Carnegie stages

Carnegie Stages refer to a series of developmental milestones in the early stages of human embryonic development. Established by the Carnegie Institution in the early 20th century, these stages count from fertilization onward and detail the formation and differentiation of the embryo. There are 23 stages, starting with a single fertilized egg and progressing through various forms, including the implantation and formation of essential structures such as the heart and nervous system. Understanding these stages helps scientists study developmental biology, genetics, and related medical fields.