Bookshelf

Vasculogenesis and angiogenesis. Vasculogenesis involves the formation of hemangioblastic blood islands and the construction of capillary networks from them. Angiogenesis involves the formation of new blood vessels by remodeling and building on older ones. Angiogenesis finishes the circulatory connections begun by vasculogenesis and builds arteries and veins from the capillaries. In this diagram, the major paracrine factors involved in each step are shown boxed, and their receptors (on the vessel-forming cells) are shown beneath them. (After Hanahan 1997; Risau 1997.)