be recognised
immunophenotyping - expression profile of proteins (antigens) on the surface of cells
nil-assays - culture in vitro and show lineage of progeny in different growth conditions
how to examine the haemopoietic system
look at the peripheral blood
look at the ben marrow
specialised tests of bone marrow
look at other sites of relevance to blood production - splenomegaly, hepatomegaly, lymphadenopathy
where is bone marrow inspected from
posterior iliac crests are common sites for bone marrow aspiration and biopsy
