Blood Cell Dynamics Flashcards
mag aral (176 cards)
1
Q
How is blood cell replacement achieved in hematopoiesis?
A
Blood cell replacement in hematopoiesis is achieved through the activity of hematopoietic stem cells (HSCs), which have the ability to self-renew and differentiate into various blood cell types.
2
Q
It was mentioned that HSCs are located in specific areas, so where does hematopoiesis occur during prenatal life?
A
blood islands in the yolk sac
mesenchyme
blood vessels
liver
spleen
thymus
lymph nodes
bone marrow
3
Q
how does the distribution of red bone marrow change with age?
A
In postnatal life, hematopoiesis occurs in red bone marrow, which is initially widespread but gradually replaced by yellow marrow with age.
4
Q
In later life, where does red bone marrow remain active?
A
in the sternebrae, ribs, vertebrae, cranial bones, and other flat or irregular bones.
5
Q
what are the 3 theories on the nature and fate of the stem cells
A
Monophyletic theory
Diphyletic theory
Polyphyletic theory
6
Q
what is the most accepted theory about the nature and fate of the stem cells?
A
monophyletic theory
7
Q
explain the most accepted theory.
A
states that all blood cells arise from a single stem cell
which is the pluripotential hemopoietic cell
8
Q
difference of the diphyletic and polyphyletic theory.
A
The Diphyletic Theory suggests that blood cells come from two distinct stem cell lines: one for lymphocytes and another for myeloid cells (RBCs, granulocytes, monocytes, platelets).
The Polyphyletic Theory proposes that each blood cell type originates from its own specific stem cell, meaning multiple independent stem cell lines exist.
9
Q
How do the size and nucleus of blood cells change as they mature?
A
Early blood cells are large with a large nucleus, but as they mature, they become smaller, and the nucleus decreases in size.
10
Q
How does the staining of the nucleus change during cell maturation?
A
The nucleus of young cells is light-staining and acidophilic, but with maturation, it becomes darker and basophilic.
11
Q
How does the cytoplasm change as blood cells develop?
A
The cytoplasm of young cells is basophilic and gradually becomes acidophilic as they mature.
12
Q
What happens to the shape of the nucleus in granulocytes as they develop?
A
The nuclei of stem cells start as round and light-staining, but with maturation, they become indented, lobed, or segmented, with darker-staining chromatin.
13
Q
What type of granules are found in early granulocytic cells, and how do they change with maturation?
A
Early cells contain azurophilic or non-specific (primary) granules, which are later replaced by specific granules in mature granulocytes.
14
Q
What happens to nucleoli during blood cell maturation?
A
Early cells have one or more nucleoli, but these become less apparent and eventually disappear as the cells mature.
15
Q
How does mitotic activity change during blood cell development?
A
Mitotic activity is high in more primitive cells, but it decreases as cells mature.
16
Q
In which species is the nucleus of mature erythrocytes extruded?
A
mammals
17
Q
What happens to the chromatin structure as cells mature?
A
The chromatin in early cells has a fine reticulated distribution, but with maturation, it becomes more clumped and stains more darkly.
18
Q
It is hypercellular and highly
vascularized form of connective tissue, which is
associated intimately with bone as an organ.
A
Bone marrow
19
Q
Where is bone marrow located?
A
marrow (medullary) cavity of bones
20
Q
What happens to bone marrow during development and growth?
A
During development and growth, all bone marrow is red bone marrow before some of it is later replaced by yellow bone marrow.
21
Q
In adults, where is red bone marrow primarily found?
A
In adults, red bone marrow is confined to the sternebrae, vertebrae, ilia, ribs, cranial bones, and ends of long bones.
22
Q
What gives red bone marrow its characteristic red color?
A
The red color comes from the accumulation of erythrocytes, erythrocytic precursors, and their pigments.
23
Q
What is another name for red bone marrow, and what is its primary function?
A
Red bone marrow is also called myeloid tissue, and its primary function is blood cell production (hematopoiesis).
24
Q
Which blood cells are produced in red bone marrow?
A
Erythrocytes, granulocytes, and platelets are produced in red bone marrow, while agranulocytes also develop here and in lymphatic organs.
25
What are the three major compartments of bone marrow?
Stem Cell Pool
Differential Proliferating Pool
Maturation Pool
26
What structures are found within the red bone marrow?
Red bone marrow consists of arterial and venous channels, sinuses, a reticular fiber network, free cells of blood cell lineages, macrophages, and some adipose tissue.
27
bone marrow compartments where myeloblasts, progranulocytes, etc, are seen
Differential Proliferating Pool
28
what cells can you find in the maturation pool?
metamyelocytes, band cells and mature segmented
granulocytes
29
What is the primary component of yellow bone marrow?
adipose tissue
30
What happens to the hemopoietic compartment when yellow bone marrow develops?
The adipose tissue in yellow bone marrow replaces most of the blood cell-producing elements of the hemopoietic compartment.
31
Under what conditions can yellow bone marrow become active again?
Under stressful conditions, such as disease, yellow bone marrow can revert to active hemopoietic tissue.
32
Where do all circulating blood cells originate from?
pluripotential hemopoietic stem cells
33
What is the role of pluripotential hemopoietic stem cells in blood cell formation?
undergo successive divisions to form different blood cells throughout an individual’s life.
34
Do all pluripotential hemopoietic stem cells actively produce blood cells?
No, many PHSCs in the bone marrow remain as reserved stem cells for future needs.
35
What is the first offspring of PHSCs called?
committed stem cells
36
How do committed stem cells differ from PHSCs?
Unlike PHSCs, committed stem cells are assigned to produce a specific cell line.
37
committed or assigned to produce a specific cell
line.
Committed stem cells
38
Can yellow bone marrow produce blood cells under normal conditions?
No, under normal conditions, yellow bone marrow does not actively produce blood cells, but it can convert back to red bone marrow in times of need.
39
What is the colony-forming unit responsible for erythrocyte production?
CFU-E (Colony-Forming Unit-Erythrocyte)
40
Which progenitor cell gives rise to both granulocytes and monocytes?
CFU-GM (Colony-Forming Unit-Granulocyte-Monocyte)
41
What is the progenitor cell for platelet formation?
CFU-Megakaryocyte (CFU-M)
42
From which stem cell type do B and T lymphocytes originate?
B and T lymphocytes originate from Colony-Forming Unit-Lymphocyte (CFU-LH) or Lymphoid Stem Cell (LSC).
43
How does the differentiation pathway of lymphocytes differ from that of erythrocytes, granulocytes, and platelets?
Lymphocytes originate from a less differentiated cell (CFU-LH/LSC), while erythrocytes, granulocytes, and platelets arise from more committed progenitor cells (CFU-E, CFU-GM, CFU-M).
44
What is erythropoiesis?
Erythropoiesis is the production of erythrocytes (red blood cells).
45
What is the first cell in the erythrocytic series?
Rubriblast (Proerythroblast or Pronormoblast)
46
Arrange the following stages of erythropoiesis in the correct sequence, from the earliest to the most mature form:
Reticulocyte
Rubriblast
Normochromatic Rubricyte
Metarubricyte
Basophilic Rubricyte
Prorubricyte
Polychromatic Rubricyte
Erythrocyte
Rubriblast → Prorubricyte → Basophilic Rubricyte → Polychromatic Rubricyte → Normochromatic Rubricyte → Metarubricyte → Reticulocyte → Erythrocyte)
47
the nucleus is spherical, light purple with netlike
chromatin pattern.
The cytoplasm has a mottled appearance; it is blue
green while the perinuclear region is light blue;
one to three prominent nucleoli are seen.
This is the first cell in the erythrocytic series.
Rubriblast (proerythroblast or pronormoblast)
48
smaller than the previous form and appears quite similar to the rubriblast except that the nuclear
chromatin is starting to condense and has no nucleoli
or nuclear rings.
Mitotic activity is high.
Prorubricyte (basophilic erythroblast, basophilic
normoblast)
49
a small cell with a small round and dense nucleus.
The nuclear chromatin is clumped.
Nucleoli are not apparent.
The cytoplasm has a deep greenish blue or dark navy blue color due to the presence of RNA.
Basophilic Rubricyte (basophilic normoblast)
50
the nucleus becomes very condensed with coarse,
clumped chromatin.
The cytoplasm has a muddy bluish red color due to the
increase in hemoglobin.
The mixture of a basophilic cytoplasm due to RNA and
the orange-red hemoglobin is responsible for the
polychromasia.
Polychromatic rubricyte (normoblast)
51
has a dense nucleus and has more hemoglobin than
polychromatic rubricyte
Normochromatic
rubricyte
Normoblast)
52
nucleus is absent and the cytoplasm has a muddy blue
color because of the residual RNA.
Reticulocyte (diffusely basophilic cell)
53
nucleus may be partially extruded or fragmented and
the cytoplasm may be polychromatic to
normochromatic depending on the hemoglobin
present in the cell after the nucleus has been extruded.
Metarubricyte (late normoblast)
54
What is the characteristic appearance of the nucleus in a Rubriblast?
The nucleus is spherical, light purple, with a netlike chromatin pattern and one to three nucleoli.
55
How does the cytoplasm of a Prorubricyte differ from that of a Rubriblast?
The Prorubricyte’s cytoplasm is darker (deep blue-green) due to more RNA, and the nucleoli disappear.
56
How does nuclear chromatin change as erythropoiesis progresses?
The chromatin condenses, becoming clumped and darker until the nucleus is finally extruded in later stages.
57
Why is the cytoplasm of the Basophilic Rubricyte deep greenish-blue or dark navy blue?
Because of high RNA content, which stains basophilic (blue).
58
What causes the polychromatic appearance of the Polychromatic Rubricyte?
A mixture of RNA (blue) and hemoglobin (red-orange) gives a muddy bluish-red color.
59
How does the Metarubricyte differ morphologically from the Normochromatic Rubricyte?
The nucleus of the Metarubricyte is partially extruded or fragmented, while the cytoplasm continues to gain hemoglobin.
60
What is the last stage of erythropoiesis where a nucleus is present?
The Metarubricyte (Late Normoblast).
61
What is a key distinguishing feature of a Reticulocyte?
It has no nucleus, and its cytoplasm has a muddy blue color due to residual RNA.
62
How does a mature Erythrocyte differ from a Reticulocyte in terms of morphology?
A mature erythrocyte is biconcave, lacks RNA, and has a uniform pinkish cytoplasm due to full hemoglobin content.
63
What is the trend in cell size as erythropoiesis progresses?
The cell size decreases as the erythrocytes mature, with early cells being larger and later stages becoming smaller and more compact.
64
This is the production of granulocytes.
Granulocytopoiesis
65
large with basophilic (light blue-green) cytoplasm
which is usually darker in the periphery than in the
perinuclear region.
The nucleus is large, finely reticular and purple
staining, appears velvety.
Two or more pale blue nucleoli may be observed.
(Granulocytopoiesis series )
Myeloblast
66
is a large cell which may even be larger than the
myeloblast.
The nucleus is round with coarsely distributed
chromatin.
Two or three nucleoli may be present but are not
readily observed.
Granules are present in the pale purple, foamy
cytoplasm and vary from acidophilic to basophilic.
There is a gradual decrease in nonspecific granules
and a gradual increase in specific granules.
Mitotic activity is high.
Progranulocyte
67
is the first recognizable stage of the specific
granulocytes that will develop.
Contains some specific granules and few remaining
azurophilic granules distributed throughout the
pale blue staining cytoplasm.
The granules stain differently because of the
presence of both mature and immature granules.
The nucleus is spherical with slight indentation and
clumped chromatin.
Promyelocyte
68
In __ promyelocytes, the granules are brown, purple or dark blue; in basophilic promyelocyte, they are dark purple, pink or brown; and in neutrophilic promyelocytes, they are pale pink and blue.
eosinophilic
69
the nucleus is smaller and the chromatin shows
clumping than the previous stages.
The nucleus is also more oval than round and a slight indentation may be apparent.
The cytoplasm is pale blue.
Mitosis is high.
Myelocyte
70
cells are smaller, their specific granules mature and the nucleus is characterized by bean shaped or horse-shoe shaped appearance.
The cytoplasm is slightly acidophilic and filled with
specific granules.
Metamyelocyte
71
A neutrophilic metamyelocyte is also called as
____.
juvenile
72
characterized by a horseshoeshaped nucleus in Granulocytopoiesis
Band cell
73
characterized by lobed nucleus.
Specific granules are numerous.
Mature granulocyte
74
What is the characteristic appearance of the cytoplasm in a Myeloblast?
The cytoplasm is basophilic (light blue-green), darker at the periphery than the perinuclear region.
75
How does the nucleus of a Progranulocyte differ from that of a Myeloblast?
The Progranulocyte nucleus is round with coarsely distributed chromatin, whereas the Myeloblast nucleus is finely reticular and velvety.
76
At which stage do specific granules first appear?
Promyelocyte
77
How can you distinguish a Myelocyte from a Promyelocyte?
The Myelocyte nucleus is smaller, more oval, and more clumped, while the Promyelocyte nucleus is round and slightly indented.
78
What is the distinguishing feature of a Metamyelocyte’s nucleus?
The nucleus is bean-shaped or horseshoe-shaped.
79
Which stage of granulocytopoiesis is also called a “juvenile” in neutrophils?
Neutrophilic Metamyelocyte
80
What is the key characteristic of a Band Cell’s nucleus?
The nucleus is horseshoe-shaped, without complete segmentation.
81
How do the granules differ among the three types of Promyelocytes?
Eosinophilic Promyelocyte – granules are brown, purple, or dark blue.
Basophilic Promyelocyte – granules are dark purple, pink, or brown.
Neutrophilic Promyelocyte – granules are pale pink and blue.
82
What nuclear characteristic defines a Mature Granulocyte?
lobed nucleus
83
How does the cytoplasm of an immature monocyte appear?
It is abundant, blue-stained, and contains few azurophilic granules.
84
How do the specific granules change as the granulocyte matures?
Non-specific granules decrease, while specific granules increase and become more prominent.
85
production of lymphocytes and monocytes,
macrophages and plasma cells.
Agranulocytopoiesis
86
where does Agranulocytopoiesis occur?
lymphoid organs as well as in bone
marrow
87
What happens to the nucleus of a monocyte as it matures?
It becomes indented on one side, but the nucleoli remain.
88
How can you distinguish a Lymphoblast from a Prolymphocyte?
A Lymphoblast has a large, round vesicular nucleus with prominent nucleoli, while a Prolymphocyte has a nucleus with more coarsely clumped heterochromatin.
89
Which lymphocytic stage has the most basophilic cytoplasm?
the Lymphoblast stage has the most basophilic cytoplasm.
90
hat happens to the size of monocytes as they mature?
They become smaller with maturation.
90
How do promonocytes compare to granulocytic precursors?
Promonocytes are difficult to distinguish from granulocytic precursors because they share a large size and similar immature features.
91
How does the staining of a monocyte’s cytoplasm change as it matures?
It changes from blue-stained to blue-gray.
92
What is the largest cell in the lymphocytic series?
Lymphoblast
93
How does the chromatin of a Prolymphocyte differ from that of a Lymphoblast?
The Prolymphocyte has more coarsely clumped heterochromatin, while the Lymphoblast has a vesicular nucleus.
94
What is the nuclear shape of a mature monocyte?
indented or kidney-shaped.
95
How does the cytoplasm of a mature monocyte compare to that of an immature monocyte?
It is less basophilic and appears blue-gray instead of bright blue.
96
What is the primary distinguishing feature of a Small Lymphocyte’s nucleus?
It has very condensed chromatin with little cytoplasm.
97
Which mononuclear cell type retains nucleoli as it matures?
Monocytes
98
how do nucleoli change in the lymphoid series as cells mature?
Nucleoli are prominent in lymphoblasts, less apparent in prolymphocytes, and absent in small lymphocytes.
98
What is the general shape of a Megakaryoblast?
spherical to oval in shape.
98
How does the nucleus of a Megakaryoblast appear?
It is red, finely granular, and contains several nucleoli.
99
What feature gives the Promegakaryocyte an irregular outline?
The numerous cytoplasmic buds present on its surface.
100
How does the size of a Promegakaryocyte compare to a Megakaryoblast?
The Promegakaryocyte is larger than the Megakaryoblast.
101
Which cell in the thrombocytic series is the largest?
Megakaryocyte
101
What nuclear characteristics help identify a Promegakaryocyte?
It has a single, indented, or lobulated nucleus with clumped chromatin and one or two nucleoli.
102
How do platelets form from a Megakaryocyte?
By an exocytotic process where platelets pinch off from the cell surface.
103
Where do platelets appear in relation to the Megakaryocyte?
They appear at the periphery of the Megakaryocyte.
104
What is the cytoplasmic composition of a Megakaryocyte?
It is rich in ribosomes and contains specific granules.
105
What surrounds platelets once they are shed from a Megakaryocyte?
They are completely invested by a unit membrane.
106
A patient presents with severe blood loss, but a bone marrow biopsy reveals an abundance of adipose tissue. What could explain this, and how might the body respond?
the presence of adipose tissue suggests yellow bone marrow, which can revert to active red bone marrow under stress conditions like severe blood loss to increase blood cell production.
107
A cell in the granulocytic series has a kidney-shaped nucleus and a cytoplasm filled with specific granules. Is this cell capable of mitosis?
No, this describes a metamyelocyte, which is post-mitotic and cannot divide anymore.
108
Why do erythrocytes become smaller as they mature, whereas megakaryocytes become larger?
Erythrocytes lose organelles and extrude their nucleus, leading to a compact, efficient oxygen carrier. In contrast, megakaryocytes grow larger to fragment into thousands of platelets.
109
If a cell has both RNA (causing basophilia) and hemoglobin (causing acidophilia) in its cytoplasm, what stage of erythropoiesis is it in?
Polychromatic rubricyte
110
A bone marrow sample shows a large, velvety nucleus with finely reticular chromatin and two pale blue nucleoli. Which hematopoietic lineage is this from?
Granulocytic series, specifically a myeloblast
111
Why do lymphocytes require a different stem cell lineage (CFU-LH) compared to granulocytes and monocytes (CFU-GM)?
Because lymphocytes develop in both the bone marrow and lymphatic organs, whereas granulocytes and monocytes mature primarily within the bone marrow.
112
If a circulating blood cell has azurophilic granules but no specific granules, which cell type is it?
A monocyte, because it contains azurophilic (nonspecific) granules but lacks the specific granules seen in granulocytes.
113
A bone marrow smear reveals a very large cell with cytoplasmic buds, clumped chromatin, and a lobulated nucleus. What is this cell, and what will it produce?
It is a promegakaryocyte or megakaryocyte, responsible for producing platelets.
114
If a granulocytic precursor has granules of different colors in its cytoplasm, what does this indicate?
It is a promyelocyte, as it contains a mix of immature azurophilic granules and developing specific granules, which stain differently.
115
Where do lymphocytes originate during embryonic life?
Yolk sac, liver, and spleen.
115
In mammals, where do B-cells differentiate before moving to peripheral lymphoid organs?
Bone marrow
115
Which organ is responsible for T-cell maturation?
Thymus
116
What is the equivalent of the mammalian bone marrow for B-cell development in birds?
Bursa of Fabricius
117
In which lymphatic organ do T-cells mainly reside?
Paracortical zone of lymph nodes.
118
If mammals lack a Bursa of Fabricius, where do their B-cells develop instead?
Bone marrow
119
If a stem cell stays in the bone marrow and does not migrate to the thymus, what type of lymphocyte will it most likely become?
B-lymphocyte
120
Which lymphocyte type matures in the thymus before migrating to secondary lymphatic organs?
T-lymphocytes.
121
Why don’t mammals need a Bursa of Fabricius for B-cell development?
Because B-cells develop directly in the bone marrow.
122
In which lymphatic structure do B-cells mainly reside?
Lymphoid follicles.
123
What would happen if a developing lymphocyte fails to migrate to the thymus?
It won’t develop into a T-lymphocyte.
124
During embryonic development, lymphocytes originate from multiple sites before the bone marrow takes over. If a mammalian embryo has a genetic defect preventing liver hematopoiesis, which alternative site might compensate for early lymphocyte production?
yolk sac and spleen
125
How long do canine erythrocytes last?
120 days.
125
Which domestic species has the longest erythrocyte lifespan?
Bovine (159 days)
126
If the paracortical zone of lymph nodes is severely depleted, which lymphocyte population is likely deficient?
T-lymphocytes
127
What is the lifespan of feline erythrocytes?
73 days
127
Which species has the shortest erythrocyte lifespan?
Porcine (67 days).
128
128
Which species has an erythrocyte lifespan of 145 days?
Equine (horse)
129
Which organ removes aging erythrocytes from circulation?
Spleen
130
Which animal’s erythrocytes last longer: a goat or a pig?
Goat (125 days vs. 67 days).
131
Which two species have erythrocyte lifespans that are closest in duration?
Canine (120 days) and Caprine (125 days)
132
If a horse’s RBCs last 145 days and a cow’s last 159 days, what is the difference in their RBC lifespans?
14
133
If a cat's erythrocyte lasts 73 days and a horse’s lasts 145 days, whose RBCs are more than twice as long-lived?
Horse
134
What system is responsible for removing old erythrocytes?
Reticuloendothelial system (RES)
134
Which organ primarily removes aging erythrocytes from circulation?
Spleen
134
What must balance erythropoiesis to maintain a steady red blood cell count?
Erythroclasia
135
Where do neutrophils proliferate and mature?
Bone marrow
136
How long is the half-life of neutrophils in circulation?
6 hours
136
How often is the circulating neutrophil pool replaced?
Every 10-12 hours
136
Can neutrophils return to circulation after entering tissues?
no
137
How long does the canine bone marrow reserve pool of neutrophils last?
5 days
138
How long does eosinophil production take?
3-6 days
139
How many eosinophils are in the maturation pool compared to one circulating eosinophil?
300
140
how many eosinophils are in the proliferating pool compared to one circulating eosinophil?
100
141
What is the lifespan of basophils?
10-12 days.
142
Which type of lymphocyte can remain in the body for months or years?
T-lymphocytes
143
What is the lifespan of thymocytes?
3-4 days.
144
Are B-lymphocytes long-lived or short-lived?
Short-lived
144
How long does it take for large and medium B-lymphocytes to regenerate?
8 hours.
145
How long does it take for small B-lymphocytes to regenerate?
At least 4 days
146
How much larger is the marginal pool of monocytes compared to the circulating pool?
5 times larger.
147
Do young monocytes spend a long time in the bone marrow?
no
148
How much larger is the tissue pool of histiocytes compared to circulating monocytes?
400 times greater
148
Where do monocytes randomly enter after leaving circulation?
tissues
149
What is the circulating half-life of human monocytes?
8 days.
149
What is the estimated lifespan of histiocytes?
More than 100 days.
150
What is the process of stopping blood loss called?
Hemostasis
151
What is another term for hemostasis?
Blood clotting
152
If erythropoiesis outpaces erythroclasia, what condition might develop?
Polycythemia (excess RBCs)
153
If the circulating neutrophil pool is replaced every 10-12 hours, how many times is it replaced in a day?
About 2 to 2.4 times per day.
154
Which organ plays a major role in removing aging erythrocytes but is not the site of their production?
spleen
155
A dog has a severe infection. Which bone marrow pool is responsible for supplying extra neutrophils?
The reserve pool.
156
Why do neutrophils have such a short lifespan in circulation?
Because they are rapidly recruited into tissues to fight infections.
157
If eosinophil numbers increase in blood tests, what condition might be suspected?
Allergies or parasitic infections.
158
If the tissue pool of histiocytes is 400 times greater than circulating monocytes, why are there so few monocytes in the blood?
Because most mature into tissue macrophages, where they are needed long-term.
158
Basophils live for 10-12 days. Why might this be necessary for their function?
They help with long-term immune responses, such as allergic reactions.
158
What would happen if hemostasis fails to occur after an injury?
Uncontrolled bleeding (hemorrhage).
