Blood Lecture 1 / Ch 4 Red Blood Cells Flashcards
Symptoms of Polycythemia Vera?
- Night Sweats
- Itching after hot bath
- Splenomegaly
- Plethora (Facial Redness)
- Hemorrhage or thrombosis
- Blurred Vision
- HTN
Prognosis for pts with PV is ?
10 - 16 yrs
Anemia
Hgb in males < 13
Hgb in females < 11
Symptoms of Anemia ?
- Dyspnea
- Weakness
- Pale
- Palpitations
- Headaches
- Sluggishness
Older Population:
- Cardiac Failure
- Angina pectoris
- Confusion
- Claudication (Impaired blood
flow) in the legs
Treatment for Anemia ?
- Increase RBC in circulation
- Administration of recombiant
Erythropoietin
Site in which O2 binds to Hgb?
Heme molecule
The exchange of O2 and CO2 occurs approximately how many times in the average life span of a RBC?
200,000
Affinity definition
tendency to bind, hold, pick up or to release O2
↑ CO2
↓ Ph ( Increased H+ content)
This occurs in metabolically active tissues, what can we expect of Hgb affinity?
Hgb would have less affinity for O2
↓ CO2
↑ Ph (Decrease H+ content)
This occurs in the lungs, what can we expect of Hgb affinity?
Hgb would have an increase in affinity for O2
Bohr effect definition
The influence of pH and CO2 on Hgb’s affinity to bind and to release O2
Hgb concentrations for:
- Females
- Males
- Newborns
- Females : 12-16
- Males 13.5-18
- Newborns 15-24
4 phases of fetal hemoglobin development.
- Gower I
- Gower II
- Portland
- Hgb F
How do adult and fetal Hgb differ?
Hgb F is designed to extract O2 from maternal cells at the placenta. They have a greater affinity for O2 than Hgb A.
Hgb Alpha polupeptide chains contain how many amino acids?
141
Hgb Bravo polupeptide chains contain how many amino acids?
146
HgbS = Sickle-cell anemia
– Predominantly among
African American
– Causes hemolysis
HgbF Present from ?
G4 to 6mo old
Heterozygous individuals for HgbS
Asymptomatic
Homozygous individuals for HgbS
They have 2 defective genes that code for the Hgb molecule.
HgbS results from what?
Substitution of the amino acid VALINE by GLUTAMIC ACID in position 6 in the beta chain.
What causes the sickle shape of the cell?
HbS transports O2 normally but deoxyhemoglobin S crystallizes and takes on the classic sickle shape.
Complications caused by HgbS?
- Discomfort
- Joint Pain
- Retinal degeneration
- Ulcerations of lower legs
- Infarctions of organs: Spleen and Liver.
- Priapism
Thalassemias
Individuals whose Hgb molecues show production of only 1 type of polypeptide chain.
- Genetic disorders in the production of α or β Hgb polypeptide chains
- Prevalent in persons with
Mediterranean or Asian
ancestry. - Low Hgb
- Fatigue
Individuals that produce only Alpha chains is said to have what?
Beta Thalassemias
minor
Individuals that produce only Beta chains is said to have what?
Alpha Thalassemias
(major)
- Blood transfusions required
2,3 DPG
AKA
2,3 (diphosphoglycerate)
- Produced by the breakdown of glucose. - Allows Hgb to release O2 to the tissues more easily. - Reversible storage Lesion - Bound 1:1 to Hgb
Hct index of the RBC in adults.
Males: 38 - 54%
Females: 38 - 46%
Infants: 55-68%
- This means that 38 - 54% of whole blood in a male is made up of red cells.
A transfusion of 1 unit of packed red cells would change the Hct by how much?
0.03 - 0.04
3 - 4%
When a Red cell ruptures, Hgb is released as what?
Plasma-Free-Hemoglobin
PFH
Generally PFH is metabolized in the liver into primarily what?
Bilirubin by the Kupfer Cells (macrophages)
In blood plasma, haptoglobin binds free hemoglobin (Hb) released from erythrocytes with high affinity and thereby inhibits its oxidative activity.Plasma Haptoglobin can bind the first 100 mg PFH / 100 ml of blood (safe solution)
• Once Haptoglobin is over whelmed, PFH diffuses into
tissues and renal tubules
If 300-500 ml blood is hemolyzed, what can we expect?
- Jaundice
- Renal failure
- CV collapse
- Decreased ABP
- Renal tubules blockage by precipitation of Hgb.
Adult Female Hgb / Hct
12 - 16 - 38 - 46
Adult Male Hgb / Hct
13.5 - 18 - 38 - 54
Infant Hgb / Hct
15 - 24 - 55 - 68
