Lecture 7:a.Hematopoiesis & Bone Marrow; b.Thymus Flashcards
(101 cards)
1
Q
Which organs are primary lymphoid organs (2)? What cells do they produce?
A
- Thymus = T cells
- Bone marrow = B cells
2
Q
Which organs and tissue are secondary lymphoid organs and tissues (5)?
A
- Diffuse lymphatic tissue (e.g. GALT)
- Lymphatic nodules
- tonsils
- Lymph nodes
- Spleen
3
Q
Where are T cells found?
A
Thymus
4
Q
Where are B cells found?
A
Bone marrow and gut associated lymphatic tissues (GALT) in humans
5
Q
After birth, where does hemopoiesis occur?
A
occurs only in red bone marrow and lymphatic tissues
6
Q
Explain the 3 phases/stages of fetal hemopoiesis
A
- 1st phase: Embryonic yolk sac = formation of blood islands (RBCs only)
- 2nd phase:liver: red and some WBCs
- 3rd phase: Bone marrow = RBCs and WBCs, also spleen and lymphatic organs
7
Q
What are the two types of bone marrow? Which one is active and inactive? What do they produce?
A
- Red marrow = active, produce blood cells
- Yellow marrow = inactive, produce fat cells
8
Q
What makes up red marrow (3)?
A
- stroma (reticular cells) = produce fibers, contain fibroblasts and macrophages
- blood-forming cords (hematopoietic cord)
- endothelial-lined sinusoids (discontinuous capillaries)
9
Q
Newborns have which type of bone marrow?
A
red
10
Q
Where are lymphocytes formed?
A
formed in red bone marrow and in the lymphatic tissues
11
Q
Explain steps of bone marrow aspiration(3)
A
- needle inserted into hip bone (preferred anatomical site)
- small amount of bone marrow obtained
- aspirate is spread on a glass slide
12
Q
Explain steps of bone marrow core biopsy (3)
A
- intact bone marrow is obtained by a small incision in the skin
- biopsy needle is inserted into bone using a corkscrew movement to obtain a solid piece of bone marrow
- biopsy is used to diagnose and stage different types of cancer or monitor the results of chemotherapy
13
Q
Which cells are the last cell capable of mitosis (endomitosis)?
A
Megakaryoblasts = chromosome replication
14
Q
Under hormone stimulation by ______ causes a megakaryoblast to become a megakaryocyte (platelet-producing).
A
thrombopoietin
15
Q
Where do platelets originate in adults?
A
red bone marrow by fragmentation of the cytoplasm of mature megakaryocytes
16
Q
List stages of erythrocyte lineage (erythropoiesis) (6)
“Powerful Businesses Pollute Our Reeling Environment”
A
- Proerythroblast
- Basophilic erythroblast
- Polychromatophilic erythroblast (last mitosis)
- Orthochromatophilic erythroblasts aka normoblast
- Reticulocyte
- Erythrocyte
“Powerful Businesses Pollute Our Reeling Environment”
All blasts are still mitotically active and can further differentiate
17
Q
RBCs develop from the multipotential ______ stem cell in bone marrow under the influence of ____ and some cytokines.
A
- myeloid
- erythropoietin
18
Q
What are the major changes during the process of erythrocyte maturation (6)?
A
- Cell volume decreases
- Nucleoli diminish in size until they become invisible under LM
- Nuclear diameter decreases
- Chromatin becomes increasingly dense = thickened and reduced in size and finally extruded from the cell
- Cytoplasmic basophilia (ribosomes) decrease while acidophilia (hemoglobin) simultaneously increases
19
Q
How many days does it take RBCs to develop?
A
7 days
20
Q
How many days do RBCs circulate in the blood?
A
120 days
21
Q
What occurs when a proerythroblast transitions to an erythrocyte (2)?
A
- increase in cytoplasmic hemoglobin concentration
- decrease in nuclear volume and an increase in chromatin condensation followed by extrusion of a pyknotic nucleus
22
Q
Explain the process of a reticulocyte becoming a mature erythrocyte
A
Reticulocyte will leave the bone marrow, pass to bloodstream, lose its mitochondria and ribosomes within 1-2 days = becomes a mature erythrocyte
23
Q
What are the possible pathological causes involving RBCs (4)?
A
- anemia
- thalassemia
- miliary tuberculosis
- cancers involving bone marrow (myelomas, leukemias, lymphomas) and chronic hypoxemia
24
Q
What are the 5 stages of leukopoiesis?
“My Physician Makes Me Better”
A
- Myeoblast
- Promyelocyte = largest cell, primary azurophilic granules only produced in this stage
- Myelocyte (neutrophilic,eosinophilic,basophilic) = primary (azurophilic) granules + secondary (specific) granules produced (1st time secondary granules are produced)
- Metamylocyte(only in neutrophils and eosinophils) = nucleus is kidney shaped
- Band cell = only in neutrophils
Mature granulocyte = 1st sign of the development of neutrophil, eosinophil, basophil
“My Physician Makes Me Better”
25
Where are monocytes produced?
in bone marrow from a biopotential stem cell
26
**What is aplastic anemia also called?**
hypocellular bone marrow
27
What is **Aplastic Anemia (marked w/ pancytopenia)**?
reduction in the # of erythrocytes, all WBCs, and platelets in blood circulation
28
**What causes aplastic anemia (aka hypocellular bone marrow)?**
* Many cases are idopathic = unknown
* Some can follow toxic exposure to chemotherapy drugs or to chemicals such as benzene, radiation, and infection with viral hepatitis
29
**How is aplastic anemia (aka hypocellular bone marrow) treated?**
* bone marrow transplantation
* anti-lymphocyte globulin (in idopathic cases)
30
**What is the function of the thymus?**
* primary lymphatic organ
* educates thymocytes (before becoming T-cells)
31
**What makes up the structure of the thymus?**
* poorly developed capsule
* **epithelioreticular cells (aka nurse cells) = responsible for development and maturation of T-cells**
* few fibers
* No lymphatic nodules = no interaction with B cells
32
**What is the function of Hassall's corpuscle (thymic corpuscle)?**
produce interleukins that function in differentiation and education of T cells
33
How do mature T cells (CD8+ and CD4+) leave the cortex?
through postcapillary venules in medulla and enter the blood circulation
34
What is DiGeorge Syndrome?
an inherited immunodeficiency disease
35
What causes DiGeorge Syndrome?
* the cortical epithelial (epithelioreticular) cells did not develop = thymus is underdeveloped = no T cell education b/c lack of epithelioreticular cells
36
What is the result of DiGeorge Syndrome?
* lack of cell-mediated immunity (low T cell count)
* loss of parathyroid gland and cardiac abnormalities
37
**Identify the cell circled**
megakaryocyte
38
Identify the structure that the arrow is pointing to
hemapoietic cords
39
**Identify cell #1**
megakaryocyte
40
Identify cell #2
adipocyte
41
What structure is #3 and #4?
sinusoid capillary
42
What cell is #1?
promyelocyte
43
What cell is #2?
neutrophilic myelocyte
44
Identify cell #4 and #5
neutrophilic metamyelocyte
45
Identify cell #6 and #7
orthochromatic erythroblast
46
Identify the cell labelled as #8
mature segmented neutrophil
47
Identify the cell labelled as #9
band cell (neutrophil)
48
Identify cell #1
eosinophilic metamyelocyte
49
What structure is #1?
cortex
50
What structure is labelled as #2?
medulla
51
Identify #1
orthochromatic erythroblast (aka normoblast)
52
Identify #2
band cell (neutrophil)
53
Identify #3
mature neutrophil
54
Identify #4
Neutrophilic metamyelocytes
55
Identify #5
neutrophilic metamyelocytes
56
Identify #6
neutrophilic myelocyte
57
Identify #7
neutrophilic metamyelocyte
58
What cell is #1 pointing to?
late polychromatic erythroblast
59
What cell is #2 pointing to?
eosinophilic myelocyte
60
What cell is #3 pointing to (blue arrow)?
late neutrophilic myelocyte
61
Identify #4
orthochromatic erythroblast (aka normoblast)
62
What cell is #5?
band cell (neutrophil)
63
What cell is #6?
polychromatic erythroblast
64
Identify cell #1
polychromatic erythroblast
65
Identify cell #2
late polychromatic erythroblast
66
Identify cell #3 (bright pink arrow)
polychromatic erythroblast
67
Identify cell #4
orthochromatic erythroblast
68
What cell is #1 (pink arrow)?
basophilic erythroblast
69
What cell is #2 (blue arrow) ?
promyelocyte
70
What cell is #3?
neutrophilic myelocyte
71
What cell is #4?
neutrophilic myelocyte
72
**What type of cell is #1?**
thymic (medullary) epithelioreticular cell
73
**What structure is #2?**
Hassall's corpuscle
74
What cell is #3?
neutrophilic myelocyte
75
What cell is #4?
neutrophilic metamyelocyte
76
What cell is #5?
band cell (neutrophilic)
77
What cell is #6?
mature neutrophil
78
What cell is #7?
promyelocyte
79
What structure is #1?
capsule
80
What are the structures labelled as #2?
cortex
81
What structures are labelled as #3?
medulla
82
What structure is #4?
thymic corpuscle
83
What structure is #5?
Hassall's corpuscle
84
What cell is #1?
neutrophilic series
85
What cell is #2?
eosinophilic myelocyte = very pink granules
86
What cells are #3?
myelocyte
87
What cell is #4?
metamyelocyte
88
What cell is #5?
band cell (neutrophil)
89
**What structure is #1?**
capsule
90
**What structure is #2?**
trabecula
91
**What structure is #3?**
cortex
92
**What structure is #4?**
blood vessel
93
**What structure is #5?**
* Hassall's corpuscle
* in medulla of thymus
* unique to thymus
94
What is a neutrophilic myelocyte?
the first sign of the development of a specific type of granulocyte series = neutrophilic, eosinophilic, or basophilic
95
1. Which of the following cell types is responsible for the maturation and development of thymocytes?
a. Reticulocytes
b. Epithelioreticular cells
c. Fibroblasts
d. Macrophages
b. Epithelioreticular cells
96
2. Identify the cell:
a. Neutrophilic myelocyte
b. Basophilic erythroblast
c. Neutrophilic metamyelocyte
d. Basophilic myelocyte
c. Neutrophilic metamyelocyte
97
3. Which of the following statements is true about the maturation of erythrocytes?
a. Decrease of cytoplasmic acidophilia & increase in cytoplasmic basophilia
b. Reduction in number of azurophilic granules & increase in nuclear volume
c. Increase of cytoplasmic RNA & decrease in cytoplasmic hemoglobin
d. Decrease in cytoplasmic RNA & increase in cytoplasmic acidophilia
d. Decrease in cytoplasmic RNA & increase in cytoplasmic acidophilia
98
4. Which cell type, involved in the stages of erythropoiesis, marks the final stage of maturation in which the nucleus is still present?
a. Proerythroblast
b. Orthochromatophilic erythroblast
c. Polychromatic erythroblast
d. Reticulocyte
b. Orthochromatophilic erythroblast
99
5. Which feature distinguishes myelocytes from promyelocytes?
a. Specific granules
b. Lobulated nucleus
c. Azurophilic granules
d. Basophilic cytoplasm
a. Specific granules
100
6. Identify the cell:
a. Band neutrophil
b. Orthochromatophilic erythroblast (normoblast)
c. Basophilic erythroblast
d. Neutrophilic myelocyte
c. Basophilic erythroblast
101
7. Identify the cell:
a. Band neutrophil
b. Orthochromatophilic erythroblast (normoblast)
c. Basophilic erythroblast
d. Neutrophilic myelocyte
b. Orthochromatophilic erythroblast (normoblast)
