RBC Flashcards
Mature RBC size
6-8 micron
less stable than those of mature cells
reticulocytes
the skeletal system for living cell
tubulin
responsible for contraction and relaxation of the membrane
actin
Mature Red Blood Cell Membrane
Soft and pliable
Biconcave shape
Consists of a membrane skeleton
protein lattice and lipid bilayer
Outer layer of membrane lipids
- phosphatidyl choline
- sphingomyelin
Inner layer of membrane lipids
- phosphatidyl serine
- phosphatidyl ethanolamine
Membrane proteins
- integral protein
- peripheral protein
Integral protein
BAG
- Band 3
- Aquaporin
- Glycophorin
Peripheral protein
o Actin
o Protein4.1
o Pallidin(band4.2)
o Ankyrin
o Adducin
o Tropomycin
o Tropomodulin
Anion transport
BAnd 3
Interaction with ankyrin and protein
4.2, secondarily through binding to
protein4.1
Band 3
Imparts a negative charge to the cell
Glycophorin
Exchanges bicarbonate for
chloride
Band 3
Selective pores for water transport
Aquaporin
Flexible,rod-likemolecule
spectrin
two subunit of spectrin
Alpha and beta spectrin
responsible for the shape of RBC
spectrin, ankyrin, actin
Attachment for ankyrin near C terminus
beta spectrin
Short, uniform filaments
actin
Length of actin is modulated by
tropomyosin/tropomodulin
Stabilizes actin-spectrin interactions
Protein 4.1
Also stabilzes interaction of spectrin with actin
* Influenced by calmodulin
Adducin
Promotes spectrin-actin interactions
ankyrin
Interacts with band 3 and spectrin to achieve linkage
between bilayer and skeleton
ankyrin
During pressure upon RBC, spectrin molecules undergo
reversible change in conformation: some uncoiled and
extended, others compressed and folded.
membrane deformability
Cytoplasmic contents of RBCs include
potassium ions,
sodium ions, glucose, intermediate products of
glycolysis and enzymes
Major source of the essential cellular energy
Embden-Meyerhof Pathway
Embden-Meyerhof Pathway end product
pyruvate and lactate
Embden meyerhof pathway glycolysis
Anaerobic glycolysis
percentage of glycolysis occurs in EMP pathway
90%
How EMP form ATP
glucose > lactic acid > form 2 ATP
Oxidative Pathway also known as
Hexose monophosphate shunt
Pentose phosphate pathway
what is the enzyme involved in hexose monophosphate shunt?
G6PD
Percentage of glycolysis occurs in hexose monophosphate shunt
10%
How reduced glutathione form
Convert NADP to NADPH then NADPH will
convert to reduced glutathione
end product of Hexose monophosphate shunt
production of reduced glutathione
Depends on Embden-Meyerhof pathway for the reduced
pyridine nucleotides that keeps hgb in a reduced state
methemoglobin reductase pathway
function of methemoglobin reductase pathway
maintains hemoglobin iron in the ferrous state and this will then convert methemoglobin back to normal hemoglobin using methemoglobin reductase enzyme
Important in the oxygen carrying capacity of
RBCs
Leubering-Rapoport Pathway
regulates oxygen affinity of hemoglobin
Leubering-Rapoport Pathway
Leubering-Rapoport pathway will generate ______ to regulate the affinity in
hemoglobin to oxygen.
2,3DPG (2,3 – Diphosphoglycerate)
low 2,3 DPG therefore high hemoglobin affinity
shift to the left
high 2,3 DPG therefore low hemoglobin affinity
shift to the right
prevents denaturation of globin of the hemoglobin molecules by oxidation
oxidative pathway
Term describing the dynamic of RBC production
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
- Elevated EPO levels are observed in:
Erythroid hyperplasia
Polycythemia
Hemorrhages
Inc RBC destruction
– loss of a portion of the erythrocytes
membrane, accompanied by loss of cellular contents
including hemoglobin
Fragmentation
passing of water into the red cell as to
ultimately burst it
. Osmotic lysis
ingestion of whole red cells by
circulating monocytes or neutrophil or by fixed
macrophages of the mononuclear phagocyte system
Erythrophagocytosis
complement has the
ability to attach itself to the cells and induce lysis.
Complement induced cytolysis
Lysis of erythrocytes which occurs within the
circulation through the classic pathway
Intravascular hemolysis
major free
hemoglobin transport protein
Haptoglobin
hemoglobin in plasma will bind to
- haptoglobin
- hemoglobinemia/hemoglobinuria
- renal tubular
recycled into amino acids for protein synthesis
globin
What will bind to transferrin that will be transported to bm
iron
causes INTRAVASCULAR HEMOLYSIS
ABO mismatched blood transfusion
o Cold agglutinin disease (CAD)
o Paroxysmal cold hemoglobinuria
Burns
Snake bites
o Bacterial – C.perfringens sepsis
o Parasitic infection
o Mechanical heart valvles
o Paroxysmal nocturnal hemoglobinuria
causes EXTRAVASCULAR HEMOLYSIS
o Bacterial/Viral infections
o Drug induced
o Autoimmune
o Microangiopathic Hemolytic Anemia
o Hemoglobinopathies
o Membrane defects
o Metabolic defects
linkage of lipid bilayer to underlying membrane skeleton
band 3
support all the content and structural integrity of the RBC
horizontal interaction
support the internal and external of RBC (all the content of RBC)
vertical interaction
carries MN and gerbich blood group antigen
Glycophorin A
important for P. falciparum invasion and development in RBC
Glycophorin C, glycophorin A
It is very rich in sialic acid which will need of RBC to become hydrophilic to enable them to circulate without adhering to other cells
Glycophorin
Aquaporin also known as
water transporter
Allows RBC to remain in osmotic equilibrium with extracellular fluid
Aquaporin
binding site for actin filaments and protein 4.1
At N terminus
augmented by protein 4.2
ankyrin
deformability is an important property of red cell function influence by:
- cell shape
- cytoplasmic viscosity
- membrane deformability and stability
yellowish brown crystal
hemosiderin
this is usually happens through phagocytosis
extravascular hemolysis
