The Theory of Keratinization

Abstract

Abstract: This study was carried out on eight of Awassi ewes in estrus during which keratinization can occur in the animal farm of college of veterinary medicine, Baghdad university in June 2006. In order to study the process of keratinization histologically, samples of vaginal smears were taken and stained by methylene blue. The present study recognized five stages of keratinization namely (stage of mitosis, stage of cellular transformation, stage of cellular adhesion, stage of endogenous bacterial invasion and stage of sloughing), during which the cells undergo a series of transformations in shape, size, colour and cornification. The study found also that the cells were transformed from small spherical basophilic shape to large polygonal acidophilic shape as the polygonal shape was suitable in hidden the interstitial spaces between the cells, when these cells try to building a compact sheet or packet which act as a defensive barrier to protect the internal environment against the external environment, finally the endogenous bacteria metabolize the glycogen into lactic acid which decrease the pH of the vagina and protect it from the pathogenic bacteria. Then these attacked cells start to exfoliated so that, we can regard the process of keratinization as a defensive mechanism in the vagina.