Reasons to Smile IX:
Neurotransmitters are chemical substances that transmit nerve impulses across the space between nerve cells or synapses. Two of these naturally occurring drugs in the human body are endorphins and serotonin. Endorphins can serve as natural pain killers and serotonin is related to feelings of happiness and well being. Studies have shown that smiling can stimulate the release of these natural chemicals in the body resulting in good feelings.