parenchymatous

Parenchymatous is an adjective used in biology to describe tissues composed primarily of parenchyma, the functional tissue of an organ or plant. The term is used in both botanical and anatomical contexts to indicate that parenchyma constitutes the main, active component of the tissue rather than supporting or connective elements.

In plants, parenchyma is a simple, living tissue with thin primary cell walls. Plant parenchyma cells are often isodiametric with large central vacuoles and are capable of division. They carry out photosynthesis (chlorenchyma), store carbohydrates, oils, and pigments, and participate in wound repair and regeneration. Parenchyma also differentiates into specialized forms such as aerenchyma, which includes air spaces to aid flotation and gas exchange, and storage parenchyma, which stores starches and other reserves.

In animals and, to some extent, fungi, parenchyma refers to the functional tissue of an organ, as opposed to its stroma or supportive framework. Parenchymal cells perform the organ’s specific activities; for example, hepatocytes compose the hepatic parenchyma and carry out metabolic and detoxification functions. The term parenchymatous may be used to describe tissue that is dominated by such functional cells rather than by connective, vascular, or supportive elements.

The concept emphasizes the functional, cellular component of tissues. The exact composition and significance of parenchyma vary among organs and taxa, but parenchymatous tissue generally indicates that the parenchymal cells are the principal constituent.