Unit 2 - Erythrocytes (Chapters 5-7)
We also commonly think of partial pressures as
"dissolved" molecules
MCHC units
%
MCV formula
(Hct % X 10) / RBC Count = fL
MCH formula
(Hgb X 10) / RBC Count = pg
MCHC formula
(Hgb x 100) / Hct % = % Hct
Reticulocyte (polychromatophilic erythrocyte)
-->Anuclear -Part of this stage takes place in bone marrow and part takes place in the circulating blood -->Cells show reticular appearance due to residual RNA in the cytoplasm when stained with supravital stain such as new methylene blue. -->On Wright's stain, red shows show polychromatophilia
Methemoglobin
-A hemoglobin variant in which the iron is oxidized to the ferric (Fe3+ ) state -In this form, Hgb is incapable of combining with oxygen -This form is constantly being produced, however, natural reducing systems in red blood cells continually converts ferric iron to the ferrous state -Iron in the ferrous (Fe +2) state is capable of transporting oxygen -production can result from environmental factors such as exposure to oxidant chemicals -Infants are more susceptible to "this" because Hgb F is more easily converted to "this" than is adult Hgb A
Hemoglobin A
-Dominant form of hemoglobin in the normal adult (95% to 97%) -Composed of 2 alpha chains and 2 beta chains
Orthochromatic normoblast (metarubricyte)
-Extended nucleus --"Nucleated" RBC -Chromatin is tightly clumped- pyknotic -Cytoplasm is acidophilic- pink - showing large quantities of hemoglobin -2-3 mitotic divisions occur between rubriblast and metarubricyte stage -After this stage, cell division cannot take place
Carboxyhemoglobin
-Formed by the reaction of hemoglobin with CO gas -Affinity for Hgb for CO is 210 times greater than its affinity for oxygen -Resulting COHgb is extremely stable -In this form, hemoglobin is useless for oxygen transport -Normal is up to 0.5% -20-30% = symptoms of dizziness, nausea, muscle weakness and headache -Levels of 50% and greater are rapidly fatal
Intravascular Catabolism of Erythrocytes process
-Hemoglobin is released directly into the bloodstream where it is bound to haptoglobin. -Complex is too large to be freely filtered by the kidneys so the iron is not lost in the urine -Iron removed from haptoglobin in liver and recycled -This accounts for the reduced level of haptoglobin present in patients with intravascular hemolysis
Sulfhemoglobin
-Hgb variant that contains sulfur -Not capable of carrying oxygen -Can precipitate in red blood cells to form Heinz bodies -May be formed as a result of certain drugs such as phenacetin or with some bacteremia involving -Clostridium welchii
Resulting components of extravascular catabolism of erythrocytes
-Iron -Protoporphyrin -Globin
Other cytoplasm functions in RBCs
-Keep hemoglobin in the ferrous 2+ state -Sodium/Potassium pump -Maintain enzymes and globulin in the active state -Preserve cell membrane integrity
Glycosylated Hemoglobin (Hemoglobin A1) reference ranges
-Normal, non-diabetic individuals have 3-6% glycated hemoglobin -Diabetic patients (IDDM- NIDDM) have 6-12% or higher values -Test is a measure of long term plasma glucose levels***
What is true about intravascular destruction of erythrocytes?
-accounts for less than 10% of erythrocyte breakdown -hemoglobin is released directly into blood -alpha and beta dimers are bound to haptoglobin
Hemoglobin A2
-also found in small quantities (2% to 3%) 2 alpha + 2 delta
Basic substances needed for normal erythrocyte and hemoglobin production are...
-amino acids (proteins) -iron -vitamin B12 -vitamin B6 -folic acid (a member of the vitamin B2 complex) -trace minerals cobalt and nickel
Chloride Shift
-bicarb diffuses into plasma in exchange for chloride (process is reversed in the lungs) -keeps reaction proceeding; exchanges HCO3 for Cl- (H+ binds to hemoglobin)
Mature erythrocyte
-biconcave disc -anuclear -pink cytoplasm -normal adult values: -->Male: 4.5-5.9 x 10^6/uL -->Female: 4.5-5.1 x 10^6/uL
Secondary or absolute polycythemia
-due to an increased production of erythropoietin -->Triggered by tissue hypoxia -->Due to defective hemoglobin, chronic lung disease, smoking, or renal neoplasms
Mean Corpuscular Hemoglobin Concentration (MCHC)
-expresses the average concentration of hemoglobin per unit volume of erythrocytes -also defined as the ratio of the weight of hemoglobin to the volume of erythrocytes -hemoglobin content relates to the amount of color in the RBC when viewed under microscope; good color descriptor =Result is expressed in % -normal value of MCHC is 32% to 36%. -Red cells that produce this in the normal range are referred to as normochromic -less than 32% indicates hypochromic red cells -greater than 36% is referred to as hyperchromic red cells
Mean Corpuscular Volume (MCV)
-expresses the average volume of an erythrocyte -good size descriptor (under Wright stained blood film) =femtoliters (fL) -reference value of MCV is 80 to 96 fL. -Red cells in the normal range are called normocytic -Red cells which have a ______< 80 fl are microcytic -Red cells which have a ______ > 96 fl are macrocytic
Mean Corpuscular Hemoglobin (MCH)
-expresses the average weight (content) of hemoglobin in an average erythrocyte. It is directly proportional to the amount of hemoglobin and the size of the erythrocyte =picograms (pg) -reference value of MCH is 27 to 32 pg. -less than 27 pg is seen in microcytic anemia -greater than 32 pg is seen in macrocytic anemia or spherocytosis -not utilized often in interpretations
In order to combine with oxygen, the iron of the heme group must be in what state?
-ferrous (Fe2+) oxidation state to support oxygen and other gases' binding and transport -it temporarily switches to ferric during the time oxygen is bound -initial oxidation to the ferric (Fe3+) state without oxygen converts hemoglobin into "hemiglobin" or methemoglobin, which cannot bind oxygen
Embden-Meyerhof pathway
-glycolytic pathway another name for glycolysis; how the RBC gets energy
Cytoplasm Enzymes Characteristics of RBCs
-have long-lived enzymes which drive cellular metabolism -are produced during the early phase of cell development and must be present in large enough quantity to provide all the energy requirements for the life of the cell
Polycythemia
-increase concentration of erythrocytes (erythrocytosis) in the circulation above the normal for sex and age
Relative polycythemia
-increase in erythrocytes that is NOT due to increased erythropoietin -->Decreased plasma volume- dehydration, diarrhea or burns
Fetal hemoglobin- Hgb F reference ranges
-may be present at levels of up to 2% of the total hemoglobin -Some adults retain up to 15 to 30% of this in a condition known as "hereditary persistence of Hgb F"
hemoglobin exhibits cooperative binding which means
-one binding makes the other bindings more likely -once one molecule of oxygen binds the hemoglobin molecule changes, and the other molecules want to bind this as well
Glycosylated Hemoglobin (Hemoglobin A1)
-subfraction of normal hemoglobin A -subfraction can be termed glycosylated hemoglobin and includes the separate hemoglobin fractions A1a, A1b, and A1c -Formed when a glucose molecule binds with the terminal amino acid of the beta chain -Changes takes place in a hyperglycemic person
Fetal hemoglobin- Hgb F
-the predominant hemoglobin variety in the fetus and the newborn -has two alpha and two gamma chains -appears by the fifth week of gestation and persists for several months after birth
Reticulocytes represent approximately _________________ of the circulating erythrocytes (normal range)
0.5% to 1.5% (count is expressed as a percentage of total erythrocytes)
Once young reticulocytes enter the circulating blood, they remain in the reticulocyte stage for an average of _________
1 day
A hemoglobin molecule is composed of...
1) 4 heme groups 2) 4 polypeptide chains -->2 alpha chains -->2 beta chains
How is carbon dioxide removed by the body?
1) CO2 diffuses into the erythrocytes, is catalyzed by the enzyme carbonic anhydrase, and is transformed into carbonic acid. Includes chloride shift. (75%) 2) Direct binding to deoxygenated hemoglobin (25%) 3) Physical dissolving of CO2 into plasma water
Variant forms of normal hemoglobin
1) Carboxyhemoglobin 2) Sulfhemoglobin 3) Methemoglobin
Catabolism of Erythrocytes---- as an erythrocyte ages, what processes occur?
1) The membrane becomes less flexible. 2) The concentration of cellular hemoglobin increases. 3) Enzyme activity, particularly glycolysis, diminishes
In the clinical laboratory, the red blood cell indices serve as
1) a quality control check on patient data 2) a means to differentiate and describe anemias
As the erythrocyte ages....
1) the membrane becomes less flexible with loss of cell membrane 2) cellular hemoglobin increases 3) enzyme activity, particularly glycolyis, decreases
The upper limit of the reference range of hemoglobin in an adult male is...
14-18.0 g/dL
Bone marrow reticulocytes have an average maturation period of _______________
2.5 days
The reticulocyte normal range in infants is...
2.5% to 6.5% (but this value falls to the adult range by the end of the second week of life)
MCH reference or normal range
27-32 pg
MCHC reference or normal range
32%-36%
How many molecules of oxygen can one hemoglobin molecule hold?
4
The number of heme groups in a hemoglobin molecule is
4
Once the stem cell differentiates into the erythroid cell line, a cell matures through the nucleated cell stages in...
4 or 5 days
MCV reference or normal range
80-96 fL
MCH elevated
<27 pg is seen in microcytic anemia
MCHC low
<32% indicates hypochromic red cells
MCV low
<80 fL = microcytic
RPI
= (corrected reticulocyte count in %) / (maturation time in days)
Reticulocyte production index
= measures erythropoietic activity when stress reticulocytes are present
Corrected reticulocyte count
= retic count X (patient's HCT (%) / normal age/sex specific HCT (%))
MCH low
>32 pg is seen in macrocytic anemia or spherocytosis
MCHC elevated
>36% is referred to as hyperchromic red cells
MCV elevated
>96 fL = macrocytic
Which of the following hemoglobin types is the major type present in a normal adult?
A
megaloblastic maturation
A defect in maturation can be seen in certain anemias, such as vitamin B12 or folate deficiencies
Erythrocytic catabolism produces the disassembling of hemoglobin followed by...
A) iron transported in the plasma by transferrin B) globin catabolized in the liver to amino acids and then entering the amino acid pool C) bilirubin formed form opened porphyrin ring and carried by plasma albumin to the liver, conjugated, and excreted in the bile
Intravascular Catabolism of Erythrocytes (Percent Destroyed in this manner)
Accounts for less than 10% of erythrocytic destruction
carbonic anhydrase
An enzyme that catalyzes the formation of carbonic acid (H2CO3) from carbon dioxide and water
Extravascular Catabolism of Erythrocytes (Percent Destroyed in this Manner)
Approximately 90% of red cells
The sickle gene may commonly occur with hemoglobin ______
Bart
N:C ratio 4:1 --Nucleus --Chromatin becomes more clumped Nucleoli are not visible!!!!!!!!!!!!!!!! Cytoplasm continues to be basophilic
Basophilic normoblast (prorubricyte)
75% of carbon dioxide is removed by...
CO2 diffuses into the erythrocytes, is catalyzed by the enzyme carbonic anhydrase, and is transformed into carbonic acid. H2O + CO2 --------- H2CO3 The hydrogen ion of carbonic acid is accepted by the alkaline deoxyhemoglobin, and the bicarbonate ion diffuses back into the plasma. H2CO3 ----------- H+ + HCO3 -
About 25% of carbon dioxide is removed by...
Direct binding to deoxygenated hemoglobin
Decrease in oxygen within a tissue produces increase in...
EPO production
The major hemoglobin synthesized in the second semester fetus is
F
Ferrous iron
Fe (+2)
Iron reduced state
Fe (+2) -capable of transporting oxygen -ferrous
Ferric iron
Fe (+3) "icky"
Iron oxidized state
Fe (+3) -incapable of combining with oxygen -ferric iron -think of methemoglobin
Most of iron entering cell is committed to __________________________________________ and proceeds to the mitochondrion where it is inserted into the protoporphyrin ring to form ______________
Hgb synthesis; heme
hemoglobin
In the mature cell, the respiratory protein that performs the function of oxygen-carbon dioxide transport; made up of... -4 heme groups -4 polypeptide chains -->2 alpha chains -->2 beta chains
This is removed from haptoglobin in liver and recycled (intravascular hemolysis)
Iron
The type of hemoglobin that is detectable with the _____________________ is hemoglobin F
Keihauer-Betke test
describe the oxygen dissociation curve in general terms
Left shift: higher O2 affinity Right shift: lower O2 affinity
Hematocrit normal range
Males: 41.4%-50.4% Females: 36-45%
Basophilic normoblast (prorubricyte)
N:C ratio 4:1 --Nucleus --Chromatin becomes more clumped Nucleoli are not visible!!! Cytoplasm continues to be basophilic
Polychromatophilic normoblast (rubricyte)
N:C ratio is 1:1 Chromatin is increasingly clumped Pink coloration is visible in the cytoplasm due to hemoglobin production!!! Overall purplish color due to mixing
Hemoglobin Reference Ranges
Normal Adult Values Male 14.0-18.0 g/dL Female 12.0-16.0 g/dL -Newborns are higher
-Extended nucleus --"Nucleated" RBC -Chromatin is tightly clumped- pyknotic -Cytoplasm is acidophilic- pink - showing large quantities of hemoglobin -2-3 mitotic divisions occur between rubriblast and metarubricyte stage -After this stage, cell division cannot take place
Orthochromatic normoblast (metarubricyte)
Rubricyte is also called a...
Polychromatophilic normoblast
N:C ratio is 1:1 Chromatin is increasingly clumped Pink coloration is visible in the cytoplasm due to hemoglobin production!!! Overall purplish color due to mixing
Polychromatophilic normoblast (rubricyte)
1) N:C ratio is 4:1 2) Large round nucleus -0-2 nucleoli -Dark appearing -Fine chromatin 3) Cytoplasm is blue- basophilic -RNA activity needed to make proteins for the globin portion of hemoglobin -No granules
Pronormoblast or rubriblast
amino acids (proteins), iron, vitamin B12, vitamin B6, folic acid (a member of the vitamin B2 complex), trace minerals cobalt and nickel
The basic substances needed for normal erythrocyte and hemoglobin production are:
Rubriblast
The most immature stage of red blood cell development -look for nucleoli! aka pronormoblast
haptoglobin
This protein binds to toxic free hemoglobin in the bloodstream to protect tissues (kidney) from damage
Heme pigment in hemoglobin
Transport of oxygen to the tissues and transport of carbon dioxide from the tissues is accomplished by this which is synthesized as the erythrocyte matures
Extravascular Catabolism of Erythrocytes
When an erythrocyte is phagocytized and digested by the macrophages of the mononuclear phagocytic system, the hemoglobin molecule is disassembled
A mature erythrocyte is...
a biconcave disc with a central pallor that occupies the middle one third of the cell
Erythropoietin is
a glycoprotein growth factor produced primarily by the kidneys
If normal adult (A1) and fetal hemoglobin F are compared, fetal hemoglobin has ___________________ for oxygen
a greater affinity
a biconcave disc with a central pallor that occupies the middle one third of the cell
a mature erythrocyte
In cases of chronic carboxyhemoglobin exposure, the patient's oxygen dissociation curve would exhibit...
a shift to the left -a decrease in temperature
If a young male was preparing for Olympic competition and had his blood drawn for the measurement of oxygen dissociation, his results would demonstrate....
a shift to the right -decreased O2 affinity -increased O2 release -increased CO2 increased H+ (decreased pH)
Changes in amino acid sequence results in an ______________________ hemoglobin molecule
abnormal
In an __________________________________, our oxygen diassociation curve would be a "shift to the right." This leads to lower oxygen affinity, and a greater need to release oxygen to the tissues. This would also lead to an increase in ____________________
acidic environment; 2,3 DPG activity
pH, temperature and the level of 2, 3-DPG....
all affect the association (binding) of oxygen to hemoglobin in the lungs and dissociation (release) of oxygen at tissue
Most defects in the hemoglobin molecule are related to
amino acid substitutions and diminished production of one of the polypeptide chains
Exact sequence of _________________________ in the protein chains is critical for functional hemoglobin
amino acids
The exact sequence of ______________________ in the protein chains is critical for functional hemoglobin
amino acids
Abnormal erythropoiesis and anemia can result from deficiencies of...
amino acids (proteins), iron, vitamin B12, vitamin B6, folic acid (a member of the vitamin B2 complex), trace minerals cobalt and nickel
Life span of an erythrocyte
an average of 120 days -->soft and pliable cell moves with ease through the tissue capillaries and splenic circulation
If there is no RBC pathology (normal cell size, normal RBC HGB concentraion, no abnormal forms), a discrepancy in the rule of 3 suggests _______________ in one or more of the measurands
analytic error
Recombinant erythropoietin is available for patients with...
anemia of chronic renal failure
Probrubricyte is also known as a...
basophilic normoblast
Rule of three
because normal RBCs are biconcave discs with a uniform quantity of hemoglobin (HGB) in each cell, there is a fairly constant numeric relationship involving RBC, HGB, and hematocrit (HCT) -HCT = HGB X 3 -HGB = RBC X 3
So again, with carbon dioxide transport, a small percent (5%) will stay dissolved in the plasma, about 25% will directly bind to another site on the molecule, and nearly 75% will diffuse and be converted to carbonic acid and then ___________________________.
bicarbonate
Cytoplasm is initially this color as it is basophilic
blue
As oxygen diffuses out, ________________________ diffuses in due to partial pressure of oxygen higher in blood than tissues; ________________________ higher in tissue than blood.
carbon dioxide; carbon dioxide
After a man was found unconscious in his garage with the car motor running, he was transported to the emergency department. When blood was drawn for a complete blood count, the plasma was noted to be bright red. What kind of variant hemoglobin should be suspected?
carboxyhemoglobin
The bicarbonate molecule (HCO-3) will diffuse out of the RBC, and a chloride molecule will enter to maintain electron neutrality, known as the ___________________________
chloride shift
Hemoglobin is the respiratory pigment that gives an erythrocyte its characteristic ___________________
color
Kleihauer-Betke Procedure
commonly used to determine the amount of fetal blood that has mixed with maternal blood following delivery -Acid denaturation of hemoglobin to determine the amount of fetal hemoglobin in maternal circulation -Fetal hemoglobin resists acid denaturation whereas adult hemoglobin is denatured
allosteric inhibition
conformation is altered; substrate no longer binds -this is how hemoglobin "knows" to not bind oxygen and/or release bound molecules -this is a result of CO2 (H+) in blood
As the erythrocyte ages...
cytoplasmic enzymes are catabolized, leading to increased membrane rigidity (density), phagocytosis, and destruction
Increased amounts of 2,3-DPG ______________________________ of the hemoglobin molecule
decrease the oxygen affinity
A decrease in pH (increase in H+), increase in CO2, or an increase in temperature...
decreases the affinity of hemoglobin for oxygen (shift right)
Cytoplasmic basophilia _________________ as the erythrocyte matures....
decreases! -->Ribosome (basophilic because of RNA content, i.e. stains blue) appears first -->Ribosome synthesizes Hemoglobin (acidophilic, i.e. stains pink) -->As the haemoglobin content approaches the desired levels the number of ribosomes decreases. -->As erythropoiesis progressess the cytoplasm changes from deep blue (mainly ribosomes) in basophilic normoblast to polychromatophilic (ribosomes and haemoglobin) in polychromatophilic normoblast and resembling that of a erythrocyte (mainly haemoglobin) in orthochromatophilic normoblast
Abnormal erythropoiesis and anemia can result from...
deficiencies of any of these necessary substances (amino acids, iron, B12, B6, B2, folic acid, cobalt, nickel).
A method for the preliminary identification (screening method) of abnormal hemoglobin is _____________________________.
electrophoresis
After a molecule of hemoglobin gains the first two oxygen molecules, the molecule
expels 2,3-DPG
MCV units
femtoliters (fL)
If globin synthesis is insufficient in a person, iron accumulates in the cell as _________________ aggregates
ferritin
polychromatophilia
fine, evenly distributed basophilic (blue) granules that impart a blue color to WRight-stained erythrocytes -stain bluish and are large immature RBCs -characteristic of reticulocytes
Pronormoblast
first morphologically-recognized cell in the red cell series -look for nucleoli! -aka rubriblast
_____________ molecules of oxygen can be carried on each hemoglobin molecule
four
The correct molecular composition of hemoglobin is
four heme groups; two alpha and two beta globin chains
Rule of 3 applies only to ____________________________________
fresh normal human specimens (not to commercial control materials)
Hemoglobin A1 aka...
glycosylated hemoglobin (includes A1a, A1b, and A1c)
Major portions of hemoglobin are ___________ and _____________
heme; globin
Chemical composition: 4 heme groups 4 polypeptide chains -2 alpha chains -2 beta chains
hemoglobin
The alkaline denaturation test detects the presence of...
hemoglobin F
The dark staining granules in the red blood cells when a bone marrow smear stained with Prussian Blue stain is examined represent a defect of
hemoglobin synthesis
deoxyhemoglobin
hemoglobin that does not have any oxygen molecules attached to it -2,3-DPG combines with the beta chains of deoxyhemoglobin and diminishes the molecule's affinity for oxygen
As the result of intravascular destruction, _________________________ is released directly into the bloodstream and undergoes dissociation into alpha and beta dimers, which are quickly bound to the plasma globulin ____________________________.
hemoglobin; haptoglobin
Left shift
higher O2 affinity; decrease O2 release
A characteristic of methemoglobin is that it is...
incapable of combining with oxygen
An increase in pH (decrease in H+), decreased CO2, increased CO, or a decrease in temperature...
increases the affinity of hemoglobin for oxygen (shift left)
The child's medical history and appearance of dense, dark-staining particles in some of the red blood cells on a peripheral blood smear suggest a diagnosis of...
ingestion of lead
If a female patient is diagnosed with anemia and her follow-up assays indicate a blood serum results of increased bilirubin and decreased haptoglobin with hemosiderin in her urinary sediment, what is the most probably diagnosis?
intravascular catabolism
Decreased haptoglobin levels likely suggest...
intravascular hemolysis or catabolism of RBCs
Major function of hemoglobin.......
is the transport of oxygen to the tissues
Heme is synthesized predominantly in the...
liver and red bone marrow
Right shift
lower O2 affinity; increase O2 release
Anemic or chronic renal failure patients usually have _______________________________ because they can't produce enough erythropoietin (target hemoglobin level usually 11-12 g/dl for
lower hemoglobin levels
Survives in circulation for 120 days
mature erythrocyte
Male: 4.5-5.9 x 10^6/uL Female: 4.5-5.1 x 10^6/uL
mature erythrocyte normal values -newborns have higher levels initially due to initial hypoxia
Orthochromatic normoblast is also called a...
metarubricyte
The initial condensation reaction in the synthesis of porphyrin preceding heme formation takes place in the ____________ and requires __________________
mitochondria; vitamin B12
Newborns typically have
on average higher hemoglobin levels to compensate for initially systemic hypoxia, which leads to a decrease need as age
metarubricyte is also called a....
orthochromatic normoblast
When a hemoglobin molecule just leaves lungs it is fully saturated and more inclined to give up __________________ in response to tissue needs.
oxygen
About 5% of the carbon dioxide is removed by...
physical dissolving of CO2 into plasma water
MCH units
picograms (pg)
Cytoplasm becomes acidophilic and turns this color as more hemoglobin is present
pink
Reticulocyte is also known as...
polychromatophilic erythrocyte
Basophilic normoblast is also known as...
probrubricyte
Hemoglobin is synthesized in _________________________ before the nucleus is extruded
red blood cells
Erthrocytes mature in
red bone marrow
Synthesis of hemoglobin occurs in most body cells with the exception of mature erythrocytes. The primary sites are ____________________ and _______________________
red marrow; liver
Polychromatophilic erythrocyte is also known as...
reticulocyte
Erythropoietin produces an increase in the production of several types of...
ribonucleic acid (RNA) followed by an increase in deoxyribonucleic acid (DNA) activity and protein synthesis
Polychromatophilic normoblast is also called a....
rubricyte
In normal infants, fetal hemoglobin (hemoglobin F) persists until...
several months after birth
If the reticulocyte count is elevated, it would indicate....
shorter than expected red cell survival
Older cells that are no longer able to pass freely through the microcirculation are taken by the _______________ via _________________________
spleen; phagocytosis
Cell is soft and pliable and can more with ease through tissue capillaries and in the ____________________________
splenic microcirculation
Heme group is...
split and converted in the liver to bilirubin (extravascular)
Oxyhemoglobin is a _____________ than deoxyhemoglobin
stronger acid
Heinz bodies are associated with
sulfhemoglobin
Biconcave maximum provides
surface area and greatest flexibility
Glycosylated hemoglobin is a stable hemoglobin and is structurally the same as hemoglobin A except for...
the addition of a carbohydrate group at the terminal valine of the beta chain.
An erythrocyte has a limited ability to metabolize fatty acids and amino acids and lacks mitochondria for oxidative metabolism, thus energy comes almost exclusively from....
the breakdown of glucose
oxyhemoglobin
the bright red hemoglobin that is a combination of hemoglobin and oxygen from the lungs
Globin is catabolized in...
the liver into its constituent amino acids and enters the circulating amino acid pool (extravascular)
The final steps in heme synthesis, including the formation of protoporphyrin, take place in...
the mitochondria
Iron is transported in...
the plasma by transferrin to be recycled by the red bone marrow in the manufacture of new hemoglobin (extravascular)
Erythropoiesis
the process of erythrocyte production -->encompasses differentiation from the hematopoietic stem cell (HSC) through the mature erythrocyte
The reticulocyte count procedure is frequently performed in the clinical laboratory as an indicator of
the rate of erythrocyte production
Hemoglobin is...
the respiratory pigment or protein in red blood cells
2, 3- diphosphoglycerate (2,3 DPG)
this enzyme helps "move" the oxygen off of the hemoglobin molecule to the tissues
Blood levels of erythropoietin are inversely related to...
tissue oxygenation
Iron needed for heme synthesis is carried to the site of utilization by the transport protein _____________________
transferrin
The protein responsible for the transport of iron in hemoglobin synthesis is...
transferrin
Hemoglobin A consists of...
two alpha and two beta chains
Normal adult hemoglobin has
two alpha and two beta chains
These polypeptide chains are called globin chains. Normal adult hemoglobin molecules have
two alpha and two beta chains
Hemoglobin A2 consists of
two alpha and two delta chains
Hemoglobin F consists of
two alpha and two gamma chains
Erythrocyte indices or red blood cell indices
used to mathematically define cell size and the concentration of hemoglobin within the cell Includes: Mean corpuscular volume (MCV) Mean corpuscular hemoglobin (MCH) Mean corpuscular hemoglobin concentration (MCHC)
Embryonic hemoglobin consists of
zeta chains and either epsilon or gamma chains
