HAEMOPOIESIS Flashcards
1
Q
what is haemopoiesis
A
production of blood cells from a pool of pluripotent stem cells capable of making all different types of blood cells
2
Q
what is the site of haemopoiesis in an embryo
A
yolk sac then liver then marrow
spleen
3
Q
when does the spleen become a site for haemopoiesis in the embryo
A
3rd to 7th month
4
Q
what is the site of haemopoiesis at birth
A
mostly bone marrow
liver and spleen when needed
5
Q
what is the site of haemopoiesis in children
A
mainly long bones of limbs
6
Q
as you grow the number of active sites in bone marrow for haemopoiesis increases/decreases
A
decreases
7
Q
as you grow, ____ bone marrow is replaced with ___ bone marrow
A
red marrow replaced with yellow marrow
8
Q
when you are born what bones have red marrow and are involved in haemopoiesis
A
all
9
Q
what is the site of haemopoiesis in adults
A
bone marrow of skull, ribs, sternum, pelvis, proximal ends of femur (axial skeleton)
10
Q
what layer do haemopoietic stem cells originate
A
mesoderm
11
Q
what is meant by differentiation of a stem cell
A
development of features of a specialised end cell population from stem cell
12
Q
stem cells are capable of ____
A
self renewal
13
Q
most stem cells are active
true/false
A
false
most sit in a quiescent state
14
Q
what organelles do fully differentiated red blood cells lack
A
nucleus
mitochondria
15
Q
what is the formation of granulocytes called
A
granulopoiesis
16
Q
what cells are part of the myeloid lineage
A
red blood cells granulocytes platelets monocytes mast cell
17
Q
from what cells do granulocytes develop
A
myeloblasts
18
Q
when does haemoglobin begin to be produced in the development of RBCs
A
polychromatophilic / intermediate normoblast
19
Q
at what point in the development of RBCs does the nucleus shrink and all haemoglobin present
A
orthrochromatic / late normoblast
20
Q
when is the nucleus extruded in the development of RBCs
A
orthochromatic / late normoblast —> reticulocyte
21
Q
what makes reticulocyte polychromatic
A
contains RNA
22
Q
from what cells are platelets derived
A
megakaryocytes
23
Q
how are platelets formed
A
budding from megakaryocytes
24
Q
what is the lifespan of a platelet
A
7 - 10 days
25
what is the nucleus of a megakaryocyte like
lobulated
26
what are the 3 types of granulocyte
eosinophils
basophils
neutrophils
27
what are granulocytes names based on
the dye they take up - eosin or basic dye
28
granulocytes contain ___ that are easily visible on light microscope
granules
29
what can be used to tell blood cell precursors apart
immunophenotyping
| bio-assay
30
what is immunophenotyping
telling cells apart based on the antigen they express on their cell membrane - add a specific antibody with fluorescent tag which will bind to specific antigen - target cell will light up
31
what is a reticulocyte
immature red blood cell that circulates before maturing
32
what is marginisation
| name a drug that reduces it
process by which neutrophils leave the blood stream
| steroids
33
name 2 drugs that can cause agranulocytosis
carbimazole
| clozapine
34
what is the nucleus of a neutrophil like
multilobular segmented nucleus
35
what is another name for a neutrophil
polymorph
36
the granules of neutrophils are ____ stain
neutral
37
neutrophils have fine granulation and a ___ hue to the cytoplasm
lilac
38
neutrophils have a short/long life in circulation and then transit to ____
short
| tissues
39
what is the function of a neutrophil
phagocytose invaders - APC
attract other cells
acute inflammation
40
how do neutrophils kill other cells
phagocytosis - kill with granule contents and die in process
41
in what situations would neutrophil count be raised
infection
trauma
infarction
42
what is the nucleus of an eosinophil like
bi-lobed / horse shoe shaped
43
what colour are the granules in eosinophils
bright red-orange
44
what is the function of eosinophils
fight parasitic infections
| involved in hypersensitivity allergic reactions
45
what are 2 conditions in which you would see raised levels of eosinophils
asthma
| atopic rhinitis
46
what is the name of the vasculitis that shows raised eosinophils
Eosinophilic Granulomatosis with polyangitis
47
describe the granules of basophils
purple/blue-black granules overlying the nucleus
48
basophils are a circulating version of ____
tissue mast cells
49
basophils are common/uncommon in circulation
uncommon
50
give 2 conditions in which basophils may be raised
CML
| PRV
51
when basophils degranulate what do they release
histamine
52
what do the Fc receptors of basophils bind to
IgE
53
what is the cell that is a precursor to macrophages
monocyte
54
what is the nucleus of a monocyte like
large single nucleus - kidney bean shaped
55
what are the granules of monocytes like
faintly staining, often vacuolated
56
what colour is the cytoplasm of a monocyte
large pale blue cytoplasm
57
monocytes have the same lineage as ____
granulocytes
58
how long do monocytes stay in circulation before entering tissues to become macrophages
1 week
59
what is the function of monocytes
phagocytose invaders - APC
| attract other cells
60
are monocytes or neutrophils more long lived
monocytes
61
what are some conditions where neutrophil count would be rasied
chronic bacterial infection
SLE, RA
lymphoma / leukaemia
62
describe the structure of a mature lymphocyte
small with condensed nucleus and rim of cytoplasm
| - nucleus has areas of condensed / clumped chromatin
63
what is an atypical lymphocyte
activated
64
describe an atypical/activated lymphocyte
large with plentiful blue cytoplasm extending around neighbouring red cells on the film
- nucleus more open structure
65
what are the sub-types of lymphocytes
B T and NK
66
what is a condition where atypical lymphocytes can be seen
glandular fever
67
what is a bio-assay
culture in vitro and show lineage of progeny in different growth conditions
68
what is automated cell counting
looks at physical principles e.g. cell size and light scattering properties
69
what is the site of bone marrow aspiration and biopsy in adult
PSIS
| or sternum
70
what kind of needle is used to obtain a core biopsy from bone marrow
jamshidi needle
71
do platelets have a nucleus
no
72
what is the role of monocytes
modulate immune reactions
73
what is the function of B cells
humoral immunity
74
what is the function of T cells
cell mediated immunity and regulatory functions
75
what is the function of NK cells
anti-viral / tumour
76
what is the life span of a RBC
120 days
77
what is the lifespan of a neutrophil
7-8 hours
78
what cell becomes deficient first in bone marrow suppression
neutrophils
79
megakaryocytes are ___ploid
poly
80
what is a myelocyte
nucleated precursor between neutrophils and blasts
81
what is meant by self renewal
one of the daughter cells will be a haemopoeitic stem cell identical to the mother cell - can divide forever
82
give 5 steps in haemopoiesis
```
self renewal
proliferation
differentiation
maturation
apoptosis
```
83
can proliferation and maturation occur at the same time
yes
84
stem cells are active/dormant during steady state haemopoiesis
dormant
85
circulating committed progenitors are detectable as early as week _
5
86
what is the first site of erythroid activity
yolk sac
87
when does the yolk sac cease to be a site of erythroid activity
week 10
88
the liver starts as a site of erythroid activity at week _
6
89
the bone marrow starts as a site of erythroid activity by week _
16
90
what is the site of bone marrow biopsy in a child
anterior tibia
91
what are the 3 compartments of the bone marrow
cellular
connective tissue matrix
vascular elements
92
what are the 2 divisions of the cellular compartment of the bone marrow
haemopoietic cells
| non-haemopoietic cells
93
what are the 4 types of non-haemopoietic cells
adipocytes
fibroblasts
osteoclasts
osteoblasts
94
in the bone marrow, arterioles drain into _____ which open into larger ____ ____
sinuses
| central sinuses
95
what are 2 differences between sinuses and capillaries
sinuses are larger and have a discontinuous basement membrane
96
what is the purpose of the discontinuous basement membrane of sinuses
allows formed blood cells to enter circulation
97
what are the gaps in the basement membrane called
fenestrations
98
what changes to the sinuses are associated with the release of RBCs
sinusoidal dilatation
| increased blood flow
99
what cells actively migrate towards the sinusoid
neutrophils
100
what cells contain smooth muscle - dilate and constrict to increase or decrease blood flow
adventitial cells
101
megakaryocytes extend what into the sinusoidal blood vessels
long branching processes called proplatelets
102
what is meant by the term "red marrow"
haemopoietically active
103
what is meant by the term "yellow marrow"
fatty and inactive
104
marrow cellularity is increased / decreased with age
decreased
105
what is the myeloid : erythroid ratio
relationship between neutrophils and precursors to the proportion of nucleated red cell precursors
106
what is a normal range of myeloid : erythroid ratio
1.5:1 to 3.3:1
107
give an example when the myeloid : erythroid ratio would be reversed as a compensatory response
haemolysis
108
what 3 things regulate haemopoiesis
intrinsic properties of cells
micro-environmental factors
specific anatomical area (niche)
109
what does erythropoietin respond to
hypoxia
110
what regulates neutrophil precursor maturation
G-CSF (granulocyte - colony stimulating factor)
111
what regulates growth and development of megakaryocytes from precursors
thrombopoietin
112
erythroid islands nurse ____
macrophages
113
describe the microenvironmental regulation of haemopoiesis
the niche occupied by haemopoietic stem cells is around vasculature (arteriole or sinusoid) and provides access to different signals (cytokines)
114
when can a niche be altered
diseased states or with therapy
115
how do we assess non-lymphoid mature cells
blood count / morphology
116
how do we assess lymphoid cells
immunophenotyping
117
how do we assess precursor cells
bone marrow aspirate
118
are haemopoeitic progenitor/stem cells distinguishable
no - need immunophenotyping or bio assay or cytochemistry
