Question

Match the functions of the cells in the Alveoli.

$\begin{array}{cc}ColumnI& ColumnII\\ i.Type1pneumocytes& a.Producessurfactant\\ ii.Type2pneumocytes& b.Macrophages\\ iii.Type3pneumocytes& c.Exchangeofgases\end{array}$

• A. i) - c., ii) - b., iii) - a.
• B. i) - c., ii) - a., iii) - b.
• C. i) - b., ii) -c., iii) - a.
• D. i) - a., ii) -c., iii) - b.

Answer 1

The correct option is B

i) - c., ii) - a., iii) - b.

The alveoli have three types of alveolar cells or pneumocytes. Type 1 pneumocytes consists of squamous cells. These are the cells across which gas Exchange takes place. The second type of cells is Type 2 pneumocytes, which produce a surfactant substance that prevents the alveoli from collapsing. The surfactant is an elastic substance that allows the expansion and contraction of the lungs. This substance gives elasticity to the lungs allowing it to expand and contract as we breathe in and out. The third type of cells (Type 3 pneumocytes) are the macrophages which are responsible for removing foreign bodies be it bacteria, dust, damaged blood cells etc.