RESUMO
Se presentan los resultados de 70 cráneos de embriones y fetos de diferentes edades, los cuales están comprendidos entre la semana 8 y la 38 de la vida intrauterina. Con el objeto de teñir las sales de calcio de los núcleos de osificación se utilizó Alizarina roja. Se revisó el proceso de osificación del Occipital y se encontró que el mismo se inicia en la 8va. semana de la vida intrauterina, se hacen consideraciones sobre las variaciones que presentan el Occipital en su osificación
Assuntos
Humanos , Masculino , Feminino , Calcificação Fisiológica , Estruturas Embrionárias , Desenvolvimento Fetal , Osso Occipital/anatomia & histologia , OsteogêneseRESUMO
Forty seven skeletons belonging to human fetuses, whose age ranged from eight to thirty eight weeks, were studied in order to establish the beginning of ossification in the bones. Red alizarin was employed in order to stain bone calcifications. Our observations agree with other authors considered as references nonetheless, we also have found differences among the beginning and the sequence of development of some of the primary centers of ossification in the fetal foot. The appearance of the ossification centers was as follows: 1) the five metatarsals: 9th. week; 2) distal phalange first digit; 11th. week; 3) a) proximal phalange 1, 2, 3, 4, 5 digits: 12th. week, b) distal phalange 2, 3, 4, 5 digits: 12th. week; 4) middle phalange second digit: 17th. week; 5) a) middle phalange fourth digit: 18th. week, b) middle phalange third digit: 18th. week, y 6) middle phalange fifth digit: 21th. week.