(1) The neural crest cells migrate throughout the body and differentiate into many cell types including neurons and glial cells of the nervous system, adrenal medulla cells, pigment cells in the skin, and skeletal and connective tissues of the head. (2) The mesoderm forms the somites which differentiate depending on their position into structures like vertebrae, ribs, muscles of the rib cage, limbs, back, and dermis of the skin. (3) The endoderm develops structures of the digestive system like the pancreas, liver, and gall bladder as well as the respiratory system.

1. GERM LAYERS AND
THEIR DERIVATIVES

2. Derivatives of Germ Layers

3. Ectoderm

4. Neural Crest and its Derivatives
The neural crest cells migrate extensively to generate a prodigious
number of differentiated cell types. These cell types include
(1) the neurons and glial cells of the sensory, sympathetic, and
parasympathetic nervous systems,
(2) the epinephrine-producing (medulla) cells of the adrenal gland
(3) the pigment-containing cells of the epidermis
(4) many of the skeletal and connective tissue components of the head

6. Syndetome
(tendons)
Endothelial Cells
MESODERM

7. Although all the somites look identical, they will form
different structures at different positions along the
anterior-posterior axis.
For instance, the ribs are derived from only by the
somites forming the thoracic vertebrae.
Somites form
(1) the cartilage of the vertebrae and ribs
(2) the muscles of the rib cage, limbs, and back
(3) the dermis of the dorsal skin.

8. Differentiation of Somites

9. ENDODERM
Phayrngeal

10. Development of Pancreas, Liver and Gall Bladder

11. Development of Respiratory System