PATHOLOGY

Detailed explanation-1: -Trachea is divided into fine branches known as tracheoles. Tracheoles have thin and moist walls to increase the efficiency of gaseous exchange. The large number of tracheoles also provides a large surface area to facilitate gaseous exchange through diffusion directly into the cells.

Detailed explanation-2: -Thin lining: the lining of the alveoli is very thin so that gases can quickly diffuse through it. Large surface area: human lungs contain about 500 million alveoli, which creates a surface area around half the size of a tennis court. This speeds up diffusion because gases have more area over which to diffuse.

Detailed explanation-3: -Although all parts of the tracheal system allow oxygen to diffuse out to the tissues and carbon dioxide to enter, most of the gas exchange occurs across the smaller tracheae and tracheoles because they are the parts of the system in intimate contact with cells.