The brain produces neurotransmitters called catecholamines, which have different functions, both in the CNS and sympathetic limb. Norepinephrine, for example, is a neurotransmitter that acts on smooth muscles, causing them to contract and relax. Dopamine, meanwhile, is a neurotransmitter found in the kidney and autonomic ganglia. It is also a neurohumoral agent released into the […]