Is decreased heart rate caused by parasympathetic division of ans?

Yes, a decreased heart rate is primarily influenced by the parasympathetic division of the autonomic nervous system (ANS). The vagus nerve, a key component of the parasympathetic system, releases acetylcholine, which slows down the heart rate by decreasing the excitability of the sinoatrial node. This process helps to promote a state of rest and relaxation in the body.