Cell Histology Flashcards
what are the 3 broad types of blood cells and their functions
Red blood cells - transport O2
White blood cells - fight infection
Platelets- prevent bleeding
what is haemopoeisis
production of blood cells
what are blood cells derived from
pluripotent stem cells
sites of haemopoeisis in the embryo
Yolk sac, then liver then bone marrow
3rd-7th month gestation- spleen
sites of haemopoeisis at birth
mostly bone marrow
liver and spleen when needed
sites of haemopoeisis in an adult
bone marrow of skull, ribs, sternum, pelvis, proximal ends of femur
Describe the divisions to mature cells in the haemopoietic tree
Stem cells – multipoint progenitors – oligolineage progenitors – mature cells
Name the 2 oligolineage progenitors
CMP- common myeloid progenitor
CLP- common lymphocyte progenitor
what does CMP stand for? what is it?
Common myeloid progenitor
it is an oligolineage progenitor in the haemopoietic tree
what does CLP stand for? what is it?
Common lymphocyte progenitor
It is an oligolineage progenitor in the haemopoietic tree
what is the progression of precursor to mature cell for neutrophils
myeloblast to premyelocyte to myelocyte through metamyelocute forms eventually to neutrophils
what is erythropoiesis
red blood cell production
what is the progression of precursor to mature cell for RBCs
- pronormoblast
- basophilic/early normoblast
- polychromatophilic/intermediate normoblast
- orthochromatic/late normoblast
- reticulocyte
- mature red cell/erythrocyte
what happens during the different stages of erythropoiesis
size drops as cells mature
once they have Hb in the cell they begin carrying oxygen
reticulocyte are the first cell to be seen in the blood stream
Previous cell types are only found in the bone marrow
what cell in the blood stream can show how active the bone marrow is
the number of reticulocytes
what key step occurs between the orthochromatic and reticulocyte stage
loss of nucleus and RNA
how does a reticulocyte and a RBC differ in appearance
reticulocyte stains slightly blue due to left over RNA still present
what is the precursor for platelets
megakaryocyte
what are the different types of white blood cells
granulocytes
monocytes – become macrophage
lymphocytes – T + B cells
why are granulocytes named the way they are
Contain granules
Named according to their uptake on stains
name the 3 types of granulocytes
eosinophils (red)
basophils (blue-black)
Neutrophils (don’t take up a colour- neutral)
structure of neutrophils
Segmented nucleus (polymorph)
function of neutrophils
phagocytose invaders
Kill with granule contents + die in the process
Attract other cells
what increases the number of neutrophils in the blood
Body stress- e.g. infection, trauma, infarction
structure of eosinophils
Usually bi-lobed
Red granules
function of eosinophils
fight parasitic infections
Involved in hypersensitivity
Elevated in patients with allergic conditions
structure of basophils
large deep purple granules obscuring nucleus
functions of basophils
circulating version of mast cell
mediates hypersensitivity reactions
Fc receptors bind IgE
Granules contain histamine
what are monocytes the precursors of
macrophages
structure of monocytes
large single nucleus
function of monocytes
Circulate for a week and enter tissues to become macrophage- phagocytose invaders
Attract other cells
More long lived than neutrophils
structure of lymphocytes
Mature: small with condensed nucleus and rim of cytoplasm Atypical: large with plentiful blue cytoplasm
what investigations can be done to assess the primitive precursors
Immunophenotyping- expression profile of proteins (antigens) on the surface of cells
Bio-assays- culture in vitro and show lineage of progrency in different growth conditions
common site of bone marrow biopsies as it is quite active
Posterior iliac crests
causes of neutrophilia
bacterial infection/inflammation
causes of lymphocytosis
viral infection
pertussis
childhood response to infection
what does the presence of immature neutrophils (myelocytes) in the blood indicate
stress/damage to the marrow
what can cause a basophilia
chronic myeloid leukaemia
polycythaemia rubra vera
what can cause an eosinophilia
allergy asthma parasitic infection hodgkin lymphoma eosinophilic pneumonia
what is a marker of mast cell degranulation/excess mast cell numbers
tryptase
what is malignant proliferation of mast cells called
systemic mastocytosis
what can cause a monocytosis
malignancy
chronic bacterial infections
connective tissue disease
what may be seen in smokers
mild neutrophilia
what causes infective mononucleosis
EBV
