ABSTRACT
Tissue growth and development is ideally subserved by an effective and responsive blood delivery system, one that functions to continuously adapt to the metabolic needs of its respectively dependent organs. With respect to oxygen demand, the vasculature must optimize blood flow, surface area, and structural plasticity to accommodate these varied requirements. Tissue neovascularization, both under physiological conditions and in pathology, is a phenomenon that occurs via three distinct modes of vessel growth. While the entire range of vessel growth events is often collectively referred to as angiogenesis, this process exclusively encompasses vessel growth that originates directly from pre-existing vasculature. Vascular responsiveness to a tissue’s metabolic demands is perhaps most critically dependent upon oxygen delivery. Heightened metabolic needs and increased distances from a vascular bed therefore require an enhanced rate of blood flow. While autoregulated vasodilation often partially diminishes an oxygen deficit, there are limits to this compensatory response.
