Chapter 1- Red Blood Cell and Platelet Preservation Flashcards
Traditionally, the amount of whole blood in a unit was 450 ml +/- 10%, what is it more recently?
500 ml +/- 10%
with the increase of units of blood from 450 to 500 ml the volume of anticoagulant-preservative solution went from what to what?
63 ml to 70 ml
What is the max a 110 pound donor can donate?
525 ml whole blood
What is the total blood volume of most adults?
10 to 12 pints
how long does it takes a donor to replenish 1 pint of blood?
24 hours
How long does it take a donor to replace red blood cells?
1 to 2 months
How often can a donor donate?
every 8 weeks
Units of whole blood can be separated into how many components?
Three
What three components can whole blood be separated into?
packed RBCs, platelets, and plasma
Less whole blood has been used recently for platelets due to increased use of what?
Apheresis machines
Plasma can be converted via cryoprecipitation into what?
clotting factor concentrate rich in antihemophilic factor (factor VIII)
How long can a unit of whole blood be stored for?
21 to 42 days depending on additive
What are the three areas of RBC biology that are crucial for normal erythrocyte survival ans function?
- normal chemical composition and structure of the RBC membrane
- Hemoglobin structure and function
- RBC metabolism
Defects in any of the three RBC biology areas may result in RBCs surviving less than the normal_______ in circulation
120 days
What is the main lipid in the RBC membrane?
phospholipid
What is an integral membrane protein?
proteins that extend from the outer surface and span the entire membrane to the inner cytoplasmic side of the RBC
What is a peripheral membrane protein?
proteins beneath the lipid bilayer that are in the cytoplasmic surface forming the RBC cytoskeleton
To remain viable, normal RBCs must remain what?
flexible, deformable, and permeable
The loss of ATP levels lead to a decrease in phosphorylation of what and in turn loss of membrane what?
Spectrin
Deformability
When RBCs are ATP depleted, what happens to permeability of the RBC membrane?
Calcium and sodium are allowed to accumulate intracellularly and potassium and water are lost, this results in a dehydrated cell.
What pathways is RBC metabolism divided into?
anaerobic glycolytic pathway, and three ancillary pathways that serve to maintain structure and function
What are the three ancillary pathways of the RBC?
the pentose phosphate pathway, the methemoglobin reductase pathway, and the luebering-rapoport shunt
What percent of ATP does RBC glycolysis genertae?
90%
Approximately ____ ATP is generated by the pentose phosphate pathway?
10%
The luebering-rapoport shunt allows accumulation of what?
2,3-DPG
accumulation of 2,3-DPG in RBCs allows what?
it affects the affinity of hemoglobin for oxygen
What is hemoglobins primary function?
gas transport
The unloading of oxygen is accompanied by widening of a space between beta chains and the binding of _______ on a mole for mole basis, with the formation of anionic salt bridges between chains
2,3 DPG
What is the tense form of RBCs?
when oxygen has been unloaded and 2,3 DPG is bound, which has a lower affinity for oxygen
When hemoglobin loads oxygen and becomes oxyhemoglobin, the salt bridges are broken and beta chains are pulled together which expels 2,3 DPG, this is referred to as?
The relaxed form, which has a higher affinity for oxygen
The allosteric changes that occur as hemoglobin loads and unloads oxygen are referred to as?
respiratory movement
