Hypodermis


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hypodermis

[‚hī·pə′dər·mis]
(botany)
The outermost cell layer of the cortex of plants. Also known as exodermis.
(invertebrate zoology)
The layer of cells that underlies and secretes the cuticle in arthropods and some other invertebrates.

Hypodermis

 

in invertebrates (for example, crustaceans, arachnids, and insects), the thin layer of usually cylindrical epithelium lying immediately under the cuticle (which is formed by the secretory activity of the cells of the hypodermis). The various cutaneous glands and the tactile and olfactory hairs are located in the hypodermis. In nematodes, gastrotrichs, and several other worms, the hypodermis is a syncytium that secretes the cuticle.

In plants, the hypodermis is one or more layers of cells located under the epidermis of the stems, leaves, seeds, and fruits, or under the epiblem (piliferous layer) of the roots. The hypodermis is part of the primary cortex of stems, often consisting of cells with thickened walls, and may be classified by function as mechanical tissue. It is most characteristic of succulents. In leaves the hypodermis consists of one, or more often several, layers of cells of aquiferous tissue (for example, in a number of tropical plants) or of mechanical tissue (for example, in pines and sago palms). In the leaf the hypodermis is formed when the cells of the epidermis are divided by septa that are parallel to the surface of the leaf, such as in Ficus and Begonia, or from cells of the mesophyll of the leaf tissue lying under the epidermis, such as in some palms. In roots the outer layers of cells of the primary cortex are sometimes called the exodermis.

References in periodicals archive ?
Plants, having revolute leaf margins and hypostomatic leaves with hypodermis, are common in some sclerophyllous scrub (Coastal chaparral) communities of Mediterranean-type climate in southern California or cool and high elevation (semi-arid) xerophytic plant communities in warm deserts (Gibson 1996).
He prepared detailed illustrations of four genera of Cactoideae--Mammillaria rhodantha, Cactus truncatus (= Schlumbergera truncata), Cereus curtisii (= Pilosocereus royenii), and Echinocactus eyriesii (= Echinopsis cyriensii)--emphasizing the epidermis, cuticle, and hypodermis.
The skin is composed of three closely related layers, an outer keratinizing stratified squamous epithelium called epidermis, an underlying tough supporting and nourishing layer of fibroblastic tissue, called dermis and a variable deep layer, mainly of adipose tissue known as the hypodermis or subcutis.
Guanine is a crystalline purine excretory product, which accumulates in specialized, peripheral cells of the digestive diverticula lying directly beneath the hypodermis (Oxford & Gillespie 1998) and has a white, blocky appearance.
The Realistic Skin Model (RSM(TM)) is capable of modeling the major layers of human skin -- stratum corneum, epidermis, dermis, and hypodermis -- independently.
to adaxial hypodermis and abaxial expansion cells; distinct outer sheath
These facts result in a longer junction line between dermis and hypodermis (dermo-hypodermal junction line), local volume increase and an uneven skin surface, with vis-ible fat nodules and irregularities on the skin surface (cellulite).
Cellulite is a skin condition that results from enlarged fat cells trapped in an inflexible network of collagen located in the hypodermis.
Skin is comprised of two main layers, held to the underlying tissue by the hypodermis, or subcutaneous fat layer, which also provides a measure of padding and insulation from temperature change.
Slimbuster L rebuilds fibers of the dermis and the hypodermis, changing all mechanically modified topography; stimulates the synthesis of collagen I and II and elastin; acts on localized fat and improves tensile strength properties of the skin.