Parenkymvev

Parenkymvev, also referred to as parenchymal tissue, is the functional tissue of an organ, composed of the cells that carry out its primary physiological activities. It stands in contrast to the organ’s stroma, which provides the supportive framework including connective tissue, blood vessels and nerves.

In animals and humans, parenchymal cells are organ-specific. In the liver, hepatocytes form the major parenchyma and perform metabolism, bile production and detoxification. In the kidney, tubular epithelial cells and secretory cells constitute the functional parenchyma. In the lung, the alveolar and bronchiolar epithelium carries out gas exchange. In the brain, neurons and many glial cell types make up the neuronal parenchyma, the tissue responsible for processing information and coordinating activity.

Parenkymvev also exists in plants. Plant parenchyma is a simple, living tissue with relatively thin cell walls. It serves multiple functions depending on specialization: chlorenchyma carries out photosynthesis; storage parenchyma stores starch and other nutrients; aerenchyma forms air spaces; and more generally it participates in wound repair and regrowth.

Pathology and regeneration: Disease or injury often targets parenchymal cells, leading to loss of organ function. Parenchymal disease may be contrasted with diseases of other tissue components; in the liver, extensive parenchymal damage can progress to fibrosis and cirrhosis. Some organs, such as the liver, display notable regenerative capacity, whereas others have limited repair after parenchymal injury.

See also: stroma; parenchyma; hepatic parenchyma.