What are chlorenchymal functions



Parenchyma (Gr. enchyma, the poured in, filling) denotes human, animal or vegetable base tissue. As a rule, the cells forming the tissue do not have any particular anatomical differentiation.

In animals

Parenchyma (Functional tissue) refers to the tissue formed by the functional cells of an organ (e.g. the nephrons of the kidney, the alveoli of the lungs, the white and red pulp of the spleen). In contrast to this is the interstitium, the subdividing connective tissue that does not take on any actual organ function, but contains the supplying and draining vessels and nerves. The parenchyma can also be called mesodermal connective tissue to indicate that it is formed by the mesoderm.

With plants

Parenchymal cell

    Parenchymal cells are thin-walled cells of the basic tissue that make up the majority of non-woody (herbaceous) plant structures (although in some cases their cell walls can be lignified) and serve, for example, to store nutrients. A distinction is made between several types.

Palisade parenchyma

The Palisade parenchyma or Palisade fabric is a plant tissue found in the leaves of higher plants below the upper epidermis. It consists of elongated, cylindrical cells and is mainly used for photosynthesis. Adjacent cells therefore resemble palisades if you look at a leaf cross-section with a light microscope. It should be noted, however, that the cells of the palisade parenchyma are not only arranged in a row, but also to form a surface. Intercellular cells are rare in this tissue. Palisade parenchyma cells contain around three to five times as many chloroplasts as sponge parenchyma cells. Leaves that are often exposed to sunlight (so-called sun leaves) have a multi-layered palisade parenchyma, while the palisade cells in shade leaves usually only form one layer so that the cells of the sponge parenchyma can also use the low light intensity.

Sponge parenchyma

The Spongy parenchyma or Sponge fabric is a plant tissue that occurs in the leaves of plants and borders the lower epidermis at the bottom and the palisade parenchyma at the top. It consists of mostly irregularly shaped, often star-shaped cells (then referred to as star parenchyma), between which there are larger intercellular spaces. Compared to the palisade parenchyma, the sponge parenchyma contains fewer chloroplasts. It is primarily used for gas exchange during photosynthesis, which is promoted by the intercellular system, as this results in the formation of large internal surfaces in the leaf. The trumpet tree, for example, was 5100 m2 Internal area measured at only 390 m2 outer leaf surface).


In general, a sponge parenchyma is only referred to as such if a palisade parenchyma is present in parallel.

Chlorenchyma (assimilation parenchyma)

The Chlorenchyma, also Assimilation parenchyma, is the parenchyma that specializes in photosynthesis. It is a chloroplast-rich leaf tissue (mesophyll), which consists of the palisade layer and the sponge parenchyma. The sponge parenchyma is both chlorenchyma and aerenchyma.

Aerenchyma

Under Aerenchyma one understands a form of the plant base tissue (parenchyma), in which the intercellular spaces are so wide that a real "ventilation tissue" is created. It occurs particularly in swamp and aquatic plants and is used to exchange gases in the submerged plant organs.

Hydrenchyma

Hydrenchyma can also be referred to as water storage parenchyma. It is mainly used by succulent plants to store water and has cells with very large vacuoles.

Storage parenchyma

Storage parenchyma serves to store nutrients.

See also

swell

  • Strasburger, Textbook of Botany, 35th edition, Spektrum Akademischer Verlag, 2002

Categories: Anatomy | Histology | Plant tissue