2. Anemia: Intro & Microcytic Flashcards
what blood cells should we normally see in peripheral blood?
basophil, eosinophil, bands, neutrophils, monocytes, platelets, RBCs, lymphocytes
lifespan of an RBC in peripheral blood?
120 days
a RBC contains what?
no nucleus, no organelles, no ability to synth proteins. contains hemoglobin, a few enzymes, glucose.
RBC function?
carries 02 to tissues, C02 away from tissues
erythropoiesis takes how long? where occurs?
7 days, in bone marrow
erythropoiesis: what substance declines in RBCs? what substance increases?
declines: RNA content
incr: hemoglobin
what is the last RBC form prior to release to peripheral blood?
reticulocyte. peripheral blood has 1% retics approx.
at what point does the RBC nucleus get extruded?
just prior to becoming reticulocyte.
what are the building blocks for RBCs?
iron, folate, B12
what organ senses 02 levels? what does it make to upregulate erythropoiesis?
kidney. makes erythropoietin (EPO)
what’s the diameter of an RBC?
7 microns
what percent of the RBC weight is hemoglobin?
33%
describe the outer membrane of an RBC and its internal structure
lipid bilayer, contains proteins that determine ABO blood type. fixed to reticular protein network (spectrin, ankyrin) which allow integrity but also flexibility.
normal adult Hgb is made up of what types of globin molecules?
97% Hgb A1: 2 alpha, 2 beta
2% Hgb A2: 2 alpha, 2 delta
1% fetal: 2 alpha, 2 gamma
Fetal Hgb is consists of of what?
4 globin chains: 2 alpha, 2 gamma
where is heme synthesized?
mitochondria
Hemoglobin consists of what, overall?
Heme (Fe + protoporphyrin) and Globin
Porphyria is a problem with what process?
the heme biosynthesis process in the mitochondria
thalassemia is a problem with what?
decr synthesis of the globin chain
what three things increase 02 affinity for heme?
incr pH, decr DPG, decr temp
what three things decrease 02 affinity for heme
decr pH, incr DPG, incr temp (think of what happens when the muscle exercises: lactic acidosis, incr temp, and just remember that DPG tracks along with the temp)
what is in plasma?
91% water, 7% blood proteins, 2% electrolytes, nutrients, hormones
what is the hematocrit (HCT)? approx normal value?
the percentage of blood volume (RBC + plasma) that is occupied by RBCs. should be around 45%.
what is the Hgb? unit? how does it relate to the HCT?
amount of hgb in the blood, in g/dL should be approx 1/3 HCT since 1/3 RBC weight is hemoglobin.
how does the WHO define anemia?
Hgb < 12 g/dL in women
Hgb < 13 g/dL in men
what does MCV stand for? what does it mean? normal value?
mean corpuscular volume. means the size of an average RBC. normal = 80-100
how would I estimate whether an RBC is micro-, macro-, or normocytic?
compare it to the size of a lymphocyte nucleus. normocytic if approx the same size.
MCH stands for what? means what?
mean corpuscular hemoglobin. means the average MASS of hgb per single RBC.
MCHC stands for what? means what?
mean corpuscular hemoglobin concentration. menas the CONCENTRATION of hgb in a volume of packed RBCs
in what disease states would you see low MCH? high MCH?
Low: iron def, thalassemia
high: macrocytosis
in what disease states would you see low MCHC? high MCHC?
Low: iron def, thalassemia
high: hereditary spherocytosis
in a normal RBC, how big should the central dimple be?
about 1/3 of the cell
with a low MCH/MCHC what is the appearance of the RBC?
hypochromic. big donut hole
with a high MCH/MCHC what is the appearance of the RBC?
hyperchromic. no donut hole because cell has –> spheroid.
RDW stands for what? means what? high RDW is called what?
Red Cell distribution width.
indicates variation in RBC size.
high RDW is called anisocytosis.
what percent of RBCs in peripheral blood are reticulocytes?
should be around 1%