The epidermal layer that contains a large quantity of keratin is known as the stratum corneum. This layer is the outermost layer of the epidermis and is responsible for providing protection and waterproofing to the skin.
The stratum corneum is the outermost layer of the epidermis, composed of large, flat, polyhedral, plate-like envelopes filled with keratin, which is made up of dead cells that have migrated up from the stratum granulosum.[1] From the Latin for horned layer, this skin layer is composed mainly of dead cells that lack nuclei. As these dead cells slough off on the surface in the thin air-filled stratum disjunctum, they are continuously replaced by new cells from the stratum germinativum (basale). In the human forearm, for example, about 1300 cells/cm2/hr are shed. This outer layer that is sloughed off is also known as the stratum dysjunctum.Cells of the stratum corneal contain keratin, a protein that helps keep the skin hydrated by preventing water evaporation. These cells can also absorb water, further aiding in hydration, and explaining why humans and other animals experience wrinkling of the skin on the fingers and toes ("pruning") when immersed in water for prolonged periods. In addition, this layer is responsible for the "spring back" or stretchy properties of skin. A weak glutenous protein bond pulls the skin back to its natural shape.The thickness of the stratum corneum varies according to the amount of protection and/or grip required by a region of the body. For example, the hands are typically used to grasp objects, requiring the palms to be covered with a thick stratum corneum. In a similar manner, the sole of the foot is prone to injury, and so it is protected with a thick stratum corneum layer. In general, the stratum corneum contains 15 to 20 layers of dead cells. The stratum corneum has a thickness between 10 and 40 μm.In reptiles, the stratum corneum is permanent, and is replaced only during times of rapid growth, in a process called ecdysis or moulting. The stratum corneum in reptiles contains beta-keratin, which provides a much more rigid skin layer.
The epidermis is composed of 4-5 layers depending on the region of skin being considered. Those layers in descending order are the cornified layer (stratum corneum), clear/translucent layer found only on the palms and soles (stratum lucidum), granular layer (stratum granulosum), spinous layer (stratum spinosum), and basal/germinal layer (stratum basale/germinativum). The term Malpighian layer (stratum malpighi) is usually defined as both the basal and spinosum layers as a unitThe Layers of the Epidermis are.1- Stratum Corneum ( Most Superficial )2- Stratum Granulosum3- Stratus Spinosum4- Stratum Basale or Basal Layer ( Deepest Layer )* Stratum Corneum = keratinized,dead,flattened scale-like and non-nucleated cells which are continuously shed as flake-like residue. * Stratum Lucidum = thin,clean layers found only in epidermis of the lips,palms and soles. * Stratum Granulosum = one or more layers of granular cells that contain fiber ang keratin and shriveled nuclei. * Stratum Spinosum =spiny layer, several stratified layer of cells in contact with centrally located, large oral nuclei and spine like process. * Stratum Germinativum = basal layer, simple layer of cuboidal cells in contact with the epidermis.From deepest to superficial: Stratum germinativum (also called "stratum basale"), stratum spinosum, stratum granulosum, stratum lucidum (palms & soles), and stratum corneum, the outermost layer that is composed of dead skin cells.
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The stomach contains large amounts of hydrochloric acid, which helps in the digestion of food by breaking down proteins and killing harmful bacteria.
A hard, coarse plutonic rock that contains large amounts of olivine.
The skin contains three main layers of tissue: the epidermis (outermost layer), the dermis (middle layer), and the hypodermis (innermost layer). Each layer plays a different role in protecting and supporting the body.
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Sebum, a natural oil produced by the sebaceous glands in the skin, helps make the skin water-resistant. It forms a thin layer on the skin's surface, preventing water from easily penetrating into the skin. Additionally, the outermost layer of the skin, called the stratum corneum, also plays a role in providing water resistance.
The soil contains large amounts of oxygen.
Dark chocolate (60% cacao or higher).