Dual excitatory channels in the sinus node.
D000109:Acetylcholine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D006168:Guinea Pigs; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D012849:Sinoatrial Node / Q000187:drug effects / Q000502:physiology*; D012964:Sodium / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D013779:Tetrodotoxin; D012964:Sodium; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium