Somite

From Freepedia

In the developing vertebrate embryo, somites are masses of mesoderm distributed along the two sides of the neural tube and that will eventually become dermis (dermatome), skeletal muscle (myotome), and vertebrae (sclerotome). They originate from paraxial mesoderm which, towards the end of the third gestational week, becomes organized into loose masses of cells called somitomeres. Driven by changes in the expression of adhesion molecules, somitomeres compact and bud off to form the somites. Approximately 44 somites form and give rise to the bones of the face, vertebral column, associated muscles, and overlying dermis.