Question

Which one of the following is the correct statement for respiration in humans?

• A. About 90% of carbon dioxide (CO2) is carried by haemoglobin as carbaminohaemoglobin.
• B. Neural signals from the pneumotaxic centre in the pons region of the brain can increase the duration of inspiration.
• C. Workers in grinding and stone-breaking industries may suffer from lung fibrosis.
• D. Cigarette smoking may lead to inflammation of bronchi.

Answer 1

The correct option is C Workers in grinding and stone-breaking industries may suffer from lung fibrosis.

• Workers in grinding and stone-breaking industries may suffer from lung fibrosis. Lung fibrosis is an occupational respiratory disorder where the dust produced is so high that the body’s defence mechanism is unable to cope. The prolonged exposure results in proliferation of fibrous tissue in the lung which causes serious damage.
• About 97% of oxygen is transported by RBCs in the blood. About 20 – 25% of carbon dioxide is carried by haemoglobin as carbaminohaemoglobin.
• Cigarette smoking is the leading cause of emphysema.
• Neural signals from the pneumotaxic centre in the pons region of the brain can reduce the duration of inspiration and thereby alter the respiratory rate.