Hemoglobin and Gas Transport

Oxygen Transport

• Hemoglobin is responsible for carrying oxygen in the blood.
• The molecular weight of Hemoglobin is 64,500 g/mol.
• Each Heme in Hemoglobin can bind reversibly with 1 oxygen molecule.

Atmospheric Pressure and Oxygen

• The barometric pressure of air at sea level is 760 mmHg.
• The partial pressure of oxygen at sea level is 159 mmHg.

Oxyhemoglobin Dissociation Curve

• The sigmoidal shape of the oxyhemoglobin dissociation curve is physiologically significant because it allows for efficient oxygen delivery to tissues.

Binding of Gases to Hemoglobin

• Oxygen, carbon dioxide, and carbon monoxide can bind to hemoglobin.

Red Blood Cells and Oxygen Transport

• Red blood cells play a crucial role in the transport of oxygen and carbon dioxide.
• Oxygen is transported from lungs to tissues, whereas carbon dioxide is transported from tissues to lungs.

Factors Affecting Oxyhemoglobin Dissociation Curve

• The oxyhemoglobin dissociation curve can shift in response to changes in pH, temperature, and 2,3-bisphosphoglycerate (2,3-BPG) levels.

Carbon Dioxide Transport and Buffering

• Red blood cells are important for CO2 transport and buffering of hydrogen ions.
• Carbon dioxide is transported in the blood as carbaminohemoglobin, bicarbonate, and dissolved CO2.

Carbon Dioxide Transport

• Carbon dioxide is not transported in the blood as carbonic acid.

Solubility of Gases

• Carbon dioxide is more soluble in blood than oxygen.

Buffering Agents

• The major buffer agent in the body is bicarbonate.

Chloride Shift

• The chloride shift is the process where chloride ions are exchanged for bicarbonate ions to get bicarbonate into the plasma.

Effect of Oxygen Binding on Carbon Dioxide Binding

• When more oxygen is bound to hemoglobin, the binding of carbon dioxide to hemoglobin is reduced.

Effect of Oxygen Binding on pH

• When more oxygen is bound to hemoglobin, the pH of hemoglobin increases.

Carbon Dioxide Transport Promotion

• The Bohr effect promotes the transport of carbon dioxide in the blood.

Carbon Dioxide Partial Pressure

• The typical operating range for carbon dioxide partial pressure in the body is 40 mmHg.
• The concentration of carbon dioxide in the blood is approximately 48 mmol/L.

Reason for Carbon Dioxide Transport

• The main reason for transporting carbon dioxide in the blood is to remove waste products from the body.

Calculating Partial Pressure of Oxygen

• The equation for calculating the partial pressure of oxygen at sea level in air is PaO2 = (PiO2 x FiO2) - (PaCO2 / RQ).

Alveolar-Arterial PO2 Difference

• The normal Alveolar-arterial PO2 difference in a healthy patient is approximately 10-15 mmHg.

Carrying Capacity for Dissolved Oxygen

• The carrying capacity for dissolved oxygen in blood at a PaO2 of 100 mmHg is 0.003 mL O2/mL blood.

Hemoglobin Content

• The normal range for hemoglobin content in men is 13.5-17.5 g/dL.

Oxygen Binding to Hemoglobin

• Oxygen binds to site 4 of hemoglobin at a PO2 of approximately 26 mmHg.

Carbaminohemoglobin

• Carbaminohemoglobin is hemoglobin bound to carbon dioxide.

Effect of Blood Flow on Tissue PO2

• Increasing blood flow to a tissue increases tissue PO2.

Effect of Carbon Monoxide on Hemoglobin

• Carbon monoxide binds to hemoglobin, reducing its oxygen-carrying capacity.

Total Oxygen Concentration in Blood

• The equation for calculating the total oxygen concentration in blood is [O2]total = [O2]bound + [O2]dissolved.

Deoxyhemoglobin

• Deoxyhemoglobin is hemoglobin without oxygen bound.