How does angiogenesis differ from vasculogenesis?

Angiogenesis is the growth of new capillaries from pre-existing blood vessels. The primary function of angiogenesis is to repair damage caused by cellular injury and wounds. Vasculogenesis is the in situ differentiation and growth of blood vessels from mesoderm derived hemangioblasts, leading to the formation of the circulatory system. In contrast to vasculogenesis, there are two different mechanisms involved in angiogenesis: endothelial sprouting and introspective microvascular growth (IMG). Endothelial sprouting is based on endothelial cell migration, tube formation, and proliferation. IMG divides existing vessel lumens via formation and insertion of tissue folds and columns of interstitial tissue into the lumen. Vasculogenesis also takes place during embryonic development, while angiogenesis occurs throughout life.