Question

How might RBC production be altered to compensate for changes to hemoglobin that result in an abnormally high affinity for O2?

Answer 1

ANSWER :-) Blood is a specialized body fluid. Blood has many different functions, including:

• carrying the cells and antibodies that fight infection
• bringing out of waste products to the kidneys and liver, which filter and clean the blood

• transport of  oxygen and nutrients to the lungs and tissues
• formation of blood clots to prevent excess blood loss
• regulating body temperature

Blood consists of four components :- red blood cells,white blood cells, plasma and platelets.

PLASMA : It is the main constituent of blood and it mainly consists of water with protiens,nutrients,,ions in it. The plasma is about 90% percent water, with the remaining 10%, percent made up of ions, proteins, nutrients, wastes, and dissolved gases. The ions, proteins, and other molecules found in plasma are responsible for maintaining pH of blood and osmotic balance.

PLATELETS :- It is the main factor which is responsible for clotting.Platelets, also called thrombocytes, are cell fragments involved in blood clotting. A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Having more than 450,000 platelets is a condition called thrombocytosis and having less than 150,000 is known as thrombocytopenia.

WHITE BLOOD CELLS :- they form vital defenses against disease and infection.These are also called as leukocytes.The normal range of the number of white blood cells in a microliter of blood is between 3,700 and 10,500.

RED BLOOD CELLS :- Aother constituent of blood also called as red blood corpuscles whose main function is to carry or transport the oxygen from lungs to tissues and remove carbon dioxide from body,transporting to the lungs.

RBC's contains a protien which is called haemoglobin which is responsible for carrying oxygen from lungs to all the body tissues.Haemoglobin can be saturated with oxygen molecules (oxyhemoglobin), or desaturated with oxygen molecules (deoxyhemoglobin)

Oxygen affinity is measured as the partial pressure of oxygen to saturate 50 per cent of hemoglobin .Hemoglobin oxygen affinity is the continuous relationship between hemoglobin oxygen saturation and oxygen tension.

Oxyhemoglobin :- Formed when the oxygen binds to the heme component of the protein hemoglobin in red blood cells. This process occurs in the pulmonary capillaries adjacent to the alveoli of the lungs. The oxygen then travels through the blood stream which is to be dropped off at cells where it gets utilized as a terminal electron acceptor in the production of ATP by the process of oxidative phosphorylation. It does not, however, help to counteract a decrease in blood pH. Ventilation, or breathing, may reverse this condition by removal of carbon dioxide, thus causing a shift up in pH.

Hemoglobin exists in two forms, a taut (tense) form (T) and a relaxed form (R). Various factors such as low pH, high CO₂ and high 2,3 BPG at the level of the tissues favor the taut form, which has low oxygen affinity and releases oxygen in the tissues. Conversely, a high pH, low CO₂, or low 2,3 BPG favors the relaxed form, which can better bind oxygen.

The partial pressure of the system also affects O₂ affinity where, at high partial pressures of oxygen (such as those present in the alveoli), the relaxed (high affinity, R) state is favoured. Inversely, at low partial pressures , the (low affinity, T) tense state is favoured.

Moreover, the binding of oxygen to the iron(II) heme pulls the iron into the plane of the porphyrin ring, causing a slight conformational shift. The shift encourages oxygen to bind to the three remaining heme units within hemoglobin (thus, oxygen binding is cooperative).

Another reason  of Hb-O₂ affinity that is relevant to exercise is a change in body temperature .

Therefore, somehow RBCs production gets altered.