Week 7 Lec: RBC Structure, Metabolism, Destruction, Functions Flashcards
Term describing the dynamics of RBC production and destruction.
Erythrokinetics
Name given to the collection of all stages of erythrocytes throughout the body, developing precursor in the bm and the circulating RBC in peripheral blood.
Erythron
A hormone produced in the kidney in response to tissue hypoxia.
Erythropoietin (EPO)
A growth hormone for the production and proliferation of RBC.
Erythropoietin (EPO)
Where is EPO produced?
peritubular fibroblast in the kidney
Specific Action of EPO?
- Induces committed progenitor cells in the bone marrow to differentiate and proliferation into pronormoblast.
- Shortens the generation time of pronormoblast.
- Promotes the early release of reticulocytes to the peripheral blood.
Elevated EPO levels are observed in?
- Erythroid hyperplasia
- Polycythemia
- Hemorrhages
- Increased RBC destruction
- Testosterone
Decreased EPO level is seen in?
anemia
Mature RBCs should be?
soft and pliable
Mature RBC shape?
Biconcave disk (doughnut-shaped with a depressed area rather than a hole in the center)
Mature RBC size?
7 – 8 um in diameter
With _____ stain, central pallor (1/3) is seen.
Wright’s
Carries the oxygen to the cells of the body which is transported in a chemical combination with hemoglobin, a combination of heme (iron) and globin.
Mature RBC
The deficiency in the presence or metabolism of RBC results to decrease in?
hemoglobin and oxygen-carrying capacity
Mature RBC includes the assessment of?
– Color or Hemoglobin Content (Anisochromia)
– Size (Anisocytosis)
– Shape (Poikilocytosis)
– Structures and Inclusions
– Artifacts and Abnormal Distribution Patterns
Protein percentage?
52%
2 Types of Protein?
- Integral Protein
- Peripheral Protein
Integral Protein consists of?
Glycophorin A and Component A
Peripheral Protein consists of?
Spectrin and Actin
Lipid percentage?
40%
Internal Surface lipids?
- Phosphatidylethanolamine
- Phosphatidylinositol
- Phosphatidylserine
A ligand (binding) for phagocytosis of dead RBC.
Phosphatidylethanolamine
Important in complement regulatory proteins; deficiency can lead to hematologic problems such as PNH.
Phosphatidylinositol
Signals the death of RBC; important for clearance.
Phosphatidylserine
External Surface lipids?
- Phosphatidylcholine
- Glycolipid
- Sphingomyelin
Most abundant lipid that maintains the fluidity and structure of RBC membrane.
Phosphatidylcholine
It maintains the cholesterol content of RBC.
Lecithin cholesterol acyltransferase (LCAT)
Problems in Lecithin cholesterol acyltransferase (LCAT) cause?
acanthocytes
Carbohydrates percentage?
8%
Carbohydrates are supported in the RBC membrane by?
transmembrane protien
For determining the blood type.
Carbohydrates in RBC membrane
A antigen contains?
N-Acetyl-D-Galactosamine
B antigen contains?
D-Galactose
AB blood type contains?
N-Acetyl-D-Galactosamine and D-Galactose
O blood type contains?
none
Function of vertical interactions in the RBC membrane?
stabilizes the lipid bilayer membrane
Function of horizontal interactions in the RBC membrane?
support the structural integrity of RBC membrane
Vertical Anchorage?
- TRANSMEMBRANE Proteins
- INTEGRAL Proteins
- Traverses across the bilipid layer
- Band 3
- Glycophorins (A, B, C)
Horizontal/Lateral Anchorage?
- CYTOSKELETON proteins
- PERIPHERAL proteins
- Because the skeletal proteins do not penetrate the bilayer, they are also called peripheral proteins (spreads)
- α-spectrin and β-Spectrin
- Actin
- Protein 4.1
Membrane Proteins: Integral Proteins?
- Band 3
- Aquaporin
- Glycophorin A, B, and C
Anion transporter.
Band 3
Band 3 comprises how many percent of the total protein?
27%
Important for the prevention of surface loss.
Band 3
Water transporter.
Aquaporin
With Colton Antigen.
Aquaporin
Component of aquaporin that is also present in tubules of the kidney and can determine blood type.
Colton Antigen
Sialic acid transporter location of MN blood group antigen.
Glycophorin A
Glycophorin A percentage?
85% GP
Ss blood group antigen.
Glycophorin B
Glycophorin B percentage?
45% GP