The Nitty before The Gritty Flashcards
This protein is a regulator of ferroportin
Hepcidin
Male: RBC count, Hgb, & HCT Normal Ranges
RBC: 4.5 - 5.9 x 10^6 (△ 1.4)
Hgb: 13.5 - 17.5 x 10^3 (△ 4.0)
HCT: 41.0 - 53.0 (△12.0)
Female: RBC count, Hgb, & HCT Normal Ranges
RBC: 4.0 - 5.2 x 10^6 (△1.2)
Hgb: 12.0 - 16.0 x 10^3 (△4.0)
HCT: 36.0 - 46.0 (△10.0)
MCV, MCH, MCHC Normal Ranges
MCV: 80 - 96 (△20%)
MCH: 29 - 32 (△10%)
MCHC: 33.4 - 35.5 (△~5.0%)
What are the two morphological traits that can be used to categorize anemias?
MCV & MCHC
What is the form of most ingested Fe?
Ferric State (Fe3+)
What is the purpose of DCYTB?
Reductase enzyme to convert ingested Fe from Ferric (3+) to Ferrous (2+) for optimal absorption.
DCYTB = Duodenal Cytochrome B
Which of these is the optimal environment for Fe absorption?
a. Basic
b. Acidic
c. Amphoteric
d. Neutral
B. Acidic
Optimal pH is <4.0 for reducing agents such as ascorbic acid
What protein moves Ferrous iron into the enterocyte?
DMT1 (Divalent Metal Transporter 1)
What two proteins are required for transport of iron out of the enterocyte?
Ferroportin 1 (FPN1, for transport out)
Hephaestin (for oxidization of Fe to the Ferric state)
Note: Hephaestin is a copper-dependant enzyme
Hepcidin is produced by what organ?
Liver
Which of these cells does FPN1 NOT transport iron out of?
a. Enterocyte
b. Hepatocyte
c. Epithelial
d. Macrophage
C. Epithelial Cells
Match the functions to the correct cells (more than one may apply)
A. Macrophage
B. Enterocyte
C. Hepatocyte
- Iron Absorption
- Iron Storage
- Iron Recycling
A. 3
B. 1 & 2
C. 2
When the body Fe storage is low, what is the expected level of Hepcidin?
Hepcidin should also be low. It’s upregulated when Fe stores are adequate/high.
What protein is directly affected by the hemochromatosis gene (HFE) and how?
In an adequately supplied iron environment, HFE stimulates the production of Hepcidin in order to decrease FPN1 and thusly decreased iron transport.
The way I remember is “Hemochromasis gene stops hemochromatosis” by making hepcidin to stop FPN export of iron
Which iron enzyme is named after a Greek god?
Hephaestin (Hephaestus is the Greek god of metallurgy, metalworking, volcanoes, etc.)
Easy way to remember how Hepahestin functions is “Hephaestus needs metals to work with”, ie. copper-dependent and converts iron back to Ferric state
What is the relationship between EPO and Hepcidin?
EPO stimulates release of the hormone erythroferrone (ERFE), which suppresses Hepcidin.
What binds to Fe3+ to produce Transferrin?
Apotransferrin (binds to Fe3+ in serum after FPN1 transport out)
How many Fe3+ can Transferrin carry?
a. 4
b. 2
c. 8
d. None, it only carries the 2+ Ferrous state
b. 2 atoms of Fe3+ (Ferric)
What allows Transferrin to be internalized into nRBCs and Retics?
Transferrin Receptor 1(TfR1) on the surface of the RBC
Arrange the steps of Iron absorb & transport to RBCs in the right order:
a. Conversion to Fe3+ by Hephaestin
b. Transport of Fe2+ to enterocyte by DMT1
c. Conversion to Fe2+ by DCYTB
d. Transferrin picks up Fe3+ in circulation
e. Fe3+ ingested
f. FPN1 exports Fe3+ from enterocyte
g. Acidification of endosome to convert iron to Fe2+
h. Engulfment of transferrin via TfR1
i. Delivery of transferrin to nRBCS/Retics
j. Insertion of Fe2+ into protoporphyrin IX via ferrochelatase
k. Transport into cytoplasm by DMT1
l. DMT1 transport of Ferrous iron to mitochondria or stored as Ferritin
E–C–B–A–F–D–I–H–G–K–L–J
This one’s a long answer so apologies on that end lmao
What’s the calculation for MCV?
Bonus points: What’s the reference range?
(HCT/RBC) x 10 = MCV
Reference range is 80-96 fL
What’s the calculation for MCH?
Bonus points: What’s the reference range?
(Hgb/RBC) x 10 = MCH
Reference range is 29-32 pg
What’s the calculation for MCHC?
Bonus points: What’s the reference range?
(Hgb/HCT) x 100 = MCHC
Reference range is 33.4-35.5 %
State the calculation for corrected Reticulocyte %
Raw retic x (pt HCT/45) = corrected retic
State the calculation for Reticulocyte Maturation
1+ ((45 - pt raw %) x (0.1/Δ2%)) = Days Maturation
State the calculation for RPI
Bonus points: What’re the normal & marrow response reference ranges?
(Corrected %) / (Days Maturation) = RPI
Reference ranges: 0.5-1.5% for normal, >1.5% for marrow response
An increase in ERFE will result in what level of change for serum Fe?
a. Increased
b. Decreased
c. No net change
d. The question is misleading, ERFE directly affects ferrochelatase
A. Increased due to hepcidin suppression
