thin-walled. living cells capable of dividing and essential in photosynthesis. radial transport. energy storage. and production of protective compounds.
parenchyma cells (Wikipedia)
Parenchyma (/pəˈrɛŋkɪmə/) is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Emphysema%2C_bullous%2C_subpleural_and_honeycomb_fibrosis_%284563270966%29.jpg/350px-Emphysema%2C_bullous%2C_subpleural_and_honeycomb_fibrosis_%284563270966%29.jpg)
Lung parenchyma showing damage due to large subpleural bullae.