The epidermis is a layer of cells on the exterior of stems and leaves as well as other plant organs. This is a protective layer that keeps out bacterial and fungal spores as well as sealing the plant organ from loss of water. Cutin, secreted by the epidermal cell, is a waxy material that allows the epidermal cell to be very effective in preventing water loss. In cross section, the epidermis looks like small bricks. Looking at epidermal cells from the top down, they have the appearance of a jigsaw puzzle pieces. DIAGRAMS: Stomata / Root Anatomy / Woody Stem / Equisetum Ovary Position PHOTOS: Tilia Stem Cross Section (6-year) Tilia Stem Cross Section (3-year) Monocot Stem Cross Section / Monocot Stem Cross Section Leaf Cross Section / Leaf Cross Section Root Cross Section / Root Cross Section Fucus / Fucus / Fucus / Fucus / Fucus Puccinia / Puccinia Anthoceros Moss Stem Cross Section Moss Leaf Cross Section
The outermost layer of the skin. Melanocytes, basal cells, and squamous cells are found in the epidermis. Overexposure of the epidermis to ultraviolet rays from the sun can lead to skin cancer. See also: Skin-Cancer
The outer layers of skin.() Free radicals: Unstable, scavenger cells that cause damage to healthy cells. They can come from the sun, pollution, stress, cigarettes, alcohol, and other outside factors. The best line of defense is using antioxidant vitamins such as A, C and E which help to neutralize free radicals. ()
The outermost layer of the skin. The epidermis contains no nerves or blood vessels, so the epidermis alone is incapable of sensation or bleeding. Composed of a protective outer layer of nonliving keratin-derived scale cells, the epidermis acts as an envelope or seal against the environment and exerts some control on the amount of moisture lost to the environment. The epidermis contains keratinocytes (cells that make keratin) and melanocytes (cells that make pigment), as well as other specialized cells.
The abnormally increasing pigmentaciÃ³n of new to the pigmentaciÃ³n abnormally diminished of the cover, being from the diminished production del melanin (dark pigment) of new to the protein of the cover To that it is in hair, the nails and the outer skin leans.
The epidermis is the protective outer layer of the skin. It is in a constant state of renewal, shedding older cells and replacing them with newer cells. Basal cells in the lower level of the epidermis move towards the surface. These basal cells divide and become squamous cells, which get flatter and harder as they move towards the surface. Eventually squamous cells rest on the surface, only to be shed and replaced again over a twenty-eight day cycle. The epidermis also contains melanocyctes that produce and distribute melanin, the pigment that gives skin and hair it's color. Melanin ranges from minimal in very fair skin to dense in black skin. Melanin helps to protect the skin against UV-related damage.
the outermost layer of the skin that consistently regenerates itself. The top level of cells are dead skin cells and underneath are living cells that push their way up to the surface, then die and flake off.
1. The outermost layer of skin consisting of several layers of epithelial cells&emdash;notably, keratinocytes&emdash;and, in the inner layer of the epidermis, basal cells and melanocytes. 2. The outer layer of cells in the plant body, often covered by a waxy cuticle.
The epidermis is the upper most layer of skin. It is attached to the bottom of the nail plate and is ridged with tiny 'rails' that run in the same direction as the dermis grooves. The effect is much like a train riding on its tracks as it moves forward.
Uppermost layer of the skin. The epidermis is highly cellular and divided into layers: the basal (bottom) layer that produces new cells and contains melanocytes or pigment-producing cells; a thick prickle cell layer; the granular cell layer and the stratum corneum or top layer.
Abnormally increased pigmentation. back to top Abnormally diminished pigmentation, resulting from diminished melanin (dark pigment) production. A protein which is found in hair, nails and the outermost skin layer.
The upper covering layer of the body, and with the underlying dermis, is referred to as the skin. The upper-most part of the epidermis is called the stratum corneum, composed of dead cells. Immediately below that is the area of living epidermal cells. It is within this layer that the various pathologic changes of pemphigus take place. Superficial separation is seen more in pemphigus foliaceus while slightly deeper separation is seen in pemphigus vulgaris. In bullous pemphigoid the separation occurs below the epidermis - between the epidermis and dermis.
The outer layer of cells of all parts of a young plant and of some parts of older plants, such as leaves and fruits. These cells are usually covered with a waxy substance, called the cuticle, that minimizes water loss.
the outermost (external) layer of the skin. The principle cell of the epidermis is the keratinocyte. The epidermis is subdivided into 5 layers; stratum germinativum, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum (outermost layer).
Top layer of the skin, its upper part being made of horny material (stratum corneum). It prevents the body from dehydrating and protects it against environmental factors. The epidermis also contains other cells, such as basal cells and Merkel cells. Merkel cells are responsible for our sense of touch.
Roles: Protecting the organism from external threat through the production in its upper section of a protective stratum corneum which is about 0.2 mm thick. A barrier against UV radiation. An immunological barrier (pathogenic bacteria, viruses, etc.) barrier against chemical liquids and substances. Protection from scratches, scrapes and stings. The epidermis is composed of 4 layers of cells with specific morphologies and metabolism. The horny layer (10 to 30 layers of cells). The granule cell (3 to 4 layers of cells). The spiny layer (5 to 6 layers of cells). The basal layer (a single leyer of cells). Thickness: 0.2 mm (eyelid) to 1 mm (soles of the feet).
the external cellular layer of a multicellular organism. Invertebrate epidermis is often one cell thick and may secrete a waxy cuticle. Vertebrate epidermis is the multiple cell layer of the skin. the outermost cell layer of a multicellular organism, an example is the skin of vertebrates.
The top layer of the skin, which acts as your body's natural suit of armor. The epidermis is made up of corneocytes (the outermost layer of dead skin cells), melanocytes (which produce melanin, the substance that gives your skin its color), and Langerhan cells (which work with the immune system to help you fight off disease).
The outer layer of cells. A layer of primary tissue in higher plants that is commonly one cell thick, often cutinized on its outer surface, and continuous in young plants except over the stomata. The epidermis provides protection to the underlying parts against mechanical injury and desiccation and is largely replaced in older plants except on leaves and herbaceous stems.
Gk, epi, on or upon + derma, skin], the superficial, avascular, layers of the skin, made up of an outer, dead cornified portion and a deeper, living, cellular portion. Altogether, these layers are between 0.5 to 1.1 mm
The outer section of the skin, which separates the external environment from the dermis. Cosmetic products can't penetrate any deeper than the epidermis's outermost layer, the stratum corneum. In terms of dry skin and moisturizing, the stratum corneum is where all the action is.
The outer layer of the skin, it protects the body from the sun, from bacterial invasion, and from dehydration. The epidermis forms the first immune defense for outside invaders, so skin health is essential to support this defense.
The outer, nonvascular, nonsensitive layer of the skin which contains no nerves or blood vessels. The epidermis acts as a seal against the environment while exerting some control over the amount of moisture lost to the environment.
The outer layer of the skin which provides protection against the elements. The epidermis replaces itself about every 45-75 days and is comprised of four layers: stratum corneum, granular layer, spinous layer and basal layer. The stratum corneum is the outer most layer and is primarily made up of keratin proteins. The basal layer is where the cells grow and divide.
The epidermis (pluralized either epidermises or sometimes epidermes) is the outer single-layered group of cells covering a plant, especially the leaf and young tissues of a vascular plant including stems and roots. Epidermis and periderm are the dermal tissues in vascular plants. The epidermis forms the boundary between the plant and the external world.