Which structure is lined with simple squamous epithelium? which structure is lined with simple squamous epithelium? oropharynx nasopharynx trachea alveolus?

The correct answer is alveolus.

A simple squamous epithelium is a single layer of flat cells in contact with the basal lamina which is often extremely thin, permeable and it offers very little protection. The simple squamous epithelium is associated with filtration and diffusion and it is found in structures like the outer layer of skin, capillaries, alveoli or glomeruli.