Atlas histologico del desarrollo embrionario –estadios de witschi– de la rata albina wistar (rattus norvegicus).

The rat, after the mouse is the most commonly used experimental animal in biomedical research, especially in studies that include some component of basic health sciences. The albino rats of Wistar strain belonging to the species Rattus norvegicus (brown rat) was the first rat strain developed to serve as an experimental model organism, however, and given their living conditions in the animal facility (power, exposure to light, moisture, temperature, etc..) and their biological behavior (length of pregnancy, prenatal development, postnatal growth, size, weight, etc..), it is possible to have a local registry and updated standard could ascertain the embryonic development correlated with gestational age, since in the literature it has been shown that biomodel biological conditions can be affected by factors generated in the environment where it is produced and raised. That is why this research project is to describe the embryonic development of the Wistar albino rat (Rattus norvegicus) through three histological (hematoxylin-eosin, PaS and Masson trichrome) based on Witschi stadiums. Talk of the correlation between the embryonic development of the different systems (central nervous, cardiovascular, respiratory, musculoskeletal, digestive, endocrine and genitourinary) on gestational time Wistar albino rats gestational will reveal the chronology and development (histogenesis and organogenesis) of different levels of organization (tissues, organs and systems) Wistar rat of a local animal facility Cali (Colombia), in such a way as to create a standard which will enable it to meet the biomodel researchers from the point of view of developmental biology. Therefore, the results obtained, it is intended to develop a histological atlas of embryonic development of the Wistar rat as a reference to researchers using this biomodel in experimental studies, contributing to the standardization of the methodology and minimizing the margin of mistake.