HEMOGLOBIN (Hb)
HEMOGLOBIN is the chemical that transports O2 and CO2 and is formed by amino acids creating globulin, and a heme portion, which consists of iron atoms and a red pigment called porphyrin. Each gram of hemoglobin can carry 1.34 milliliters of oxygen in 100Ml's of blood. Hb also acts as a buffer in the extracellular fluid.
For example, when O2 content in tissues is low and CO2 and H+ ions are high (causing a low pH), oxygen dissociates from Hb faster.
The unoxygenated Hb then binds to the H+ ions thereby raising the pH.
As CO2 diffuses into the RBC it is converted into bicarbonate via carbonic anhydrase.
As the protons bond to the Hb the bicarbonate ions leave the cell and for ever one that leaves a chloride ion enters the RBC.
The efficiency of this buffer system rely's on properly functioning lungs for the elimination of CO2 and bicarbonate ions.
Increased Hb is found in:
1. Polycythemia vera
2. Congestive heart failure
3. Chronic obstructive pulmonary disease
4. Hemorrhages and burns
5. Thymus malfunctions
Decreased Hb is found in:
1. Anemia
2. Iron deficiency, thalassemia, pernicious anemia, and hemoglobinopathy's
3. Liver disease and hypothyroidism
4. Hemorrhage
5. Hemolytic anemia caused by infectious agents, drugs, and transfusions
6. Systemic diseases such as Hodgkin's, leukemia, lymphoma, SLE, sarcoidosis and renal cortical necrosis
7. Spleen conditions