Parenchyma cells have thin,
permeable primary walls enabling the transport of small molecules between them, and their cytoplasm is responsible for a wide range of biochemical functions such as nectar secretion, or the manufacture of secondary products that discourage herbivory.
Deposition of asbestos fibers in the Parenchyma of the lung may result in the penetration of the visceral
pleura from where the fiber can then be carried to the pleural surface, thus leading to the development of malignant mesothelial plaques.