Limb Development

**Semantic type:** Organ or Tissue Function

**Definition:** Interdependent positional signaling by the apical ectodermal ridge, the posterior mesenchyme zone of polarizing activity, and the non ridge ectoderm coordinate limb bud outgrowth and patterning, Limb Development, by migrated lateral plate mesoderm and somite cells. Proximal-distal differentiating mesenchymal cells condense to form the limb skeletal primordia.