Thursday, June 11, 2015

The Three Primary Germ Layers

What do the primary germ layers give rise to?

Germ layer is a primary layer of cells that form during embryogenesis, each layer will eventually give rise to systems, tissues and organs as the embryo grows.

Ectoderm is the outer most layer and gives rise to the integument including hair, nails and epidermis, and the epithelial of the nose, mouth and the sense of the eye, the nervous system and inner ear)

Mesoderm is the middle layer and it forms the musculoskeletal, circulatory and most of the excretory systems. Mesoderm also develops into  gonads and the muscular and connective tissue in the digestive and respiratory system

Endoderm is the inner layer, which will eventually develop into the epithelia linings of the digestive and respiratory tracts including the lungs. It also forms the pancreas, thyroid, bladder and distal urinary tracts. Finally it will also form parts of the liver as well.


  • Ectoderm - "attracto" derm (things that attract us to others, such as cosmetic features and "intelligence")
  • Mesoderm - "means" oderm (the means of getting around as an organism, such as bones and muscle; the means of getting around in the body, such as the circulatory system; the means of really getting around, such as the gonads)
  • Endoderm - linings of "endernal" organs (the digestive and respiratory tract, and accessory organs attached to these systems)


  1. Hello Melody. I will assume "luvlody" describes you as a 'luvely' lady. But to the point... The inscription of Pre-Med Mnemonics might well be illustrated as Pre-Med 3nemonics since the "M" turned to the right is a "3" and it correlates well with your three-germ layers post as well as the 3 corticosteroids. No less, in the event that you may be unaware of the multiple "threes" in human anatomy, an excellent reference is Dr. McNulty's

    However, let us not forget to include various other "threes" references found in other subject areas covered by Michael Eck's: No less, for those interested an unorthodox philosophical approach to the "threes phenomena", you might try out my own site:

    Thanks for placing the image of the three Germ layer derivatives.

  2. Hi! Could you provide a source for the image?