A number of different cell types contribute to the cellular architecture of adipose tissue. While the adipocyte is functionally making important contributions to systemic metabolic homeostatsis, several additional cell types contribute a supportive role to bestow maximal flexibility on the tissue with respect to many biosynthetic and catabolic processes, depending on the metabolic state. These cells include vascular endothelial cells, a host of immune cells as well as adipocyte precursor cells and fibroblasts. Combined, these cell types give rise to a tissue with remarkable flexibility with respect to expansion and contraction, while optimizing the ability of the tissue to act as an endocrine organ through the release of many protein factors, critically influencing systemic lipid homeostasis, as well as biochemically contributing many metabolites. Using an example from each of these categories will be discussed – adiponectin as a key adipokine, sphingolipids as critical mediators of insulin sensitivity and uridine as an important metabolite contributed by the adipocyte to the systemic pool.