Animal acupuncture. Bronze teaching model of a horse showing a traditional acupuncture chart. Meridians (lines) and points are mapped out across the skin surface. The meridians relate to channels of energy within the body. Imbalances in the flow of energy are thought to cause pain and disease. The insertion of needles at precise points (marked by the dots) is thought to stimulate energy flow and alleviate the problem. Acupuncture may work by inducing the production of endorphins (natural painkillers) within the central nervous system, or by stimulating the nerves to inhibit the original pain. Photographed in Taichung Science Museum, Taiwan.