Layers of skin

Radiation Dosimetry. Radioactive materials cause damage to tissue by the deposition of energy via their radioactive emissions. Thus, when they are internally deposited, all emissions are important. When external, only those emissions that are capable of penetrating the outer layer of skin pose an exposure threat. The biological effects of radiation exposure and dose are generally credited to the formation of free radicals in tissue as a result of the ionization produced (17). 

Subcutaneous The deepest layer of skin, containing fatty and connective tissue that provides a cushion and insulative base for the skin and also binds the skin to the underlying tissues. 

Dru may be applied to the skin and mucous membranes using several routes topically (on the outer layers of skin), transdermally through a patch on which the drug has been implanted, or inhaled through the membranes of the upper respiratory tract. 

Salicylic acid is used to treat acne, warts, dandruff, psoriasis, and similar conditions. In the treatment of acne, it slows the shedding of skin cells in hair follicles, so they do not clog the pores and cause pimples. It also has a keratolytic effect—it causes dead skin cells to slough off— which removes the top layer of skin and clears existing pore clogs. 

In addition, data obtained from infrared, thermal, and fluorescence spectroscopic studies of the outermost layer of skin, stratum corneum (SC), and its components imply enhancer-improved permeation of solutes through the SC is associated with alterations involving the hydrocarbon chains of the SC lipid components. Data obtained from electron microscopy and x-ray diffraction reveals that the disordering of the lamellar packing is also an important mechanism for increased permeation of drugs induced by penetration enhancers (for a recent review, see Ref. 206). 

Toxic epidermal necrolysis—a life-threatening skin disorder characterized by blistering and peeling of the top layer of skin. 

Mix together 1 1/2 oz. each of ground, dried elder blossoms and peppermint leaves. Add to 2 oz. of ground oatmeal and 2 oz. corn meal. Use one oz. a week to gently scrub and remove dead layers of skin. It can also be mixed... 

Ghosh [548] used cellulose nitrate microporous filters (500 pm thick) as scaffold material to deposit octanol into the pores and then under controlled pressure conditions, displace some of the oil in the pores with water, creating a membrane with parallel oil and water pathways. This was thought to serve as a possible model for some of the properties of the outermost layer of skin, the stratum comeum. The relative proportions of the two types of channel could be controlled, and the properties of 5-10% water pore content were studied. Ibuprofen (lipophilic) and antipyr-ine (hydrophilic) were model drugs used. When the filter was filled entirely with water, the measured permeability of antipyrine was 69 (in 10 6 cm/s) when 90% of the pores were filled with octanol, the permeability decreased to 33 95% octanol content further decreased permeability to 23, and fully octanol-filled filters indicated 0.9 as the permeability. 

Alpha hydroxy acids (AHAs) are water-soluble substances and thereby penetrate the outermost epidermal skin layers. In contrast, beta hydroxy acids (BHAs) are lipid (fat) soluble and are capable of penetrating to the underlying layers of skin (the dermis) located 1-5 mm below the surface of the skinJ2 Most AHAs are derived from plant materials and marine sources. Commonly used AHAs include malic acid (found in apples), ascorbic acid (a common ingredient in numerous fruits), glycolic acid (a constituent of sugar cane), lactic acid (a component of milk), citric acid (naturally abundant in citrus fruits), and tartatic acid (found in red wine). A common BHA is salicylic acid (an ingredient in aspirin). 

The hazard of a mixture of mustard and Lewisite (HL) on the eyes and skin, or vapor in the eyes or respiratory tract, is immediate. Within an hour, edema of the conjunctivae and lids begin and soon results in eye closure. Any casualty experiences serious pain seconds after contact with HL liquid, but such extreme pain makes the injured person decontaminate at once. Rapid decontamination is the sole manner to avoid severe burns since after a few minutes of contact with a mixture of mustard and Lewisite, the upper layer of skin will die and appear gray, painful erythema will be apparent shortly thereafter, and... 

When I got to Seattle, in 93, I was pretty sick. I had hives all over my body and eczema all over my hands. It was painful, especially in massage school where my hands were in contact with water all the time. They used to hurt so bad that I had to keep socks on them, and when I was waitressing I d have to get people to wipe the tables for me. If I put rubber gloves on I reacted to the rubber. Before I knew any better, I was using cortisone and lost a layer of skin on my hands. 

Phenol can have beneficial effects when used for medical reasons. It is an antiseptic (kills germs) when applied to the skin in small amounts and may have antiseptic properties when gargled as a mouthwash. It is an anesthetic (relieves pain) and is a component of certain sore-throat lozenges and throat sprays or gargles. Small amounts of phenol in water have been injected into nerve tissue to lessen pain associated with certain nerve disorders. Phenol destroys the outer layers of skin if allowed to remain in contact with skin, and small amounts of... 

Bohr s idea led to the comparison that likened the structure of the atom to the structure of an onion. The outer layers of skin on an onion are the shells where the electrons exist. 

The most superficial layer of skin is the stratum comeum (SC), which consists of terminally differentiated keratinocytes (comeocytes) that originate from actively proliferating keratinocytes in lower epidermis (basale, spinosum, and granulosum cells), and contain a lamellar lipid layer secreted from lamellar bodies (Fig. 7a). Flydration of the SC is an important determinant of skin appearance and physical properties, and depends on a number of factors including the external humidity, and its structure, lipid/protein composition, barrier properties, and concentration of water-retaining osmolytes (natural moisturizing factors, NMFs) including free amino acids, ions, and other small solutes. 

Parenteral administration This route is applicable for drugs which are inactivated by gastrointestinal tract or absorption is poor when given orally or there is a urgency for fast response in small dose. Intramuscular, intravenous, or subcutaneous routes are commonly used. The intravenous injection (in aqueous solution) is introduced directly into the vein by which a rapid response is produced. The subcutaneous injection are given through the layer of skin, while intramuscular injection, introduced through the skin layer deep into the muscle. The nature of intramuscular injection may be in aqueous or oily solution/suspension form. The aqueous solution will be rapidly absorbed as compared to oily solution or suspension. So, the rate of absorption is dependent on the nature of the preparation. 

For the home winemaker, the separation is facilitated if a cylindrical stainless steel screen closed at the bottom and long enough to extend from the top level of the cap to the bottom of the fermentation vessel is obtained. The screen is pushed down through the layer of skins until the screen bottom is in contact with the bottom of the fermenter. The wine is then siphoned from the inside of the screen into the containers in which the fermentation will finish. When no more free run wine can be obtained, the residual skins may be pressed to augment the yield considerably. Excessive pressure is to be avoided in this step lest the press wine be overly astringent and bitter. The free run wine should be kept separate from the press wine until the fermentations are finished. Tasting at this time will dictate whether the two can be blended without impairment of quality or whether the press wine is to be kept as a second quality wine. 

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