Overview of the most important biochemical pathways for cellular uptake and biological actions of the endogenous cannabinoids. Cannabinoids produce their effects by binding to specific G-protein-coupled plasma membrane receptors that can inhibit adenylate cyclase (AC); activate PKA, PI3K, AKT and MAPK; increase K+ currents and stimulate ceramide production. Intracellular degradation is achieved following their transport through the plasma membrane mediated by the endocannabinoid membrane transporters (EMT).