The neurotransmitter agent that is normally released in the SA node of the hea in response to increased blood pressure is: (A) Acetylcholine, (B) Dopamine, (C) Adrenaline, (D) Noradrenaline
Answer is A. Ref-KDT 6/e p107 Whenever blood pressure increases there is reflex stimulation of baroreceptors. The release ACh and depresses the hea