Read the following statements.
I. Adam's apple in man is formed by thyroid cartilage.
II. The maximum volume of air a person can breath in after forced expiration is vital capacity.
III. About 20-25% of CO, is transported as carbaminohaemoglobin.
IV. Pneumotaxic centre lies in pons.
The correct statement(s) is

Only I

I, II

I, II, III

I, II, III, IV

Solution

I, II, III, IV

Adam's apple is a projection in front of neck formed by thyroid cartilage of the larynx, more prominent in man. Vital capacity is the maximum volume of air that person breaths out after forceful inspiration.

VC= ERV+ TV+ IRV

CO₂ is carried by heamoglobin in the form of carbamino haemoglobin, partial pressure of O₂ affects this binding. Pons Varolii of brain act as a pneumotaxic centre, which regulates rhythm of breathing mechanism.