91Ó°ÊÓ

Assertion: 70 per cent of \(\mathrm{CO}_{2}\) is carried as bicarbonate ion in plasma. Reason: If it is transported directly then \(\mathrm{pH}\) of blood becomes acidic.

Assertion: In mammals, complex respiratory system has developed. Reason: Mammalian skin is impermeable to gases.

Assertion: Emphysema is a chronic disorder. Reason: One of the major cause of emphysema is cigarette smoking.

Assertion: Respiratory rhythm is maintained by the respiratory centre in medulla region of brain. Reason: A chemosensitive area in the medulla can alter the respiratory mechanism.

Assertion: The maximum amount of \(\mathrm{CO}_{2}\) is converted into bicarbonate ion in RBCs. Reason: RBCs contain a very high concentration of the enzyme, carbonic anhydrase.

Assertion: Blood of insects is colourless. Reason: The blood of insect does not play any role in transport of oxygen.

Assertion: The amount of \(\mathrm{CO}_{2}\) that can diffuse through the diffusion membrane per unit difference in partial pressure is much higher when compared to that of \(\mathrm{O}_{2}\). Reason: The solubility of \(\mathrm{CO}_{2}\) is 20 to 25 times higher than that of \(\mathrm{O}_{2}\).

Assertion: Trachea, primary, secondary and tertiary bronchi and terminal bronchioles are non-collapsible. Reason: They all are supported by incomplete cartilaginous ring

Assertion: Human breathing is negative pressure breathing. Reason: Air drawn in lungs because of pressure less than atmospheric pressure in lungs during inspiration

Assertion: Functional residual capacity is equal to ERV+RV Reason: Expiratory capacity is equal to TV+IRV