Parenchyma
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Parenchyma (Template:IPAc-en)Template:RefnTemplate:Refn is the bulk of functional substance in an animal organ such as the brain or lungs, or a structure such as a tumour. In zoology, it is the tissue that fills the interior of flatworms. In botany, it is some layers in the cross-section of the leaf.<ref>Template:Cite web</ref>
Etymology
The term parenchyma is Neo-Latin from the Ancient Greek word Template:Lang Template:Lang meaning 'visceral flesh', and from Template:Lang Template:Lang meaning 'to pour in' from Template:Lang Template:Lang 'beside' + Template:Lang Template:Lang 'in' + Template:Lang Template:Lang 'to pour'.<ref>Template:Cite book</ref>
Originally, Erasistratus and other anatomists used it for certain human tissues.<ref>Virchow, R.L.K. (1863). Cellular pathology as based upon physiological and pathological histology [...] by Rudolf Virchow. Translated from the 2nd ed. of the original by Frank Chance. With notes and numerous emendations, principally from MS. notes of the author. 1–562. [Cf. p. 339.] link Template:Webarchive.</ref> Later, it was also applied to plant tissues by Nehemiah Grew.<ref>Gager, C. S. 1915. The ballot for names for the exterior of the laboratory building, Brooklyn Botanic Garden. Rec. Brooklyn Bot. Gard. IV, pp. 105–123. link Template:Webarchive.</ref>
Structure
The parenchyma is the functional parts of an organ, or of a structure such as a tumour in the body. This is in contrast to the stroma, which refers to the structural tissue of organs or of structures, namely, the connective tissues.Template:Citation needed
Brain
Template:AnchorThe brain parenchyma refers to the functional tissue in the brain that is made up of the two types of brain cell, neurons and glial cells.<ref>Template:Cite web</ref> It is also known to contain collagen proteins.<ref>Template:Cite journal</ref> Damage or trauma to the brain parenchyma often results in a loss of cognitive ability or even death. Bleeding into the parenchyma is known as intraparenchymal hemorrhage.<ref name="Freeman WD-2012">Template:Cite journal </ref>
Lungs
Lung parenchyma is the substance of the lung that is involved with gas exchange and includes the pulmonary alveoli.<ref name="Suki-2011">Template:Cite journal</ref>
Liver
The liver parenchyma is the functional tissue of the organ made up of around 80% of the liver volume as hepatocytes. The other main type of liver cells are non-parenchymal. Non-parenchymal cells constitute 40% of the total number of liver cells but only 6.5% of its volume.<ref name="Kmieć Z-2001">Template:Cite book</ref>
Kidneys
The renal parenchyma is divided into two major structures: the outer renal cortex and the inner renal medulla. Grossly, these structures take the shape of 7 to 18<ref>Template:Cite journal</ref> cone-shaped renal lobes, each containing renal cortex surrounding a portion of medulla called a renal pyramid.<ref name="Boron-2004">Template:Cite book</ref>
Tumors
The tumor parenchyma, of a solid tumour, is one of the two distinct compartments in a solid tumour. The parenchyma is made up of neoplastic cells. The other compartment is the stroma induced by the neoplastic cells, needed for nutritional support and waste removal. In many types of tumour, clusters of parenchymal cells are separated by a basal lamina that can sometimes be incomplete.<ref name="Connolly-2003">Template:Cite journal</ref>
Flatworms
Parenchyma is the tissue made up of cells and intercellular spaces that fills the interior of the body of a flatworm, which is an acoelomate. This is a spongy tissue also known as a mesenchymal tissue, in which several types of cells are lodged in their extracellular matrices. The parenchymal cells include myocytes, and many types of specialised cells. The cells are often attached to each other and also to their nearby epithelial cells mainly by gap junctions and hemidesmosomes. There is much variation in the types of cell in the parenchyma according to the species and anatomical regions. Its possible functions may include skeletal support, nutrient storage, movement, and many others.<ref>Template:Cite journal</ref>