Parenchyma

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== Parenchyma ==

Parenchyma is a term used in biology and anatomy to describe the functional tissue in plants and animals. It is distinct from the stroma, which refers to the supportive or connective tissue. Parenchyma is essential for the proper functioning of various organs and systems.

In Plants

In botany, parenchyma refers to a type of plant tissue that is composed of living cells with thin cell walls. These cells are often found in the mesophyll of leaves, the cortex and pith of stems, and the roots of plants. Parenchyma cells are involved in various functions, including photosynthesis, storage, and secretion.

Types of Parenchyma in Plants

• **Chlorenchyma**: Parenchyma cells containing chloroplasts and involved in photosynthesis.
• **Aerenchyma**: Parenchyma with large air spaces, aiding in gas exchange and buoyancy in aquatic plants.
• **Storage Parenchyma**: Cells that store nutrients, such as starch, oils, and water.

In Animals

In zoology and human anatomy, parenchyma refers to the functional tissue in organs, as opposed to the connective tissue or stroma. For example, in the liver, the parenchyma consists of hepatocytes, while in the lungs, it includes the alveoli and associated structures.

Examples of Parenchyma in Animals

• **Liver**: The parenchyma is made up of hepatocytes, which perform various metabolic, detoxification, and synthetic functions.
• **Lungs**: The parenchyma includes the alveoli, where gas exchange occurs.
• **Kidneys**: The parenchyma consists of nephrons, the functional units responsible for filtering blood and producing urine.

Functions

Parenchyma serves several critical functions depending on its location and the organism:

• **Photosynthesis**: In plants, chlorenchyma cells perform photosynthesis.
• **Storage**: Parenchyma cells store nutrients and water.
• **Gas Exchange**: Aerenchyma facilitates gas exchange in aquatic plants.
• **Metabolism**: In animals, parenchymal cells in organs like the liver and kidneys are involved in metabolism and detoxification.

Characteristics

Parenchyma cells are generally characterized by:

• Thin cell walls
• Large central vacuoles
• Ability to divide and differentiate
• Presence in both primary and secondary tissues

Related Topics

• Tissue (biology)
• Stroma (tissue)
• Mesophyll
• Hepatocyte
• Alveolus (lung)
• Nephron

See Also

• Collenchyma
• Sclerenchyma
• Ground tissue