Articles On Epidermis

Skin is that the largest organ within the body and covers the body's entire external surface. it's made from three layers, the epidermis, dermis, and therefore the hypodermis, all three of which vary significantly in their anatomy and performance . The skin's structure is formed from an intricate network that is the body’s initial barrier against pathogens, UV light, and chemicals, and mechanical injury. It also regulates temperature and therefore the amount of water released into the environment. this text discusses the relevant anatomical structures of the skin’s epidermal layer, its structure, function, embryology, vascular supply, innervation, surgical considerations, and clinical relevance. The skin functions as a barrier protecting the body from dehydration and environmental insults. During this journey, keratinocytes undergo a series of biochemical and morphological changes that end in the formation of the varied layers of the epidermis. The concept that mammalian epidermis. the subsequent empirical measurements were used: 75,346 nucleated epidermal cells per 2mm, 1394 Langerhans cells per 2mm, 1999 melanocytes per 2mm, 16 (SC) layers, 900-2μm corneocyte area , 17,778 corneocytes per 2mm, 14-d (SC) turnover time, and 93,124 per 2mm total epidermal cells. Given these empirical data: (1) the amount of corneocytes may be a mean proportional between the sum of the Langerhans cell + melanocyte populations and therefore the number of epidermal cells, 3393/17,778–17,778/93,124; (2) the ratio of nucleated epidermal cells over corneocytes is proportional, 75,346/17,778∼phi3; (3) assuming similar 14-d turnover for the (SC) and Malpighian epidermis, the amount of corneocytes results from subtraction of a cellular fraction adequate to ∼2/phi2×the number of living cells, 75,436 – (2/phi2×75,346)∼17,778; and (4) if total epidermal turnover time equals (SC) turnover time×the ratio of living or dead cells, then compartmental turnover times are unequal (14 d for (SC) to 45.3 d for nucleated epidermis ∼1/2phi) and cellular replacement rates are 52.9 corneocytes/69.3 keratinocytes per mm2 per h ∼2/phi2. These empirically derived equivalences provide logic mathematical support for the presence of functional epidermal units in human skin. Validation of a proportional unit architecture in human epidermis are going to be important for tissue engineering of skin and therefore the design of instruments for skin measurement.