Chap 7 Flashcards
Hemoglobin
Adult Male and Female Hgb Reference Ranges are?
Males= 13.5-18.0 g/dL
Females= 12.0-15.0 g/dL
Newborn and Children Hgb Reference Ranges are?
Newborns= 16.5-21.5 g/dL
Children 8-13= 12.0-15.0 g/dL
Hemoglobin
Iron-bearing protein and the main component of RBCs.
Hemoglobin gives RBCs what?
Its color
During what stage of Erythrocyte maturation, does the majority of Hgb synthesis take place?
Rubricyte (Polychromatophilic Normoblast) Stage
What regulates the production of Hemoglobin?
Tissue hypoxia
Tissue hypoxia causes the kidneys to do what?
Increase production of EPO, which increases RBC and hemoglobin production.
Functions of Hgb?
Carry oxygen from lungs to tissues.
Remove CO2
Buffering Action
What is the buffering action of Hgb?
Maintains blood pH as it changes from Oxyhemoglobin (W/ Oxygen) to Deoxyhemoglobin (w/o Oxygen).
How many polypeptide subunits make up the Hgb structure?
4
The heme group of a hemoglobin molecule is made of?
Porphyrin Ring
Ferrous Iron (Reduced state, Fe 2+)
The globin chains in a NORMAL PT are?
2 Alpha Chains
2 Beta Chains
Heme Synthesis takes place where?
The mitochondria of developing RBCs in the BM.
What processes are necessary for normal Hgb Synthesis?
Adequate Iron supply & delivery
Adequate synthesis of protoporphyrins
Adequate globin synthesis
Transferrin
Iron transporter
Protoporphyrin synthesis occurs where?
Mitochondria of RBC precursors.
What mediates protoporphyrin synthesis?
EPO and Vitamin B-6
Protoporphyrin + Iron=?
Heme
Porphyrin synthesis is proportional to the rate or?
Globin Synthesis
What determines proper globin synthesis?
Genes
the precise order of Amino acids in globin chains is critical for?
Structure and function of Hemoglobin.
What are the globin chain designations?
a- Alpha
B- Beta
d- Delta
e- Epsilon
y- Gamma
Z- Zeta
Embryonic Hemoglobins?
Gower-1
Gower-2
Portland
Gower-1 Hb is made of which globin chains?
2- Zeta
2-Epsilon
Gower-2 Hb is made of which globin chains?
2-Alpha
2-Epsilon
Portland Hb is made of which globin chains?
2-Zeta
2- Gamma
Fetal Hb is made of which globin chains?
2- Alpha
2-Gamma
What are the adult Hemoglobins?
HB A
HB A2
HB F
Hb A is made of which globin chains?
2- Alpha
2- Beta
Hb A2 is made of which globin chains?
2-Alpha
2-Delta
Hb F is made of which globin chains in adults?
2-Alpha
2-Gamma
What is the incidence of Hb A in adults?
95%
What is the incidence of Hb A2 in adults?
1.5-3.7%
What is the incidence of Hb F in adults?
<2%
Oxygen Affinity
The ease W/ which Hb binds and releases Oxygen.
When Hb has an increased oxygen affinity?
Hb binds more oxygen and doesn’t want to let go. (Kind of like Rick Astley….never gonna let you down)
Decreased Oxygen affinity?
Hb releases oxygen easier.
What can cause a right shift of the oxygen disassociation curve?
Increased H+
Increased CO2
Increased Temp
Increased 2,3-BPG
What can cause a left shift of the oxygen disassociation curve?
Decreased H+
Decreased CO2
Decrease in Temp
Decrease in 2,3-BPG
Acidic blood pH shifts?
Curve shifts right
Alkaline blood pH shifts?
Curve shifts left
When pH effects the oxygen disassociation curve its called?
Bohr Effect
A right shift means?
Hgb has less attraction to oxygen.
Hgb willing to release oxygen to tissues.
(I.E. Anemia, Acidosis)
Even W/ less RBCs, they act more efficiently to deliver oxygen to target.
A left shift means?
Hgb attracted to Oxygen
Less willing to release oxygen to tissues.
(I.E. Abnormal Hgb or Alkalosis).
Cyanosis
presence of > 5 g/dL deoxyhemoglobin in blood.
PTs appear blue
3 abnormal Hemoglobins?
Methemoglobin
Carboxyhemoglobin
Sulfhemoglobin
Methemoglobin could be caused by?
Hb M
Cytochrome b5 reductase deficiency
What is Hb M?
An inherited autosomal dominant pattern, W/ methemoglobin comprising 30-50% of total Hb in the body.
Sulfehemoglobin
an irreversible oxidation of Hb by drugs (Sulfanilamides, Phenacetin, Nitrites, Phenylhydrazine) or exposure to sulfur chemicals in an industry or environmental setting.
Carboxyhemoglobin
combination of carbon monoxide W/ heme iron.
What is Carbon Monoxide’s affinity for Hemoglobin?
240x that of oxygen
Causes of carboxyhemoglobin?
Inhaling car exhaust
Tobacco Smokers
Industrial Pollutants (Gas, Coal, Charcoal)