A meshwork of mesoderm-derived undifferentiated loose connective tissue in the embryo, and thus sometimes referred to mesenchymal connective tissue. Derived mainly mesoderm, some of it has its origins in other germ layers, as well as from ectoderm of the neural crest. It consists of a gelatinous ground substance that is made of proteins and water. Given Its gelatinous nature, it protects the cells and reticular fibers within it. The importance of mesenchyme for embryonic development is evident from the fact that it gives rise to bone cartilage, the circulatory system and the lymphatic system in the fully developed fetus.
See Apical epidermal ridge (AER), Chondrification, Dorsal plate in limb bud, Ectoderm, Embryo, Endochondral ossification, Epithelium, Germinal (or germ) layers, Histology, Limb bud, Mesoderm, Neural crest, Neurulation, Ossification, Pharyngeal arches, Ventral plate in lim bud