Hematopoesis Flashcards
1
Q
Where does blood formation occur mainly
A
bone marrow.
2
Q
Blood formation occurs mainly where
A
Bone marrow
3
Q
When does bone marrow Blood formation start
A
4th month IUL
4
Q
How is blood formed in 1-3 weeks of IUL
A
yolk sac:
5
Q
I’m the 4th week , where is blood formation
A
Liver
6
Q
For how long is blood formed in the liver and partly spleen
A
4th week up till 4th month
7
Q
When is blood formed in the bone marrow only
A
From 6th and 7th month
8
Q
For how long do all bones form blood
A
Form the 7th month of IUL ot 24 months afer birth;
9
Q
When does blood formation begin to Decrease from some bones in the body
A
2nd year
10
Q
What bones form blood throughout life
A
bone of base of skull,
ribcage,
the Vertebral column,
shoulder girdle
pelvic girdles:
11
Q
When does blood formation at long bones greatly reduce
A
18 years
12
Q
What’s a bone marrow
A
the tissue that occupies the space between opposing endosteal surfaces of a cavity bone.
13
Q
What’s the structure. within hte
bone marow.that’sresponsible for formation of blood
A
‘Hematopoietic Inductive :Microenvironment”’: (HIM)
14
Q
What blood vessels bring anterial blood to the bone
A
Nutrient artery
15
Q
Explain the process by which nutrient artery becomes emissary artery
A
NUTRIENT. ARTERY. Thsi artery pierces the bone in the nutrient artery canal. It then becomes hte medullaRy aftery, when the
artery enters into the marows space by dividing; into. ascencing/descending artery
medulany artery gives branches that traverse hte space of the bone marow. Theyare caled ThANSVERSE arteries- It pierced the endosteal surface to enter the bone cortex. Within the bone cortex, the
transverse artery pierced the haversion canal, and runs as haversian capillary .This haversion capillary supples oxygen to the cortical cells of the bone
The haversian capillary also turns: back into the bone marows! On entering the bone marow, it baloons out to form the bone marrow. sinussids: the blood si flowing: in the bone marow sinusoid and that blood comes to colect in the medullary vein (parallel to the medulary artery): The medulary vein collects and leaves the bone marow in the Emissary vein!
16
Q
Where are HIM found
A
Wishing the bone marrow sinusoids
17
Q
What forms the bone marrow sinusoids
A
The Haversian capillaries that turn into the bone marrow. And balloons our to form a sinusoid
18
Q
How does Haversian capillary come about
A
When the transverse artery pierced the endosteal surface of the bone, to enter the bone cortex and enters the Haversian canal, it becomes the Haversian capillary
19
Q
What cells make up the outer surface of the HIM
A
Endothelial cells
20
Q
What surface is the liminal and adluminal surface of the HIM
A
Luminal: outer surface
Adluminal: Inner surfaces
21
Q
What’s the HIM cavity called
A
hIM matrix
22
Q
What lines the adluminal surface of the HIM
A
Reticulum/Advantitia cells
Marrow stroma cells
Adipose cells
Macrophages
Some fibroblasts
23
Q
What’s the function of Reticulum/Adventitia cells
A
production of reticulin fibers that are secreted into the matrix tissue in the space of the HIM
24
Q
What’s the function of the fibroblasts and stroma cells
A
Produce varieties of collagen fibers, particularly collagen type I, III, and IV that are secreted in the HIMspace
25
What’s the cement tissue
Aminoglycans
26
Examples of cement tissue
•Hyaluronic acid
• Heparin sulphate,
• Chondroitin (IV) sulphate,.
• Dermatan
27
What do all the cells of the adluminal surface synthesize and secrete
Aminoglycans
Hematopoietic Growth Factor
Some protein ( that help promote hematopoiesis by making sure that immature hematopoietic cells are retained in the HIM until maturation )
28
Examples of the hematopoietic growth factors secreted into the HIM space
1. Granulocyte –colony stimulating factors
2. granulocyte’–macrophage: colony stimulating factor
29
Examples of proteins secreted by the adluminal cells
Fibronectin
Hemonectin
Vitronectin
Laminin
Tenascin
Endoglin
30
What are the protein secreted by the ablumimal cells
Fibronectin
Vitronectin
Hemonectin
Tenascin
Laminin
Endoglin
31
Contents of the HIM space
Reticulin fibers
Collagen fibers
Protein
Cement tissue
Erythropoietic factors
32
Examples of hematopoietic cells
Erythroid cells
Leukocytes
Throbocytes
33
What does hematopeosis consist of
Thrombopoesis
Leukopoesis
Thrombocytopoesis
34
What are the sub type of cells in the leukocytes
Monocytes
Lymphocytes
Granulocyte
35
What are the sub type of cells under granulocyte s
Neutrophils
Basophils
Eosinophils
36
Another name for thrombocytopeisis
Megakaryocytopoesis
37
Where do erythropoesis and thrombocytopoesis occur
Island of cells In close position to the adluminal surface
38
Where does granulocytopoesis occur
Inner to the location of erythropoesis and thrombopoesis
39
Where does granulocytopoesis occur
Inner to the location of erythropoesis and thrombocytopoesis
40
Where does lynphocytppoesis occur
In the very center of the HIM
41
Where does monocytopoesis occur
Close to the location for granulocytopoesis inner to thrombocytopoesis and erythrocytopoesis
42
Where are all blood cells derived from
Pluripotent stet cells
43
What are the 2 important properties of a stem cell
•Capable of cell division resulting in self renewal
•Capable of mitotic cell division accompanied with differentiation
44
What does the pluripotent stem cell become
It either divides to become more pluripotent stem cells
Or it divides to become myeloid committed stem cell and lymphoid commuted stem cell
45
What is a progenitor cell
They are commited to a hemopoetic lineage but have no microscopic or morphological identity
46
What are precursor cells
They are committed to a given hematopoietic lineage and are morphological identifiable
47
How is myeloid commited stem cell divided and why
It can divide into more myeloid committed stem cells or can discuss into BFUe, BFUmk, Highly proliferative potential CFC (HPPCFC)
This is because it’s also a stem cell
48
How do BFU ,mkBFU, and HPPCFC divide and why
They divide and mature
Because they are not stem cells
49
What time of cells are BFU and CFU
Progenitor cells
They both are morphologically unidentifiable
50
What’s the biochemical identification of the erythroid progenitor cells
Appearance of ABO blood group on the cell membrane
They also begin to express receptors for erythropoietin
51
What does E- CFU divvied to become
Mitotic division to become pro erythroblast ( first precursor cell)
52
What’s the first precursor cell
Proerythroblast
53
Describe the proerythroblast
Larder cell with large circular nucleus and thin cytoplasm
54
What’s the most distinguishing feature of the proerythroblast
Perfect circularity of nucleus
COIN NUCLEUS
55
Describe the cytoplasm of the proerythroblast
Thin rim
Has no hemoglobin hence DEEP BLUISH
56
When can the proerythroblast cytoplasm have haemoglobin
Some biochemical tests such as the FUELGEN reaction
Small quantity of HB is seen
57
What does the proerythroblast divide to become
Basophyslic erythroblast
58
What’s the most important characteristic of the basophylic erythroblast
Coin circularity of nucleus
(Just like proerythroblast)
59
Describe the cytoplasm of the basophylic erythroblast
It’s larger and not rim thin
Bluish I’m color but not DEEP bluish
(Quite different from proerythroblast)
60
What does basophilic erythroblast divide to become
Basophilic erythroblast Type 1 divides to become Basophylic erythroblast Type 2
(Little difference between them)
61
What does Basophilic erythroblast divide to become
Polychromatic erythroblast
62
Describe the nucleus and cytoplasm of the polychromatic erythroblast
Also has a coin circular nucleus but the nucleus is much smaller and the cytoplasm is much bigger
Cytoplasm is a combination of bluish and reddish
63
What is polychromasia
The mix of color in the cytoplasm of the polychromatic erythroblast (bluish and reddish)
64
What’s the difference between -cyte and -blast
-cyte : Nucleus is absent
-blast : Nucleus is present
65
What’s the change in cells and cytoplasm as we go down from proerythroblast to orthocromic erythroblast
The cytoplasm becomes bigger and
The cells becomes smaller
66
What does polychromatic erythroblast divide to become
Orthochromic erythroblast
67
What are the characteristics of the orthochromic erythroblast
Small sized cell
Cytoplasm is large and orthochromic (reddish)
Nucleus is eccentrally placed and pyknotic (shrunken)
68
Describe the nucleus of the orthochromatic erythroblast
Pyknotic (shrunken)
Almost solidified
Does not divide agains
69
What does the orthochromatic erythroblast become
Erythrocyte (annucleated)
70
How does the annucleated erythrocytes leave the HIM
By piercing through the ablumimal surface cells and the endothelial cells and joins the circulation
71
How does the erythrocytes leave the bone marrow
Through the emissary veins
72
What does the newly escaped erythrocyte contain
remants of endoplasmic reticulmm matertals and mitochondria in the cytoplasm:
Others are non-compledely removed nuclear and ribosomal materials
All these materials are removed when the erythrocyte reaches spleen.
73
How long after the erythrocyte leaves the bone marrow does the spleen remove all the remnant organelles in the erythrocyte
Approx 48 hours
74
What happens to the mature erythrocyte after the leaving the spleen
Leaves the spleen to circulate in the blood for 100-120 days
75
What is the reticulocyte and why is it called that
The erythrocytes that leave the bone marrow because it still have remnant organelles
76
When does reticulocyte stop being reticulocyte
After it leaves the spleen, it’s now a mature erythrocyte instead because it has no remnant organelle again
77
What’s the main function of the erythroid cells in the body
Reversible carriage and transfer of O2
78
Why can the RBC participate in the buffer system of the body
Because Hb has buffering capacity for human body
79
How can erythroid cells help in detoxification of the body
it complexes with poisonous gases such as carbon monoxide as Hb complexes with CO to form "carbon Mono-oxyhemoglobin”
80
What happens when the level of poisonous gases in the blood becomes too much
reversible oxygen carriage becomes problematic
81
How many mitotic divisions between proerythroblast and othrochromatic erythroblasts
4
82
Why can’t the orthochromatic erythroblast divide
Because the nucleus has become pyknotic and can only be removed
83
How many erythrocytes are yielded from one proerythroblast
16
84
What happens when there is insufficient DNA material for replication
Leads to
-Fail in mitosis
-Lesser number of mitotic stages
-Reduced no orthochromatic erythroblast and erythrocytes
-Each daughter erythrocytes will be bigger in size
85
What’s the disease called when there is insufficient material for DNA replication
MACROCYTIC/ MEGALOBLASTIC ANEMIA
Reduced RBC in circulation but cell size is bigger
86
What is megaloblastic anemia
Reduced RBC in circulation but fell size is big
Due to insufficient material for DNA replication
87
What is cytoplasmic nuclear synchrony
The type of maturation where the cytoplasm becomes bigger but the nucleus becomes smaller
(Occurs in normal maturation sequence of the erythroid)
88
What is Cytoplasmic Nuclear Asynchrony
A situation where the nucleus is unable to replicate/mature (divide into smaller divisions) but the cytoplasm is still maturing (getting hemoglobinised and bigger)
89
What is an erythroid blast with features of cytoplasmic nuclear asynchrony called
Megalobalst
90
What happens when the material for nuclear replication is available BUT not material for cytoplasm maturation (lacking in Hb synthesis)
Microcytic anemia
91
What happens in microcytic anemia
Due to lack of maturation of cytoplasm but continual maturation of nucleus
-The No of mitotic division between pro and orthochromatic erythroblast increases
-Instead of having 16 cells , they MIGHT end up being 32 cell
-They are smaller in size
-And are called microcytes
92
The microcytic and megaloblast Anemia are diseases of what and what
Microcytic anemia : Disease of the synthesis of haemoglobin
MEGALOBLASTIC anemia: Disease of the replication nucleus
93
What’s the haemoglobin conc of the cytoplasm of megaloblasts and microcytes
Megaloblast : haemoglobin rich cytoplasm
Microcytes : haemoglobin deficient cytoplasm
94
What are the requirements for the calculation of red cell indices
Red cell count
Packed cell volume
Hb concentration
95
What is red cell count
no of red cells present in 1L of blood
Approx 5 trillion cells
96
What’s packed cell volume
total voulme of red cells in 1L of whole blood.
0.4L of red cells in 1L of blood
97
What is Hb concentration
amount of Hb present ni 1L of whole blood
150g of Hb in 1 L of blood; 150g/L or 15g/dL
98
What are the red cell indices
MCV mean cell volume
MCH mean cell Hb
MCHC mean cell Hb concentration
99
How do you calculate MCV
PCV/red cell count
O.4/5 trillion
=80fentoliter
100
How do you calculate mean cell Hb
Hb conc/red cell count
150/5 trillion
30picogram
101
How do you calculate MCHC
Hb conc/pcv
150/0.4
375g/L or 37.5g/dL
102
Describe the MCV, MCH, MCHC in megaloblasts
MCV: High
MCH : High
MCHC : Normal/High
103
Describe Describe the MCV, MCH, MCHC in microcytes
MCV: always low
MCH: always low
MCHC: always low
104
What is megakaryocytopoesis
Formation of platelets
105
What does the myeloid committed stem cell divide to in megalaryopoesis
mkBFU
106
What does mk BFU divide to become
mkCFU
107
What are the platelets progenitor cells
mkBFU and mkCFU
108
What do mkCFU divide to become
Megalaryoblast (first precursor cells)
109
What’s the first precursor cell on megakaryopoesis
Megakasryoblast
110
Describe the megakaroblasts
usualy a smal sized cell, just slightly bigger than the lymphocytes and sometimes difficult to differentiate
111
What does megakaryoblast undergo
Undergoes endonuclear reduplication to become 2-N stage megakaryoblast
112
What does 2-N stage megakaryoblast become
Divides to become 4-N stage megakaryoblast
113
What’s the progression of the division of megakaryoblast
Megakaryoblast ➡️ 2-N stage megakaryoblast ➡️ 4-N stage megakaryoblast ➡️ 8-N stage ➡️ 16-N stage ➡️ 32- N stage ➡️ 64- N stage ➡️ 128- N stage megakaryoblast
114
What is endonuclear reduplication
A mitotic division where the nucleus is duplicated without resulting
in cell division is called endonuclear REDUPLICATION.
115
What are platelets formed from
They are formed as fragments of the cytoplasm of mature megakaryocytes
116
What are the functions of platelets
1. helps to seal injured/damaged blod vesels.
2. have capacity to replace endothelial cells when there's
denudation of endothelial cells
117
What is platelet adhesion
When platelets lie over the sub endothelial structures,
118
What is platelet aggregation
When platelets lie over another platelet,
119
What mediates platelet adhesion
GP Ib receptor that attaches to VW factor (an adhesive protein) which attaches to subendothelial surface
120
What must be present for platelet adhesion
Platelet
VW factor
GP Ib receptors
121
What’s the deficiency of GP Ib receptor
Benard-Soulier Syndrome
122
What does platelet need for aggregation
GP IIa/IIIb receptor (that binds to fibrinogen)
123
What must be present for platelet aggregation
Platelets
GP IIa/IIIb receptor
Fibrinogen
124
What’s the deficiency of GP IIa/IIIb receptor
Glanzmann’s disease
125
What does myeloid committed stem cell divide into
Ery- BFU
Mk- BFU
HPPCFC
126
Hat does HPPCFC stand for
Highly proliferative potential colony forming cell
127
What does HPPCHC divide into
HPPCHC type 1 divides into HPPCHC type 2
128
What does HPP-CFC- type 2 divide into
CFC-Eos
CFC-Bas
GM-CFC
129
What does GM-CFC (granulocyte macrophages CFC) divide into
G-CFC :granulocytes CFC
M-CFC :macrophages CFC
130
What does CFC-Eos, CFC-Bas and G-CFC all join to become
Myelobalst
131
Is the myeloblast coming from CFC-Eos, CFC-Bas and G-CFC differentiatable
No, they’re not differentiatable
132
What are progenitor cells for the granulocyte
HPPCFC
CFC-Eos
CFC-Bas
GM-CFC
G-CFC
133
What’s the first precursor cells for granulocyte
Myeloblast
134
What does myeloblast divide to become
Promyelocyte
135
Describe the myelocyte (nucleus and cytoplasm)
Mononuclear cell with an ovoid/roundish nucleus
The cytoplasm lack granule except 1 or 2 primary granules
136
Describe the promyelocytes
It’s a large cell with a large cytoplasm with a great quantity of primary granules
137
Describe the primary granules of promyelocytes
Basophilic,thick and prominent in the cytoplasmic
138
Is the promyelocytes of Eosinophils, Basophils and granulocyte differntiatable?
No
139
What does promyelocyte divide into
Myelocyte
140
When does secondary granule start develop (what developmental stage)
Myelocyte
141
What stage are secondary granules developed
Myelocytes
142
What differntiates Esonophil, Basophils and Neutrophils
Secondary granules
143
At what stage can Eosinophils, Basophils and Neutrophils differentiatable
At the Myelocyte (due to secondary granules)
144
What do the myelocytes (whether Basophilic, eosinophilic or neutrophilic) divide to
Basophilic metamyelocyte
Eosinophilic metamyelocyte
Neutrophilic metamyelocyte
145
What do metamyelocytes become
The become Eosinophilic band/Basophilic band/ Neutrophilic band which further mature to become (SEGMENTED GRANULOCYTES) - segmented eosinophils, segmented basophils, segmented neutrophils
146
What’s the nucleaic feature of the myelobast, promyelocytes and myelocyte
Mononuclear with a oval/roundish nucleus
147
What happens to the roundish nucleus at the metamayelocyte stage
There is an indentation to become BEAN SHAPED
148
What happens to the indentation of the nucleus of the metamyelocyte as it matures further
The indentation deepens to become band cells
149
What are the Basophils also referred to as
The alarm cells of the body
150
Why are the basophils referred to as the alarm cells of the body
They mediate inflammation by production histamine and other inflammatory mediators
151
What’s the function of Eosinophilic cells
Fight against tissue parasitic infection
152
How do Eosinophils kill tissue parasites
The Charcot-Layden granules (that they possess) are able to dissolve the outside coating of nearly all tissue parasites , immobilize and kill them
153
What’s the function of neutrophils
They mediate Opsonization resulting in ingestion or phagocytosis of acute bacterial agents which are then killed by the granular contents of the basophils
154
What is monocytes derived from
Thé monocyte’s also derivative of HPP- CFC. HPP-CFC type:1: gives rise ot HPP- CFC type 2; This then gives rise to GM-CFC,which then gives rise to: CFC-M;, which then gives nise ot monoblast: Monoblast —Promonocyte: —Monocyte:
155
How are monocytes circulated in the blood and stored in organs
Circulated in the blood as monocytes but stored in tissues as different macrophages
156
What are the different types of macrophages in the body
Liver - kupfer cells
Bone marrow - Histiorytes:
spleen - follicular dendritic cell
skin - langerhan cells
kidney - Mesangial cela
lymphatics - veil cells:
Lungs - Alveolar macrophages
157
What are all the macrophages collectively referred to as
Monocyte macrophages mononuvlear system cells
Reticuloendotgelial nuclear cells
158
What are the major function of the MMMSC
•They are the systems that help to contain all chronic bacterial infections particularly TB
• they are responsible for immune responses against several fungal infections
• They phagocyte particulate agents that infiltrate the lung like dust
159
What happens to the MMMSC with age
They weaken with age
160
What are the 2 division of the MMMSC
***Group 1: the cells capable of continued mitosis***, hence, enrich the tissue of where they are with monocytes dependent immune function
***Group 2: cells which are incapable of continued mitosis***, once formed the continue to function to archive dust, bacterial or fungal infection, and a time comes when they are no longer cap of archiving insults of microorganism, which is why with age immune functions decline and older people have a higher rush of bacterial and fungal Infection
161
What does the lymphoid committed stem cell divide into
Pre B cells
Pre T cells
162
How are lymphoid committed stem cells Identifiable
By a cluster of differentiation antigen called ***CD 10***
163
What is CD10
They are receptors often found on cell membranes, and they are used to identify the cell. However, most of these receptors have their own function, but their main function is for identification of cells.
Also called common ALL antigen
164
What is common ALL antigen
CD10
Common acute lymphoblastic leukemia antigen
165
Where are pre B cells found
At the center of the HIM
Often Identified by demonstration of immunoglobulin gene rearrangement
166
What is Germ Line
The genes in all cells as inherited at fertilization
167
What happens to germ line inheritance
Rearranged in 2 cell types
B lymphocytes
T lymphocytes
168
Why does gene rearrangement occur in B lymphocytes
Gives the body the capacity to form antibody to any type of antigen found in nature
169
To produce an antibody to a specific antigen, what needs to happen
There must be a B cell circulating in the blood already with the immunoglobulin to that particular antigen
170
Why is every B cell in the body different
They all contain different surface membrane immunoglobulin
171
How does the body have the ability to form different B cells immunoglobulin
Gene rearrangement phenomenon
172
How are different B cell immunoglobulins formed
If a B- cell is going to be formed, it’s has germ line Ig gene. That particular B cell will rearrange the germ line Ig gene to produce a specific antibody for an antigen in nature. Another B cell with rearrange it’s own germ line Ig gene to form it’s own specific antibody for an antigen in nature (different for the other B cell antibody)
173
How is an Ig formed
By forming a light chain and a heavy chain of Ig
174
What are the regions on the heavy chain
Variable region
Diversity region
Joining region
constant region
175
What are the Ig heavy chain regions
Variable region
Diversity region
Joining region
Constant region
176
What are the Ig light chain regions
Variable region
Constant region
177
What is The germ line inheritance of Ig gene for heavy chain
Everyone has 39 to 49 variable regions gene, 10 variable region genes, 6 joining region genes, and 9 constant region genes
178
What are the types of the light chain Ig gene
Lamda and kappa chain
And they cannot both exist on on Ig
179
How many variable region chain and constant region chain do the lamda and kappa have
40 variable region chain
2-3 constant region chain
180
When genes are rearranged to form antibodies, where are they secreted
Cell membrane and not plasma thats why they are called surface membrane Ig
181
How is an antibody formed from the heavy chain
One of all the region genes in the Ig heavy chain are selected, while the rest are deleted
182
When In the Pre B cell stage, if checked for the germ line inheritance, what is seen
The germ line is no longer seen at This stage because it has been rearranged
183
Where is the immunoglobulin found in the Pre B cell and why
Found in the cytoplasm (no longer membrane) because by this time , tot has started producing the Ig it rearranged its gene for, hence ***pre B cell has cytoplasmic Ig***
184
What does pre B cell mature to become
B-celli n transibon
185
What 2 things are used to identify pre B cell
•Molecular technique to demonstrate Ig gene rearrangement
• Staining techniques ( it lol be +be for cytoplasmic Ig)
186
What is peculiar about B cell in transition
It’ll have booth cytoplasmic Iv and surface membrane Ig
187
What does B cell in transition divide to become
Circulating / Virgin B cell
188
What type of Ig is present in circilulating B cell
Only surface membrane Ig
189
What type of Ig is pre B cell +ve for
Cytoplasmic Ig
190
What type of Ig is B cell in transition +ve for
Both cytoplasmic and surface membrane Ig
191
What type of a Ig is virgin B cell +be for
Surface membrane Ig
192
What B cell receptors are present in all B cells for B cell in transition to the last B cell in development
CD 19
CD 20
CD 21
CD 22
and when activated CD23
193
What happens to a Virgin B cells
It remains the way it is forever ( no further development) unless its surface membrane Ig comes in contact with a corresponding antigen in nature, then it undergoes further development
194
What does further development of the virgin B cell depend on
Antigenic stimulation
195
Where does further development of the virgin B cell occur
I’m the lymph nodes and not peripheral circulation
196
What does the antigenically stimulated B cell home
The Lymph nodes follicles (in the cortex)
197
What area of the lymph nodes surround the lymph node follicles
Paracortex
198
What area of the lymph nodes paracortex merged with the lymph nodes follicles
The marginal zone of the lymph node
199
What area of the lymph node follicle is inner to the marginal zone
Mantle zone
200
What cells are present at the very center of the lymph nodes follicle
Follicular center cells
201
What exact part of the lymph node follicle is the antigenically stimulated B cells located
In the follicular center
202
What happens if the virgin B cells stops at the marginal or mantle zone rather than the follicular center
It will not be able to continue its development as a B cell
203
What does the virgin B cell mature to become
The small cleaved B cell
204
What does the small cleaved B cell mature to become
Large cleaved B cell
205
What does the large cleaved B cell mature to become
Small non cleaved B cell
206
What does the small non cleaved B cell mature to become
Large non cleaved B cell
207
What does the large non cleaved B cell divide to become
B immunoblast
208
What does the B immunolblas do after it’s formation
It leaves the follicular center of the lymph nodes and travel to the bone marrow
209
What does the b immuniblast mature to become in the bone marrow
B plasmacytoid cell
210
What does b plamsacytoid cell divide to become
Plasma cells
211
Where are plasma cells found
Bone martow
212
What development of B cells occur in the follicular center
From virgin B cell to B immunoblast
213
How long does it take for a virgin B cell to become a plasma cell that’ releases antibodies
14 days
214
What happens to the surface membrane Ig of the B cell when it becomes a plasma cell
It begins to form that same Ig l, but not to incorporate it to the membrane but to release it into the plasma
215
What is the period of time when an antigen is present in the body but the corresponding antibody is yet to be produced called
Serologic latency period
216
What happens to some of the B immunoblast that don’t become a plasmacytoid cell
Some of the B immunoblast reverse in morphological appearance to look like virgin B cells (memory cells)
217
What are memory B cells
Virgin B cells that have previously undergone maturation to B immunoblast stage of development
218
What is the purpose of the memory phenomenon
It occurs to shorten immunological reactions so that if that same antigen comes in again, instead of going through all the stages of development again, the virgin B cell will just become a B immunoblast, ( which then becomes a plasmacytoid cell and a plasma cell right away)
219
What is the phenomenon of vaccine
It uses the memory phenomenon
So it introduces A (weaker version) of an antigen, so that the B cells can undergo gene arrangement to produce an antigen for that specific antigen , so that when the actual antigen attacks the body, there would be memory cells that will hasten the immunologic reaction and attack the antibody
Also there’s a larger number of plasma cells produced and a larger number of antibodies ***Called vaccine boosting ***
220
How many days does it take for memory B cells to produce plasma cells
3-4 days
221
How many plasma cells can be gotten from one virgin B cell
128 plasma cells (they all produce the same Ig)
222
What are the functions of the B cell
•Mediate humoral immunity for the organism that its directed against (viral and bacterial organisms)
223
What is Ig referred to as opsonin
When a bacteria enters the body, the corresponding antibody attaches to the antigen on the membrane of the bacteria . Such bacteria that has Ig antigenically attached to its surface membrane is said to be opsonized
The opsonized bacteria is now susceptible to phagocytes by ( neutrophils and monocytes)because they have receptors for the Fraction crystallization (FC) fragment of Ig
224
How do neutrophil and sometimes monocyte help with the phagocytes of opsonized bacteria
They bind with the altered FC fragment on the Ig (that has opsonized the bacteria) ***binding of Ig to a bacteria alters it’s FC fragment, it’s the altered FC fragments that neutrophils and monocytes recognize ***
Hence phagocytes cannot occur except opsonization has occurred
225
What cluster of differentiation antigen makes Pre T cells identifiable
CD 2 and CD 3
226
How does the T cell travel
It leaves the HIM space and travels to the thymus into the thymus lobule
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What is the pre cortical T cell
The pre T Cell that has gotten to the thymus lobule but is yet to enter the cortex of the the thymus lobule
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What CD is present in the pre cortical T cell
CD1, CD2, CD3
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The happens to the pre cortical T cell
The enter the cortex of the thymic lobule to become the cortical T cell
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What CD is pre cortical T cell specific
CD 1
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What happens to the T cell when it becomes cortical
The cortical T cell loses CD1 but gains CD 4 and CD 8
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What CD antigens are +be in the cortical T cell
CD 2 , CD3, CD 4, CD8
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What does the cortical T cell become
It moves from the thymic cortex to the thymic medulla to become the medullary T cell
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What happens to the T cell when it becomes medullary
It loses ***either*** CD 4 ***or*** CD8
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What CD is +ve in medullary T cell
Either CD2, CD3 and CD4 (but CD8 -ve)
Or CD2, CD3 , and CD8 (but CD 4 -ve)
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What % of the T cells in the body are either CD 4 or CD8 +ve
95%
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After the medullary T cells, what are the other types of T cells
T delayed hypersensitivity cells
T suppressor cells
T natural killer cells
(All make 5%)
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How does the medullary T cell Travel
It leaves the the medulla of the thymic lobule into the circulation to become circulating T cell/virgin T cell
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What kind of immunity does T cell mediate and B cell mediate
T cell: cellular immunity
B cell: humoral immunity
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How does T cell carry out cellular immunity
T cells identify a pathological cell in the body (viral infected cell/ undergoing mitotic change) and the delivers a cytotoxic kill using its cytoplasmic content
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How does T cell escape/survive the cytotoxic kill it delivers to pathologic cells
It has calci reticulin molecules within it that neutralizes it’s cytolytic proteins
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Examples of the calci reticulin molecules that protect T cells from its cytolytic proteins
Perforin
Caspases
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How does the T cell identify the cells to be eliminated
It’s identifies the neo antigen expressed on the membrane of the cell. It used T cell receptors (TcR) to identify the neoantigen
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How is TcR capable of identifying different neoantigen
Just like we have B cell germ line, there’s also T cell germ line that’s also rearranged in many ways so that there’s a TcR for as many neoantigens in the body
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What can cause further development of a circulating T cell
The circulating T cell has to come in contact with its corresponding cellular antigen in nature
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What happens to the circulating T cell when it is antigenically stimulated
Just like the B cells , it travels to the lymph node (but for T cell, it stays in the ***lymph node paracortex***)
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What happens to the circulating T cell if it’s antigenically stimulated
Just like B cells, it also travels to the lymph node for further maturation (but for T cells , it stays in the ***lymph node paracortex***)
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What’s the B cell home (in the lymph node)
Lymph node follicular center
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What’s the T cell home ( in the lymph nodes)
Lymph nodes paracortex
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In the lymphoid paracortex, what does the virgin T cell become
It’s become small non cleaved T cell
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What does small non cleaved T cell become
Large non cleaved T cell
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What B cells have no T cell counterparts
The small and large cleaved B cells
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What does large non ckeaved T cell become
T immunoblast
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What does the T immunoblast mature to become
The T immunoblast does not mature any further, it only accumulates effector molecules it uses to carry out its cytolytic functions
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What happens to some of the T immunoblast
Just like some B immunoblast, some. T immunoblast can also undergo morphological reversal to look like the circulating T cell
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What are memory T cells
The are virgin T cells which have previously undergone maturation to the stage of T immunoblast but were morphologically reversed
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What are the 2 major broad types of T cells
CD 4 + cell
CD 8 + cell
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What’s the function of the T delayed hypersensitivity cell
give helper signals ot macrophages,to support or enhance the macrophage immune functions against, chronic bacterial, illness and against fungal illnesses
They supply ***gamma-interferons*** to aid. monoryte-macrophage-functions. against chronic bacterial and fungal infections
(T cells surround granulomatous tissue against TB in caseous necrosis)
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What’s the function of the T supressot cells
limit immune hyper activity
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What happens to people with deficiency in T supressot cell
They have immune hyper activity
(Auto immunity disease) eg systemic lupus erythromatotus
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What’s the function of the T natural killer cells
***Gods' given immunity against development of cancer***
Capable of identifying neoantigen on cells undergoing mitotic changes and delivers cytolytic kill to them
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Gat are the CD 8+ cells functions
Cells given by God as a major defense against viral infections
All cells infected by viruses are often identified by cytotoxic T cells and it delivers cytotoxic kill
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What’s the function of CD 4 + cells
These are the T helper cells
The help other immune cells to function properly
Render help to B cells, macrophages, CTL, T suppressor cells, T delayed hypersensitivity cell, T NK cell
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What happens in the absence of T helper cells (CD4+)
No other immune cells function well
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What are the types of the T helper cells
TH 1
TH 2
TH 17. (Helps to produce a cytokine: interleukin 17)
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What is TH 2 cell also referred to as
T regulatory cell
It helps other T cells carry out their functions
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What the function of the TH 1
It’s the effector cell
It’s able to cytolize other cells
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What kind of cells can HIV infect
CD4+ cells
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How does HIV infect CD4+ cells
It used its membrane GP 120 to interact with the CD4 molecule and becomes anchored to its membrane . The virus also fuses its membrane with the human cell membrane and becomes internalized into the cytoplasm of CD4+ cells
Attacking CD4+ cells restricts the function of other T cells and the immune is compromised
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When a person is HIV infected, what other diseases are they at risk for
Chronic fungal infection, acute bacterial infection, cancer as NK cells no longer function
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What are the 4 goals of Anti retroviral therapy
Virologic goal
Immunologic goal
Clinical goal
Epidemiological goal
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Explain the virologic goal of antiretroviral therapy
The virus become undetectable once the drug is taken
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What is the immunologic goal of antiretroviral therapy
Because the virus effect is no longer detected, the bone marrow can now produce new CD4+ cells
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What’s the clinical goal of the antiretroviral therapy
The cessation of opportunistic illnesses (bacteria , fungal infections, cancer) when immunity is reconstituted
275
What is the epidemiological goal of antiretroviral therapy
Once a patient achieves the virological goal, the person becomes uninfectious
For every patient on effective antiretroviral therapy , 5-10 new infections have been prevented
That’s the epidemiological goal
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What’s another name for CD8+ cell
Cytotoxic T cell
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What’s another name for CD4+ cells
T helper cells
