The Erythrocyte Flashcards
1
Q
 overall, as normal RBCs mature what changes are seen?
A
-cell size decrease
-nuclear chromatin pattern becomes denser
-Nucleoli disappear
-amount and color of cytoplasm changes
-size of nucleus decreases greater than the size of the cell (N:C) ratio 
2
Q
Production of total population of mature red blood cells and their precursors in blood, bone marrow, and other sites.
A
Erythropoiesis 
3
Q
When viable red blood cells (Both in number and quality) are delivered to the circulation to function effectively
A
Effective erythropoiesis
4
Q
How is effective erythropoiesis measured?
A
By reticulocyte (retic) and total RBC counts
5
Q
When RBCs are unable to deliver sufficient O2 to the tissues (Either due to numbers or quality) resulting in anemia, thus causing hypoxia
A
Ineffective erythropoiesis
6
Q
A decrease in circulating RBC mass and/or Hemoglobin content
A
Anemia
7
Q
Lack of oxygen in body tissues
A
Hypoxia
8
Q
______________ are the primary site for storage of iron in the bone marrow (nurse cell)
A
Macrophages
9
Q
_____________ is the protein that binds and transports iron to either storage or developing red blood cells
A
Transferrin
10
Q
______________ cells are the lining cells of the bone marrow and blood vessels. 
A
Endothelial
11
Q
What are the six stages of RBC naturation/amplification?
A
• Pronormoblast (rubriblast or Proerythroblast) “-blast”
• basophilic normoblast
• polychromatic normoblast
• orthochromic normoblast
• reticulocyte “retic-“
• Erythrocyte
12
Q
What is the size of a pronormobalst (blast)? 
A
12-20 micrometers
13
Q
What is the N:C ratio for pronormoblast (blasts)?
A
High ratio at 8:1
14
Q
Contains nucleoli and fine chromatin, round to slightly oval shape 
A
”blast”
15
Q
cytoplasm: Very basophilic (High RNA content, lots of organelles), with lighter staining perinuclear area around Golgi (not always visible) 
Very blue
A
“Blast”
16
Q
What is the size of basophilic Normoblasts? 
A
10-15 Micrometers
17
Q
Nucleus Is round, coarser chromatin, no visible Nucleoli*
A
Basophilic normoblast 
18
Q
Cytoplasm temporary even more basophilic (Royal blue); Golgi may be visible as light area near nucleus
A
Basophilic normoblast 
19
Q
What is the N:C ratio for Basophilic normoblasts? 
A
6:1
20
Q
Can hemoglobin be seen in the basophilic normoblast stage? 
A
Hemoglobin is being synthesized but cannot be seen yet, Can only see RNA at this stage
21
Q
What is the size of polychromatic normoblasts? 
A
10-12 micrometers
22
Q
The nucleus is round, sometimes eccentric, smaller, with coarser chromatin 
A
Polychromatic normoblast 
23
Q
What is the first stage you can see hemoglobin?
A
Polychromatic normoblast 
-gives blue/gray color
24
Q
What is the N:C ratio for polychromatic normoblasts?
A
4:1
25
Cytoplasm is opaque, violet-blue or grayish color (Due to Hgb Synthesis)
*polychromasia 
Polychromatic normoblast 
26
What is the last stage capable of mitosis? 
Polychromatic normoblast 
27
What is the last stage to have a nucleus? 
Orthochromic normoblast
28
What is the size of orthochromic normoblasts?
8-10 micrometers
29
Pyknotic (Degenerated nuclear chromatin, very dark), Eventually extruded
Orthochromic normoblast
30
The cytoplasm is polychromasia (Blue/gray) 
Orthochromic normoblast 
31
Which stage do automated analyzers mistake for WBCs? 
Orthochromic normoblast
32
What percentage of orthochromic normoblasts are scene in circulation?
Only small percentage
33
What is the N:C ratio for Orthochromic normoblast?
1:2
34
What stage is typically called “ Nucleated red” ?
Orthochromic normoblast
35
A WBC count must be corrected if _____ or more Orthochromic normoblasts, “ Nucleated red”, are present on a 100 cell WBC differential
5
36
Immature RBCs are called…
Reticulocytes “retic-“ 
37
What is the cell size of Reticulocytes?
7-9 micrometers (nearly normal)
38
No nucleus present. Varying degrees of polychromasia (Variation in cytoplasmic color, usually a bluish tinge, May have basophilic stippling) 
Reticulocytes
39
”awkward stage” but can still function and deliver oxygen
Reticulocytes
40
What is the basophilic stippling seen in reticulocytes?
Leftover RNA aggregates 
41
Reticulocytes reside in marrow for ___ day(s), And then retained in the spleen for pitting and polishing for a few days, then released as a mature cell
1
42
What is it called when the spleen removes RNA inclusions?
“Pitting” 
43
Do all Reticulocytes show stippling? 
No, but show Polychromasia
44
Reticulocytes are ___________ Larger and bumpier than RBCs
Slightly
45
What is a very old nickname for retics? 
“Shift cell”
-if not visible as basophilic stippling residual RNA can be stained with a supravital stain (“in living sate”), Using either new methylene blue (common) or brilliant cresyl blue stain (rarer) 
46
What stain is used to identify retics? 
New methylene blue
47
What is the cell size of erythrocytes?
7-8 micrometers
48
no nucleus present, has distinctive central pollor; No protein or Hgb made; No mitochondria present
Erythrocyte
49
What is the lifespan of erythrocytes? How far does it travel in that time?
120 days
300 miles
50
The collection of all Erythrocytes throughout the body
erythron
51
Refers only to the cells in circulation (Not in marrow or spleen)
RBC mass
52
Diminished availability of oxygen to the body tissues. Occurs when the oxygen tension in the cells is decreased
Hypoxia
53
EPO Is produced primarily in the kidneys in response to?
Degree of oxygenation
54
What hormone functions to maintain normal RBC mass?
Erythropoietin EPO
55
Initiates a cascade of events that lead to increased RBCs in circulation
EPO
56
What are some of the cascade events caused by EPO? 
-allows early release of reticulocytes
-Increase number of mature erythrocytes
-Reduces marrow transit time
57
An Influx of reticulocytes means that the marrow is functioning….
Normally
58
RBCs are removed from circulation after 120 days by ___________.
Hemolysis (Occurs after decrease RBC flexibility)
59
What is the most common Type of erythrocyte destruction? 
Extravascular hemolysis (Recycles RBCs) 
60
What is the least common type of Erythrocyte destruction ?
Intravascular hemolysis (Occurs within the lumen of blood vessels and cannot be recycled)
61
-Loss of glycolytic enzymes leads to increased sodium and decreased potassium in cell = Spherocytes
-macrophages in spleen and liver (i.e., Reticuloendothelial system)
Extravascular hemolysis
62
Anemia is measured through ______levels 
EPO
63
 What are the two Common causes of anemia? 
Decreased RBC and hemoglobin levels
64
What three elevated levels correlate with increased destruction of RBCs? 
-increase in urobilinogen measured in stool
-Increased serum bilirubin and LDH levels
-Increase serum haptoglobin
65
Measurement of RBC production in destruction can also be assess through what ratio? 
Erythroid marrow M:E ratio
1:1 - hyperplasia
> 4:1 Indicates hypoplastic marrow (not enough RBC produced) 
66
M:E ratio is only used when from ___________ and not Peripheral blood. 
Bone marrow
67

68
What are the four basic functions that the components of the RBC membrane allow it to perform?
-maintain cell shape and deformability
-Maintain osmotic balance between plasma and cell membrane
-Support cell surface antigens/markers
- allow nutrients and iron passage selectively into an out of cell (selective permeability) 
69
More cholesterol in the membrane = 
More rigidity (This will affect the plasma membrane permeability to electrolytes And nonelectrolyte)
This helps to maintain the plasma membranes appropriate surface area to volume ratio
70
What is the composition of RBC membrane?
-lipids (some Glycolipids)
-Cholesterol
-RBC peripheral membrane proteins
-Integral plasma membrane proteins
71
What are the RBC peripheral membrane proteins that line the inner membrane surface?
1. Spectrin (bands 1,2)
2. actin (band 5)
3. Ankyrin
4. Band 4.1
72
(RBC peripheral membrane proteins)
The major component of RBC cytoskeleton. Made of long filamentous rods of alpha and beta subunits, loosely woven together; Has ATPase activity; Contributes to pliancy 
Spectrin (bands 1,2)
73
(RBC Peripheral membrane proteins)
Small globular proteins which work with spectrin filaments
Actin
74
(RBC peripheral membrane protein)
Anchors Band 3
Ankyrin
75
(RBC peripheral membrane protein)
Binds Spectrin to glycophorin C
Band 4.1
76
What is the function of the RBC peripheral membrane proteins?
Underline the lipid bilayer on the cytoplasmic face and directly regulate pm shape and properties. 
* necessary for microcirculation
77
What protein contributes to pliability of the cell, and keeps it elastic and held together?
Spectrin
78
What are the integral p.m. proteins of RBCs? 
1. Band 3
2. Glycophorin A
3. Glycophorin C
79
RBCs are ______________ charged. 
Negatively
80
(integral p.m. protein)
anion Exchange transporter protein for Cl- and HCO3- and Attaches cytoskeleton to phospholipid bilayer 
Band 3 (AE1)
81
(Integral p.m. protein)
Blood group antigen (Ag) Also helps stabilize p.m.
Glycophorin A
82
(integral p.m. protein)
Attaches cytoskeleton to lipid bilayer
Glycophorin C
83
What is the advantage of Zeta potential that repels RBC’s away from each other in circulation? 
Prevents clumping and clotting
84
Band 3 and all the glycophorins are ____________, which help give RBC’s overall negative charge, called Zeta potential.
Sialoglycoprotiens
85
Energy is ______ needed to effect O2 and CO2 exchange through RBC plasma membrane.
NOT
86
What is energy required for in erythrocyte energy metabolism?
-preserve plasma membrane shape
-Maintenance of intracellular gradients
-Maintenance of membrane the phospholipid
-Protection of cell proteins from denaturation
-Initiation and maintenance of glycolysis
87
Erythrocyte energy metabolism involves what metabolic pathways?
*anaerobic glycolysis*
-Embden-Meyerhof Pathway (EMP)
-Methemoglobin Reductase Pathway
-Rapaport-Leubering Pathway (RLP) or Shunt (Unique for a Erythrocytes)
88
What metabolic pathway is responsible for 90 to 95% of cells glucose generation? 
-net gain 2 ATP
-2,3-BPG and NADH
EMP
89
This is a cofactor in maintaining hemoglobin
NADH
90
-This helps with the offloading of oxygen, Regulates oxygen delivery to tissues
-provided in the EMP pathway
2,3-BPG (2,3-bisphosphoglycertate)
91
EMP rate is regulated by….
ATP concentration
Increased ATP = allosteric regulator
Increased ATP = decreased glycolysis 
92
-adjunct pathway to EMP that uses NADH produced from glycolysis*
-This NADH acts as coenzyme for Hgb-M reductase 
Methemoglobin reductase pathway
93
 NADH acts as coenzyme for Hgb-M reductase. What would this enzyme do?
Supports the reduction of methoglobin to hemoglobin
Hgb-M Fe3+ (ferric) —-> Hgb Fe2+ (ferrous)
94
Deficiency of ____________ Causes chronic cyanosis. 
Hgb-M reductase
-Hgb-M levels should never reach >2%
95
What Metabolic pathway is unique to RBCs? 
Rapaport- Luebering Pathway (RLP)
96
This pathway helps regulate oxygen transport inside the RBC by producing 2,3-BPG, an allosteric regulator of Hgb. The presence of this molecule enhances O2 offloading! 
RLP
97
RLP makes….
*** 2,3-BPG
98
What is the aerobic glycolysis Pathway for Erythrocyte metabolism?
Hexose Monophosphate Pathway (HMP) aka Pentose-Phosphate Shunt
99
-this pathway is responsible for 5 to 10% of glucose consumption
-Controlled by Glucose-6-Phosphate Dehydrogenase (this helps Reduce RBC sensitivity to oxidative damage!)
-main purpose is to maintain NADP and reduced glutathione 
(HMP) Hexose Monophosphate Pathway
100
What is the main purpose of HMP? 
-maintain NADP and reduced glutathione 
101
What prevents oxidative damage to RBC’s in the HMP?
G-6-PD (Glucose-6-Phosphate Dehydrogenase)
102
HMP also makes _______, which is used by nucleated RBC’s during nucleic acid metabolism. 
Ribulose-5-phosphate (R-5-P)
103
Glutathione peroxidase converts RBC ___________ to water. 
Hydrogen peroxide (H2O2) 
104
If H2O2 builds up, it causes oxidation of Hgb to ______ (Which is unable to bind 02, thus excess levels cause hypoxia) 
MetHgb
Hgb Fe2+ (ferrous) —-> MetHgb Fe3+ (ferric)
105
EPO is produced in the ___________ in response to _________. 
Kidneys, hypoxia
106
Total of all erythrocytes in the body
Erythron
107
What is the normal adult M:E ratio? 
1.5:1 to 3.3:1
108
What is the average range for retics?
0.5 - 2.5 %
109
Which pathways are used to achieve ATP in RBC’s?
All pathways discussed
110
What is the normal absolute retic count range?
20 to 115 x 10^9/L
111
How do you calculate ARC? (Absolute reticulocyte count) 
Retic (%) x RBC count (x10^12/L)
Divided by
100
112
What does CFU-GEMM stand for?
Colony forming unit - Granulocyte, erythrocyte, megakaryocyte, monocyte
113
What does GM-CSF stand for?
Granulocyte macrophage colony stimulating factor 
