The origin of organs: The formation of the epidermis. Dissemination 78th
The epidermis is the outermost skin layer that originates at the time of embryo neurulation, from the outer cell layer that surround it. Is initially formed of a single layer of cells that evolves immediately a stratified bilamellar body composed of an outer layer (stratum corneum) and an inner layer composed of two laminae (granular lamina, the outermost of the interior, and basal lamina, the deepest).
This structure is intended to maintain the stability of the organism (homeostasis) against a hostile external environment for temperature, low humidity, radiation and chemical and microbial agents. Cells constituting the granular layer are called keratinocytes. Its mission is to form an outer keratin layer for which lose their nuclei and become flattened.
This process is genetically governed by biosynthesis of three growth factors of protean character:
1. Alpha factor, stimulating cell division of the basal lamina to produce keratocytes.
2. Growth factor of keratocytes.
3. Differentiation factor of keratocytes.
Some pronutrients factors can improve meta-genetically the synthesis of these growth factors and differentiation of keratinocytes and improve skin physiology.
It is considered that travel to the outside of keratinocyte normally lasts, 7 weeks: one for production in the basal lamina, two for differentiation into granular sheet and four through the stratum corneum. Once arrived to the outside keratocyte is eliminated, considering that this elimination produce 1 mg of desquamation per m2 of skin and day.