. "An adrenergic receptor signaling pathway that contributes to an increase in frequency or rate of heart contraction. Binding of adrenalin or noradrenalin to a beta-adrenergic receptor on the surface of the signal-receiving cell results in the activation of an intracellular Gs protein. Gs activates adenylate cyclase to increase intracellular cyclic-AMP (cAMP) levels. cAMP binds directly to F-channels to allow an inward flow of sodium (known as funny current, or If current). The funny current is responsible for membrane depolarization and an increase in heart rate." . . . . . "adrenergic receptor signaling pathway involved in positive regulation of heart rate" . "activation of funny current by beta-adrenergic receptor signaling pathway" . "adenylate cyclase-activating cardiac adrenergic receptor signaling pathway" . "adrenergic receptor signalling pathway involved in positive regulation of heart rate" . "beta adrenergic receptor signaling pathway involved in positive regulation of heart rate" . "Gs-coupled adrenergic receptor signaling pathway involved in positive regulation of heart rate" . "If activation by beta-adrenergic receptor signaling pathway" . . . . . .