Gastrulation is an early phase of embryogenesis whereby a single-layered blastula differentiates into three germ layers

  • The organisation of cell layers occurs by different mechanisms in different types of animals
  • The end result in all cases is a trilaminar (three layered) mass of cells called a gastrula
  • Gastrulation precedes further cellular differentiation by processes such as neurulation

Types of Cell Movements During Gastrulation


Germ Layers

Gastrulation results in the production of three germ layers – ectoderm (outer), mesoderm (middle) and endoderm (inner)

  • The ectoderm will form the nervous system (via neurulation) and outer surfaces such as skin, pigment cells and hair cells
  • The mesoderm will form the majority of body organs, including muscle, blood vessels, kidney, heart and skeleton
  • The endoderm will form the respiratory and digestive tracts, as well as associated organs such as the liver and pancreas

Differentiation of the Three Germ Layers

germ layers