epidermis


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epidermis

 [ep″ĭ-der´mis] (pl. epider´mides) (Gr.)
the outermost and nonvascular layer of the skin, derived from the embryonic ectoderm, varying in thickness from 0.07 to 1.4 mm. On the palmar and plantar surfaces it comprises, from within outward, five layers: (1) basal layer (stratum basale), composed of columnar cells arranged perpendicularly; (2) prickle-cell or spinous layer (stratum spinosum), composed of flattened polyhedral cells with short processes or spines; (3) granular layer (stratum granulosum), composed of flattened granular cells; (4) clear layer (stratum lucidum), composed of several layers of clear, transparent cells in which the nuclei are indistinct or absent; and (5) horny layer (stratum corneum), composed of flattened, cornified, non-nucleated cells. In the epidermis of the general body surface, the clear layer is usually absent. adj., adj epider´mal, epider´mic.
Section of epidermis. From Dorland's, 2000.

ep·i·der·mis

, pl.

ep·i·derm·i·des

(ep'i-dĕrm'is, -derm'i-dēz), [TA]
1. The superficial epithelial portion of the skin (cutis). The thick epidermis of the palms and soles contains the following strata, from the surface: stratum corneum (keratin layer), stratum lucidum (clear layer), stratum granulosum (granular layer), stratum spinosum (prickle cell layer), and stratum basale (basal cell layer); in other parts of the body, the stratum lucidum and stratum granulosum may be absent.
2. In botany, the outermost layer of cells in leaves and the young parts of plants.
Synonym(s): cuticle (3) , cuticula (2) , epiderm, epiderma
[G. epidermis, the outer skin, fr. epi, on, + derma, skin]

epidermis

(ĕp′ĭ-dûr′mĭs)
n.
1. The outer, protective, nonvascular layer of the skin of vertebrates, covering the dermis.
2. An integument or outer layer of various invertebrates.
3. The outermost layer of cells covering the leaves and young parts of a plant.

ep′i·der′mal (-məl), ep′i·der′mic adj.

ep·i·der·mis

, pl. epidermides (epi-dĕrmis, -mi-dēz)
1. The superficial epithelial portion of the skin (cutis). The epidermis of the palms and soles has the following strata: stratum corneum (horny layer), stratum lucidum (clear layer), stratum granulosum (granular layer), stratum spinosum (prickle cell layer), and stratum basale (basal cell layer); in other parts of the body, the stratum lucidum may be absent.
2. botany The outermost layer of cells in leaves and the young parts of plants.
Synonym(s): cuticle (3) , cuticula (2) .
[G. epidermis, the outer skin, fr. epi, on, + derma, skin]

epidermis

The structurally simple outermost layer of the skin, containing no nerves, blood vessels, or hair follicles, and acting as a rapidly replaceable surface. The deepest layer of the epidermis is the basal cell layer. Above this is the ‘prickle cell’ layer. The epidermis is ‘stratified’, the layers of cells becoming flatter towards the surface. The outermost cells of the epidermis are dead and are continuously shed.

epidermis

  1. (in plants) the thin tissue, usually one cell thick, that surrounds young roots, stems and leaves. In stems and leaves the epidermal cells secrete a CUTICLE (1), in roots they do not. In older roots and stems the epidermis is often replaced by CORK tissue.
  2. (in animals) the outer layer of the skin derived from embryonic ECTODERM. In vertebrates, the epidermal layer is usually made up of stratified EPITHELIUM with an outer layer of dead cells which become ‘keratinized’ (see KERATIN forming a protective layer. The invertebrate epidermis is normally one cell thick and often forms a protective cuticle.

Epidermis

The outer layer of skin, consisting of a layer of dead cells that perform a protective function and a second layer of dividing cells.

ep·i·der·mis

, pl. epidermides (epi-dĕrmis, -mi-dēz)
[TA] The superficial epithelial portion of the skin (cutis).
[G. epidermis, the outer skin, fr. epi, on, + derma, skin]
References in periodicals archive ?
Among the claudins expressed in the epidermis, claudin-1 is most critical for the formation and function of TJs, as confirmed in claudin-1knockout mice, which showed severe dehydration and death soon after birth without modulating SC formation [60].
Microscopic examination ofthe epidermis ofthe leaves revealed opened stomatal pores.
Vanable Jr., "The glabrous epidermis of cavies contains a powerful battery," The American Journal of Physiology, vol.
Although Staphylococcus epidermidis and Staphylococcus aureus belong to the Staphylococcus and are both Gram-positive bacteria, the survival rate of Staphylococcus epidermis was lower than that of Staphylococcus aureus after being irradiated by the same UV light parameters.
Anomocytic stoma is large, dense and two epidermis cells in both epiderma (Fig.
Thirteen cases were histologically diagnosed and 9 cases showed atrophic epidermis, two cases intraneural inflammation, 3 cases perivascular and peri-appendage inflammation.
Immune functions of the skin are augmented by the presence of symbiotic micro-organisms (including bacteria, fungi, viruses and even mites) nestled in the epidermis and occupying hair and gland shafts.
Structure of the reconstructed human epidermis was similar to human epidermis
The Effect of Topical SOP on the Proportion of Apoptotic Cells in the Epidermis after UVB Irradiation.
To facilitate the penetration into the epidermis one should avoid excipients having partition coefficients similar to the one of the active: if so, the active could well be trapped inside the formula layered onto the surface and not be released into the stratum corneum.
Regeneration of skin cells and repair of damages to the skin begins with the most profound portion of the epidermis -- the stratum basale.