Alveoli in mammalian lungs are adapted for rapid gas exchange. The alveolar wall is composed of two main types of epithelial cells:
- Type II pneumocytes, which are cuboidal cells that secrete alveolar surfactant.
- Type I pneumocytes, which are extremely thin, flattened squamous cells designed to minimise diffusion distance.
The table below shows the surface area, volume, and surface area to volume ratio of these two cell types.
| Type of cell | Surface area in μm2\mu\text{m}^2μm2 | Volume in μm3\mu\text{m}^3μm3 | Surface area to volume ratio |
|---|---|---|---|
| Type II pneumocyte (cuboidal) | 3,500 | 70,000 | 1 : 20 |
| Type I pneumocyte (squamous) | 24,000 | 36,000 | ? |
Calculate the surface area to volume ratio of the Type I pneumocyte. Give your answer in the same format as the Type II pneumocyte.