Lecture 1 Flashcards
All cells come from what single cell type in the bone marrow?
Pluripotent Hematopoietic Stem Cell (PHSC)
First cell that is identified as part (beyond stem cell) of red cell series is called?
PRO-ERYTHROBLAST
Various stages that you can see on the left - divides from Pro-erythroblasts to mature RBC (erythrocytes)
During the stages of RBC production, what specific steps take place?
1. The Nucleus condenses to a small size and then finally is reabsorbed within the cell or extruded from the cell
2. Endoplasmic Reticulum in the cell is Also reabsorbed
At this stage there can be remnants of Mitochondria* & the *Golgi Apparatus and that’s when you can see the Reticulocyte
During the RETICULOCYTE STAGE:
3. The cell actually travels from the bone marrow → the circulation/blood
4. Where it is then squeezed through the pores of the capillary membrane (diapedesis)
5. Then in 1 - 2 Days = The bluish/ blackish remnants disappear completely and the cell matures = ERYTHROCYTE
What is the reticulocyte concentration of a NORMAL blood smear?
Reticulocyte Count is LOW
What is the reticulocyte concentration of an ANEMIC blood smear?
RETICULOCYTE Count HIGH
What is the most important determinant of RBC production?
TISSUE OXYGENATION
Wat are some other factors that will stimulate an INCREASE in RBC production?
- High Altitude
- LOW PaO2
Define Hematocrit (HCT).
HCT is the Fractional Volume of RBC Mass
Define Hemoglobin (Hgb).
Hemoglobin is the Main “Blood Protein”
- Carries oxygen
How to calculate HCT using Hgb?
Hgb X 3 = HCT
How does volume status effect HCT?
Hypovolemia = vasculature would be more HEMOCONCETRATED.
This individual may not have adequate O2 carrying capacity, even though the HCT is normal
What is the NORMAL RBC count for a Male?
Male
- 7 - 6.1 million cells per microliter (cells /mcL)
(5. 2 Million cells /mcL)
What is the NORMAL RBC count for Females?
Female
- 2 to 5.4 million cells/ mcL
(4. 7 Million)
What are the three blood indices and what information does it provide?
Indices: – describe size and the hgb concentration
- MCV (Mean Corpuscular Volume: Measures the average Size + Volume of RBC)
- MCH (Mean Corpuscular Hemoglobin)
- MCHC (Mean Corpuscular Hemoglobin Concentration)
What is NORMAL MCV (Mean Corpuscular Volume)?
★Normal: 80 - 100
Normocytic Anemia
If MCV Elevated then = MACROCYTIC Anemia
If MCV Decreased, then = MICROCYTIC Anemia (Small RBC)
What is NORMAL Mean Corpuscular Hemoglobin?
★Normal: 25 - 30 (Normochromic) Anemia
MCH < 25: Hypochromic Anemia
MCH > 30: Hyperchromic Anemia
What is NORMAL MCHC (Mean Corpuscular Hemoglobin Concentration)
★Normal: 30 - 35
What is Erythropoietin?
What stimulates Erythropoietin release?
Where is Erythropoietin formed?
Erythropoietin
Glycoprotein Hormone
Stimulates RBC production in hypoxia
Formed in the kidneys - 90%
Without Erythropoietin, RBC production WOULD NOT INCREASE
What are some other factors that stimulate Erythropoietin production?
Epinephrine
Norepinephrine
Prostaglandins
What are some Nutritional Requirements for RBC Production?
B-12
Folic acid
A DECREASE in either of these requirements results in a MACROCYTIC anemia – cells are LARGER than normal
What is the MAJOR FUNCTION of the RBCs?
To TRANSPORT HEMOGLOBIN
Define Anemia?
Anemia: DECREASED Oxygen Carrying Capacity
What is the Carbonic Acid Equation?
CO2 + H2O —> H2CO3 —> H+ + HCO3
How does RBC contribute to the carbonic acid reaction?
RBC carries a large amount of Carbonic Anhydrase
An enzyme that catalyzes the reaction between CO2 + H2O to form Carbonic Acid
This reaction allows the blood to carry LARGE amounts of CO2, In the form of Bicarbonate Ions (HCO3-)
From the dissociation of carbonic acid to Bicarbonate Ions HCO3-
From the tissues to the lungs where it is converted back into CO2 and exhaled as waste
What is the lifespan of RBCs?
Lifespan of 120 days
What is the shape of a normal RBC?
Biconcave disk with a diameter of 7.8 microns
How much Oxygen can 1 g of Hgb carry?
1.39/ 1.34 ml/ O2
What are some causes of Anemia (decreased O2 capacity)?
- DECREASE in # RBC (quantitative decrease in normal Hgb)
Decrease in RBC production (bone marrow problems due to chemo or radiation)
Lysis of cells (premature destruction)
- Abnormalities in HGB (qualitative problem → Sickle Cell)
The RBC of the sickle cell disease are miss shaped.
They can clog small capillaries and cause ischemia
- Lysis of RBC – d/t a structural disorder - often inherited
- Disorders affecting RBC metabolism
Including the pathway of glycolysis:
G6PD Deficiency (glucose 6 phosphate dehydrogenase deficiency) = found mostly in African, Asian, middle eastern and Mediterranean descent
Define Sickle Cell disease?
Hemolytic Anemia, Inherited: autosomal recessive disease
-There is a substitution of a Valine for Glutamic Acid in beta-globin subunit (Hgb S instead of Hgb A)
What are some “triggers” that causes the formation of Hgb S?
Hemoglobin “S” Triggers:
Acidosis (acidotic environment)
Hypoxemia (Pa02 < 40 mmHg )
HypOthermic
HypOvolemic (dehydration)
As result of the trigger, those RBCs will have conformational change and sickle – elongating of red cell to sickle shape
What is the problem with the body forming Hgb “S”?
Problem: The sickled RBCs will clog up blood vessels.
This will cause an infarction in various organs that aren’t getting circulation/oxygenation that is needed
There can also be sequestration of RBC in the liver and spleen
Also, pain
What is the difference between the HOMOZYGOUS and HETEROZYGOUS forms of Sickle Cell Disease?
Homozygous form causes the disease
Heterozygous form is only the trait