Pneumotaxic centre which can moderate the functions of the respiratory rhythm centre is present at:

1. Pons region in brain

2. Thalamus

3. Spinal cord

4. Right cerebral hemisphere

Haemoglobin is:

1. An oxygen carrier in human blood

2. A protein used as a food supplement

3. An oxygen scavenger in root nodules

4. A plant protein with high lysine content

The majority of carbon dioxide produced by our body cells is transported to the lungs:

1. dissolved in the blood

2. as bicarbonates

3. as carbonates

4. attached to haemoglobin

The exchange of gases in the alveoli of the lungs takes place by:

1. osmosis

2. simple diffusion

3. passive transport

4. active transport

What is another name for the windpipe?

1. Trachea

2. Larynx

3. Oesophagus

4. Lungs

Dead space air in man is:

1. 500 mL

2. 150 mL

3. 250 mL

4. 1.5 L

The 'blue baby' syndrome results from:

1. excess of chloride

2. methaemoglobin

3. excess of dissolved oxygen

4. excess of TDS (Total Dissolved Solids)

The effect of cigarette smoking and radon in combination on lungs is:

1. Fatal

2. Synergistic

3. Mutualistic

4. Antagonistic

Amount of CO₂ in expired air is about:

1. 0.04%

2. 0.03%

3. 4.5%

4. 21%