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83 Cards in this Set

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What are RBCs aka?
erythrocytes
What do erythrocytes transport?
Oxygen
Diameter of erythrocytes?
about 8 micrometers or microns
What do RBCs lack? (3)
nucleus, organelles, and ribosomes
RBCs are mainly a pkg of what?
hemoglobin molecules
Structure of RBCs?
Flat, biconcave (indent on both sides), disc shape well-suited for it's function
-large surface area and thin
(which are advantageous for diffusion)

-flexible plasma membrane allows it to slide thru capillarys
2 general parts of hemoglobin?
1. globin

2. heme
Describe the globin part of hemoglobin?
protein made of four highly folded polypeptide chains
Describe the heme part of hemoglobin?
4 iron-containing, nonprotein groups
Hemoglobin has different proteins that change as we ?.
grow
Hemoglobin proteins of adult vs. fetus?
adult has alpha and beta groups...fetus has gamma and beta groups
What are the iron carriers of the heme part of hemoglobin?
1. transferrin (transport)

2. ferritin (storage)
Where is iron absorbed?
small intestine
When dying where are RBCs broken down/recycled?
in the spleen
When RBCs are broken down in the spleen what parts are recycled?
iron and globin
Since RBCs have no nucleus what can they not do?
no cellular division...RBCs in CIRCULATION cannot reproduce
What is the avg. lifespan of RBCs?
120 days
The site of final demise for old erythrocytes?
the spleen
What is erythropoiesis?
the production of new RBCs
Where does erythropoisesis take place?
in the marrow
In erythropoisesis, it takes 1 week for the stem cell in the bone marrow to become what?
a reticulocyte (immature RBC)
Reticulocyte is aka?
immature RBC
Reticulocytes mature over 24-48 hours to become what?
mature RBC
What percentage of the blood is normally reticulocytes?
about 1% (but may see increased conc. in disease states)
The number of erythrocytes normally remains what?
constant : highly regulated
What is the normal stimulus for erythropoiesis (RBC production)?
hypoxia (decreased oxygen concentration)
The process of erythropoiesis is controlled by what?
erythropoietin (EPO), a hormone produced by the kidneys
4 steps of erythropoiesis?
1. reduced oxygen carrying capacity stimulates the kidney

2. the kidney produces erythropoietin that stimulates the bone marrow

3. the developing erythrocytes in the bone marrow develop

4. leads to an increase in the oxygen carrying capacity of the circulating blood
4 general lab test to determine RBC disorders?
1. hemoglobin (content g/dL in blood)

2. hematocrit (vol. of cells in 100mL in blood, should be 99%RBC)

3. mean corpuscular volume (MCV): size of RBC

4. Reticulocyte count : immature RBC (indicates RBC rate of production)
What does normocytic mean?
normal size
What does microcytic mean?
small
What does macrocytic mean?
large
How many reticulocytes should be in the blood?
only about 1%
What is Anemia?
reduction below the normal capacity of blood to carry oxygen
Is anemia a disease?
No, it is not a disease. However, it is indicative of disease.
3 manifestations of anemia?
1. impaired oxygen transport, with resultant compensatory mechanisms

2. reducion in RBC indices and hemoglobin levels

3. signs and symptoms of pathology causing anemia
Name 4 types of anemias?
1. hemorrhagic (blood loss) anemia

2. hemolytic anemia

3. deficient RBC production anemias

4. chronic disease anemias
Describe hemorrhagic (blood loss) anemia?
1. anemia due to a LOSS of significant amounts of blood
(ex. wounds, mentstration, lowered hematocrit)

2. normochromic, normocytic

3. low hct, high reticulocyte count
Describe hemolytic anemia and name two types?
-due to DESTRUCTION of RBCs
-normochromic, normocytic, low hct, v. high reticulocyte count

1. sickle cell disease : RBCs fragile, vulnerable to hemolysis

2. Acquired hemolytic anemias: drugs, chemicals, toxins, venoms, infections (malaria)...ex. parasitic infections
-often immune-mediated (Abs to RBCs)
Name 4 types of DEFICIENT RBC production anemias?
1. iron-deficiency anemia

2. pernicious (B12 deficiency) anemia

3. folic acid anemia

4. aplastic anemia
Describe iron deficiency anemia?
-dietary deficiency of iron, loss of iron (bleeding), increased demand

-microcytic, hypochromic (smaller, decreased color)

-low ferritin
Describe pernicious anemia?
-due to inability to absorb adequate amounts of vitamin B12

-low absorption of B12 due to lack of "intrinsic factor"

-macrocytic, normochromic

-vegetarians (deprived of B12 from animal products)
Describe folic acid anemia?
-reqd for DNA synthesis and RBC maturation

-macrocytic, normochromic
Describe aplastic anemia?
-due to failure of bone marrow to make adequate numbers of RBCs (all blood cells affected, though)(not specific to RBC, because all blood cells come from bone marrow)

-may be seen in radiation, chemotherapy, cancer, etc.
Describe chronic disease anemias?
-COMPLICATION of chronic infections, inflammation, cancer

-normocytic, normochromic, decreased reticulocyte numbers
Theories of chronic disease anemias?
-actions of macrophages, lymphocytes in response to cell injury cause short life span, deficient RBC production in response to EPO, low serum iron

-possibly due to : Chronic renal failure, HIV, CA, rheumatoid arthritis
5 options for transfusion therapy?
1. whole blood

2. packed RBC

3. leukocyte poor RBC

4. washed RBC

5. frozen RBC
What is transfusion therapy used for?
if someone has less then 7 g/dL of hemoglobin (less than 1/2 the normal amount of hemoglobin)
Describe whole blood transfusion therapy?
when you replace the total blood volume
Describe packed RBC transfusion therapy?
centrifuge blood and remove 2/3rds of plasma
Describe leukocyte poor RBC transfusion therapy?
remove 99% of leukocytes, platelets, "buffy coat" removed, so increased [RBC]
Describe washed RBC transfusion therapy?
washed in normal saline, centrifuge and remove "junk" and plasma
Describe frozen RBC as it relates to transfusion therapy?
-good in massive blood drives for storage, mix RBC with glycerol to prevent from dying (when used, needs to be washed and centrifuged)
-will keep up to 10 years
What is autologous blood donation?
involves your own blood
What is predeposit autologous donation?
when you donate your own blood before surgery
What is hemodilution as it relates to blood donations?
phlebotomy before surgery
What is intraoperative salvage (blood donation)?
middle of operation (blood is continously circulated from patient thru automated system and back into pt)
3 things donor blood is tested for?
1. ABO surface antigens (to determine blood type)

2. Rh types (+ or -)

3. infection risks
How is blood type compatibility determined?
by antigens (A or B proteins, on blood cells)
Speed of ABO incompatibility?
rapid
Describe type A blood?
Type A (AA or AO)
-have antibodies for B antigen
Describe type B blood?
Type B (BB or BO)
-abs for A antigen
Describe type AB blood?
-no serum antibdies
-A and B both look normal
Type AB is the univeral what?
recipient
Describe Type O blood?
OO
-no surface antigens
-produce antibodies to both A and B
-universal donor
The speed of Rh incompatibilities?
slower to develop then ABO incompatibility
Different gene pairs involved in Rh compatibility?
C and c
D and d
E and e
...only one that matter is D
...if you have D you are positive, if not then negative
10 signs and symptoms of transfusion rxns (ABO or Rh incompatibility)?
1. heat along vein being infused

2. flushing of face

3. urticaria (skin eruption, often hives)

4. headache

5. pain in lumbar area

6. chills, fever

7. nausea, vomiting

8. tachycardia

9. hypotension (low bp)

10. Dyspnea (labored breathing)

(tachycardia and hypotension can cause death)
What is polycythemia?
excess circulating RBCs
Polycythemia produces an elevated what?
hematocrit (>50%)
What is absolute polycythemia?
elevated hematocrit due to increased total RBC mass
Name the two types of absolute polycythemia?
1. primary polycythemia

2. 2ndary polycythemia
Primary polycythemia is aka?
polycythemia vera
Describe primary polycythemia?
proliferative disease of pluripotent cells in bone marrow

-a type of absolute polycythemia
Describe 2ndary polycythemia?
-a type of absolute polycythemia

-EPO induced adaptive (appropriate) mechanism to improve the oxygen carrying capacity of the blood
What is relative polycythemia?
elevated hematocrit due to loss of plasma volume

(ex. dehydration due to heavy sweating, diarrhea)
4 signs and symtpoms of polycythemia?
1. increased blood viscosity

2. htn

3. venous stasis

4. thromboembolism
What is the increased blood viscosity in polycythemia due to?
CO and blood flow reduced
Describe HTN as it relates to polycythemia?
it is common because the heart tries to overcome the increased viscosity by increasing the blood pressure
Describe 4 symptoms that may result from the HTN in polycythemia?
1. headache

2. inability to concentrate

3. vision

4. hearing trouble from decreased cerebral blood flow
Describe the symptom of venous stasis in polycythemia?
dusky redness (even cyanosis (blue appearance)) of lips, fingernails, and mucous membranes
Describe the symptom of thromboembolism of polycythemia?
blood stasis
Tx for polycythemia?
for primary you reduce viscosity via

1. phlebotomy to draw out blood and decrease RBC volume

2. suppress bone marrow fcn via chemotherapy reduces wbc and platelet counts