5. Erythropoiesis Flashcards
(172 cards)
1
Q
The term for RBC formation
A
Erythropoiesis
2
Q
Total mass of RBCs circulating in the peripheral blood and the bone marrow RBC precursors.
A
Erythron
3
Q
Erythrocytes in the circulation
A
RBC mass
4
Q
A term that describes the dynamics of RBC creation and destruction
A
Erythrokinetics
5
Q
Production of defective erythroid precursors
A
Ineffective erythropoiesis
6
Q
2 examples of macrocytic, normochromic anemias caused by ineffective erythropoiesis
A
folate deficiency
vitamin b12 deficiency
7
Q
Ineffective erythropoiesis causes defective RBC precursor cells to undergo _____ in the bone marrow before they even mature to the reticulocyte cells.
A
apoptosis
8
Q
2 examples of microcytic, hypochromic anemias due to ineffective erythropoiesis
A
thalassemia
sideroblastic anemia
9
Q
Decrease in the number of RBC precursors in the bone marrow resulting in decreased RBC production
A
insufficient erythropoiesis
10
Q
what type of anemia is iron deficiency
A
microcytic, hypochromic
11
Q
type of anemia of acute leukemia and renal disease
A
normocytic, normochromic
12
Q
examples of conditions that resulted from insufficient erythropoiesis
A
iron deficiency anemia
acute leukemia
renal disease
13
Q
immature hematopoietic stem cells that is committed to a cell line but cannot be identified morphologically
A
progenitor cells
14
Q
immature HSCs that are morphologically identifiable or belonging to a given cell line
A
15
Q
immature HSCs that are morphologically identifiable or belonging to a given cell line
A
precursor cells
16
Q
a transferrin receptor and also the earliest marker of erythroid differentiation
A
CD71
17
Q
progenitor vs precursor
A
progenitor: morphologically unidentifiable
precursor: morphologically identifiable
18
Q
How to measure RBC Survival
A
- Collect px blood sample
- Label RBCs with Chromium-51
- Inactivate excess Chromium-51 in plasma
- Reinject labeled RBCs to px
- Measure radioactivity of RBCs at intervals until 50% of activity has disappeared
19
Q
The results for RBC survival are commonly expressed as
A
Chromium-51 half-survival time
20
Q
Normal range for RBC survival range
A
28-38 days
21
Q
Chief stimulatory cytokine for RBCs
A
Erythropoietin
22
Q
EPO is the major hormone that stimulates the production of _____
A
RBCs
23
Q
T/F
EPO is a thermolabile, dialyzable, glycoprotein hormone
A
False. Thermostable and non-dialyzable
24
Q
Primary cell source of EPO
A
peritubular interstitial cells of the kidneys
25
primary target cells of EPO
BFU-E
CFU-E
26
Normally, EPO is released into the blood in response to
hypoxia
27
3 major effects of EPO
1. early release of reticulocytes from BM
2. reduce time needed for RBCs to mature in BM
3. prevent apoptotic cell death
28
apoptosis rescue by EPO is the major way of increasing
RBC mass
29
Blood doping can lead to
deadly arterial and venous thrombosis
30
Illegally done by some athletes; done by using EPO injections to increase the oxygen-carrying capacity of their body
Blood doping
31
Blood doping is illegally done by some athletes to increase
stamina and endurance
32
Growth hormone and prolactin are released by
pituitary gland
33
Growth hormone and prolactin stimulates erythropoiesis _______
directly
34
Testosterone is released by the
testes
35
Estrogen is released by the
ovaries
36
estrogen inhibits erythropoiesis ______
indirectly
37
testosterone stimulates erythropoiesis _______
indirectly
38
This is the reason why men have higher threshold values for Hgb, Hct, and RBC count.
Men have testosterone. Testosterone stimulates erythropoiesis.
Women have estrogen. Estrogen inhibits erythropoiesis.
39
T/F
Menstruation is the main reason why women have lower threshold values for Hct, Hgb, and RBC count.
False
40
committed erythroid progenitor cells
BFU-E
CFU-E
41
BFU-E means
burst forming unit-erythroid
42
CFU-E means
colony forming unit-erythroid
43
How long does it take for the BFU-E to mature to an erythrocyte
18-21 days
44
____ are spent as recognizable precursor in the BM
6 days
45
Rubri nomenclature
Rubriblast-Prorubricyte-Rubricyte-Metarubricyte-Reticulocyte-Mature RBC
46
Normoblast nomenclature
Pronormoblast
Basophilic normoblast
Polychromatophilic normoblast
Orthochromatic normoblast
Reticulocyte
Mature RBC
47
Erythroblast nomenclature
Proerythroblast
Basophilic erythroblast
Polychromatophilic erythroblast
Orthochromatic erythroblast
Reticulocyte
Mature RBC
48
When reticulocytes are found in a wright-stained smear, they are called
polychromatophilic erythrocytes
diffusely basophilic erythrocytes
49
When diffusely basophilic erythrocytes are found using a supravital stain, they are called
reticulocytes
50
Rubriblast is also called
Pronormoblast
Proerythroblast
51
Rubriblast size
12-20 um
52
Number of nucleoli of rubriblast
1-2
53
rubriblast n:c ratio
8:1
54
a morphologic feature used to identify and stage RBC and WBC precursors; also a visual estimate of what area of the cell is occupied by the nucleus compared with the cytoplasm
n:c ratio
55
Rubriblast gives rise to
2 prorubricytes
56
The earliest recognizable RBC precursor using light microscope
Rubriblast/Pronormoblast/Proerythroblast
57
If the areas occupied by the nucleus and the cytoplasm are approximately equal, the N:C ratio is
1:1
58
If the nucleus takes up <50% of the area of the cell, the ratio is
lower
59
If the nucleus takes up >50% of the area of the cell, the ratio is
higher
60
refers to the blue part of the cell and is due to the acidic components
basophilic
61
refers to the pink part of the cell and is due to the basic components
Acidophilic
62
the degree of cytoplasmic basophilia correlates with the quantity of
ribosomal RNA
63
As the RBC matures, the eosinophilia of the cytoplasm correlates with the accumulation of
hemoglobin
64
Prorubricyte other names
Basophilic Normoblast
Early Normoblast
Basophilic Erythroblast
Early Erythroblast
65
size of prorubricyte
10-15 um
66
# of nucleoli of early normoblast
0-1
67
N:C ratio of Basophilic Erythroblast
6:1
68
Most helpful criteria in distinguishing early normoblast from proerythroblast
coarser chromatin
absent nucleoli
69
Basophilic normoblast is the last stage with a
nucleolus
70
Prorubricyte is the first stage of
hemoglobinization
71
Rubricyte other names
Polychromatophilic normoblast
Intermediate normoblast
Polychromatophilic erythroblast
Intermediate Erythroblast
72
Intermediate normoblast size
10-12 um
73
# of nucleolus of intermediate erythroblast
0
74
N:C ratio of Polychromatophilic normoblast
4:1
75
The prorubricyte gives rise to
4 rubricytes
76
Each rubricyte gives rise to
2 metarubricytes
77
What RBC precursor is commonly confused with lymphocyte
Polychromatic normoblast
78
lymphocyte vs rubricyte
Lym nucleus: crushed velvet; cytoplasm: sky blue, "robin's egg" blue
Rubricyte nucleus: checkerboard; cytoplasm: muddy/gray
79
This RBC precursor is the last stage to undergo mitosis
Intermediate erythroblast
80
The first stage where the pink color caused by recent hemoglobinization first manifests
Rubricyte
81
Metarubricyte other names
Orthochromatic normoblast
Late normoblast
Acidophilic normoblast
Orthochromatic erythroblast
Late erythroblast
Pyknotic erythroblast
Nucleated red blood cells
82
The nucleus is _____ during the pyknotic erythroblast phase
extruded
83
Last RBC precursor to have a nucleus
Acidophilic normoblast
84
size of late erythroblast
8-10 um
85
# of nucleolus of late normoblast
0
86
color of orthochromatic erythroblast's cytoplasm
salmon-pink
87
N:C ratio of Orthochromatic normoblast
1:2
88
Enveloped extruded nucleus engulfed by bone marrow macrophages
pyrenocyte
89
Frequently, small fragments of the nucleus are left behind if the nRBC projection is pinched off before the entire nucleus is enveloped. These small fragments are called
Howell-Jolly bodies
90
Howell-Jolly bodies are removed from the RBCs by the spleen thru
pitting
91
Young RBCs containing residual RNA
Reticulocyte
92
size of reticulocyte
8-10 um
93
What RBC precursor has the same size?
Metarubricyte
Reticulocyte
94
# of nucleolus of reticulocyte
0
95
T/F
Reticulocyte has a nucleus
False
96
Last immature erythrocyte stage
Reticulocyte
97
Reticulocytes spend _____ in the bone marrow and ____ in the peripheral blood before developing into a mature RBC
2-3 days
1 day
98
2 types of reticulocytes
shift cells
stress reticulocytes
99
These reticulocytes are seen in cases with increased RBC production.
Shift cells/polychromatophilic macrocyte
100
These reticulocytes are seen in severe conditions like hemolytic anemia
Stress reticulocytes/ Macroreticulocytes
101
The last stage of hemoglobin synthesis
Reticulocytes
102
Reticulocyte count is used to diagnose the type of _____ present in a patient
anemia
103
size of mature rbc
7-8 um
104
shape of mature rbc
biconcave disk
105
thickness of rbc
1.5-2.5 um
106
Average life span of rbc
120 days
107
number of rbcs produced from 1 rubriblast
16
108
Normal ratio of RBCs to WBCs
600:1
109
Normal ratio of RBCs to platelets
15:1
110
Adult RBC contains no mitochondria, therefore there is no
protein, hemoglobin synthesis
111
Central pallor of mature RBC occupies ____ of the cell's diameter1
1/3
112
Major macromolecule that constitutes the RBC membrane
Proteins (peripheral and integral) 52%
113
Other RBC constituents aside from proteins
lipids 40%
CHO 8%
114
Provides the vertical support connecting the bilayer to the underlying cytoskeleton to maintain RBC membrane integrity
transmembrane proteins
115
An integral protein that transports water
Auaporin 1
116
An integral protein that transports anion and supports ABH antigens
Band 3
117
Ca2+-ATPase transports
Ca2+
118
Supports Fy antigen
Duffy
119
Glucose transporter and supports ABH antigen
Glut-1
120
Transports negatively charged sialic acid (3)
Glycophorin A
Glycophorin B
Glycophorin C
121
Different functions of 3 integral proteins that transports negatively charged sialic acid
GA: supports MN determinants
GB: supports Ss determinants
GC: supports Gerbich system determinants
122
a transmembrane protein that is responsible for integrin adhesion
ICAM-4
123
Zn2+-binding peptidase, K antigens
Kell
124
Integral protein Jk transports
urea
125
D and CcEe antigens
Rh
126
D and CcEe antigens
Rh
127
This is necessary for expression of D and CcEe antigens, also transports gas i.e. CO2
RhAG
128
Proteins that provide the horizontal support for the membrane.
Skeletal/Cytoskeletal/Peripheral Proteins
129
The shape and flexibility of the RBC depends on the
cytoskeleton
130
primary skeletal proteins
a-spectrin
b-spectrin
131
caps actin filament
adducin
tropomodulin
132
Ankyrin anchors (2)
band 3 and protein 4.2
133
actin building protein
dematin
134
F-actin binds
b-spectrin
135
anchors 4.1 complex
protein 4.1
136
protein 4.2 anchors
ankyrin complex
137
regulates actin polymerization
tropomyosin
138
Defect in protein(s) that disturbs vertical membrane interactions between transmembrane proteins and underlying cytoskeleton; loss of membrane and decreased surface area-to-volume ratio.
Heredirary Spherocytosis
139
Inheritance pattern of hereditary spherocytosis
autosomal dominant
140
deficient proteins in hereditary spherocytosis (5)
ankyrin
band 3
a-spectrin
b-spectrin
protein 4.2
141
this rbc index is elevated in hereditary spherocytosis
Mean Corpuscular Hgb Concentration
142
Normal MCHC range
31-37 g/dL
143
MCHC of px with HS
35-38 g/dL
144
What is the only disease that is characterized by high MCHC?
Hereditary Spherocytosis
145
T/F
In HS px, the rbc membrane is elastic, but is less stretchable
FALSE.
stretchable, less elastic
146
Spherocytes gather this electrolyte( ?) at a higher rate than normal RBCs in the spleen; leading to a decreased tolerance to osmotic changes because they ---- then lyse.
Na
swell
147
What surgical procedure is beneficial to px with HS
splenectomy
148
Most sensitive and specific test to confirm the diagnosis of HS
Eosin-5′-maleimide (EMA) binding test
149
principle of EMA binding test
flow cytometry
150
Defect in proteins that destroy the horizontal linkages in the protein cytoskeleton which results to the loss of mechanical stability of membrane
Hereditary elliptocytosis
151
Inheritance pattern of hereditary spherocytosis
Autosomal dominant
152
deficient proteins in HE (3)
a-spectrin
b-spectrin
Protein 4.1
153
A rare subtype of hereditary elliptocytosis that has an autosomal recessive pattern
Hereditary pyropoikilocytosis
154
deficient proteins in hereditary pyropoikilocytosis
a-spectrin
b-spectrin
155
Severe defect in spectrin the disrupts horizontal linkages in protein cytoskeleton; severe RBC fragmentation
Hereditary pyropoikilocytosis
156
Hereditary ovalocytosis is also known as
Southeast Asian ovalocytosis
157
inheritance pattern of hereditary ovalocytosis
autosomal dominant
158
defective protein in southeast asian ovalocytosis
band 3
159
Defect in band 3 causing increased membrane rigidity; resistant to malaria; prevalent in some areas of SEA
hereditary ovalocytosis
160
Overhydrated hereditary stomatocytosis causes increased membrane permeability to
Na
K
161
hereditary pattern of overhydrated hereditary stomatocytosis
autosomal dominant
162
deficient proteins in overhydrated hereditary stomatocytosis
Rh-associated protein (RHAG)
others unknown
163
In OHS increased intracellular Na causes influx of H2O, increase in cell volume, and decreased cytoplasmic viscosity. This further results to what RBC morphology
stomatocytes (5-50%)
macrocytes
164
The most common form of stomatocytosis
Dehydrated hereditary stomatocytosis
165
Dehydrated hereditary stomatocytosis is also known as
Hereditary Xerocytosis
166
Inheritance pattern of hereditary xerocytosis
autosomal dominant
167
deficient protein in hereditary xerocytosis
piezo-type mechanosensitive ion channel component 1
168
In HX, there is increased permeability to (ELEC?) leading to a decrease in this intracellular electrolyte
K
169
A decrease in intracellular K results to
loss of water from cell
decrease in cell volume
increased cytoplasmic viscosity
170
Typical RBC morphology in HX
Codocytes
Burr cells
Stomatocytes (<10%)
RBCs with puddled Hgb at periphery
dessicated cells with spicules
171
HS, HE, HP, HO/SEAHO are caused by mutations that change
membrane structure
172
OHS, DHS/HX are caused by mutations that change
membrane transport proteins
