According to Marcondes (2003), in neonatos, the set free indirect bilirubin in the sanguineous chain is lipossolvel and, so that it is carried, the albumen is leagued to it, forming the complex bilirubin-albumen, however of reversible form. When reaching the membrane of the hepatcito the bilirubin of the complex is dislocated through the process of diffusion by means of a called carreador ligandina Y for the interior of the hepatcito, leaguing itself ace soluble proteins. To be excretada indirect bilirubin it must be conjugated the acid glicurnico and catalyzed by the enzyme glicuroniltransferase giving to origin direct bilirubin (BD). More info: The Florey Institute. Soon after, the bilirubin quickly is excretada for bile for the heptica cell. The reabsoro of bilirubin in the heptica circulation entero- in the RN is great, due to absence of the bacterial flora in the intestine, not having reduction. The intestine of the RN presents the enzyme beta-glicuronidase that hidrolisa the direct bilirubin in bilirubin not? conjugated, that it is absorbed, raising the bilirubin overload for the immature liver. According to Tamez and Silva (2002), one of the characteristics of the neonatal jaundice is the yellowish coloration of the skin, of the mucosae and escleras.

It is a sufficiently common clinical situation in children, decurrent of the indirect hiperbilirrubinemia being able to be physiological. Case if to persist or to exist the suspicion of to be pathological after the first days of birth the RN will be submitted the fototerapia. 3.2.2 Physiological jaundice In accordance with Zago (2002); It hisses (2008), the physiological jaundice is characterized by the increase of the indirect bilirubin levels, reaching a tax of 7mg/dl next to 3 day to life. According to SEGRE (2002), the possible involved mechanisms in the IF are: 1. It offers increased of bilirubin for the heptica cell the greater cost volume of hemcias circulantes/kg of weight, life measured short more of the hemcias and increase of the entero-heptica circulation of bilirubin; 2.