Transport of Gases in Blood 189/1

What is the primary medium for the transport of O2 and CO2 in the body?

• Blood

• Cerebrospinal fluid

• Interstitial fluid

• Lymph

What percentage of O2 is transported by red blood cells (RBCs)?

• 97%

• 98%

• 90%

• 75%

How is the remaining 3% of O2 transported in the blood?

• Bound to hemoglobin

• Converted to carbon dioxide

• Carried by white blood cells

• Dissolved in plasma

What percentage of CO2 is transported by RBCs?

• 27%

• 23%

• 35%

• 30%

In what form is the majority of CO2 transported in the blood?

• Bicarbonate ions (HCO3-)

• Hemoglobin-bound CO2

• Carbonic acid (H2CO3)

• Dissolved CO2 gas

What is the role of haemoglobin in oxygen transport?

• Haemoglobin stores iron for the body.

• Haemoglobin breaks down carbon dioxide in the lungs.

• Haemoglobin regulates blood pressure.

• Haemoglobin transports oxygen from the lungs to the body's tissues.

How many molecules of O2 can one haemoglobin molecule carry?

• 6

• 2

• 4

• 8

What is the relationship between oxygen binding and partial pressure of O2?

• Oxygen binding is unaffected by the partial pressure of O2.

• Oxygen binding increases with higher partial pressure of O2.

• Oxygen binding decreases with higher partial pressure of O2.

• Oxygen binding is only relevant at low partial pressures of O2.

Name two factors that can interfere with the binding of oxygen to haemoglobin.

• Increased oxygen levels

• High altitude

• Low temperature

• Increased carbon dioxide levels, decreased pH (acidosis)

What type of curve is obtained when plotting percentage saturation of haemoglobin with O2 against pO2?

• Linear curve

• Exponential curve

• Sigmoidal curve

• Circular curve