EMBRYOLOGY

1.      Embryonic development;
      ·         is triggered by fertilisation.
      ·         can be divided into three main stages:
             o   Cleavage
             o   Gastrulation,
             o   Organogenesis
 
2.      Cleavage:
      ·         division of the zygote
      ·         into daughter cells.
      ·         embryo (at the end of this stage) = blastula

 

3.      Gastrulation:
      ·         arrangement of embryonic cells
      ·         into three germ layers (ectoderm, mesoderm +  endoderm).
      ·          embryo (at the end of this stage) = gastrula.

4.      Organogenesis:
      ·         formation of organs + organ systems.
      ·         each germ layer àgives rise to different organ systems.