Traditional and modern definition of Meridians

There is an eastern and western description of meridans.

Eastern
live force is what people see when they look at an animal and know it is living … contrasted to a stone. Anyway, this motivating force is called Chi (chee) and in traditional chinese medicine, is the focus of acupuncturists. Thousands of years ago, acupuncturists needed a system to understand health and how to diagnose problems and so described paths in the body where Chi flow. They documented points on the body where chi was prominent and then connected them with lines. These lines are called meridans.

Western
There are no lines, there are however points in the muscles and faschia that are more receptive to stimulation. These points are only connected through normal body mechanisms like muscles, nerves and circulation. However, treating these points does have an effect on the body. It increases circulation, reduces tension and draws mental attention to them.