The neuropeptide '''Acetylcholine (Ach)''' is primarily involved in skeletal muscle movement within the sympathetic nervous system and visceral movements as part of the parasympathetic nervous system. '''Nitrous oxide''' is involved in enlargement of the genital organs leading to erection. | The neuropeptide '''Acetylcholine (Ach)''' is primarily involved in skeletal muscle movement within the sympathetic nervous system and visceral movements as part of the parasympathetic nervous system. '''Nitrous oxide''' is involved in enlargement of the genital organs leading to erection. |