The channels and collateral courses are longitudinal and horizontal passages of liquid and gas between fascia along channels and collaterals,their forms are band-shaped lines of natural winding with different thicknesses,which are approximate to the classical connective lines between the classical channels and collaterals and acupoints (il- lustrated lines),and similar to the lines of needling response propagating along channels and band-shaped lines of isotope tracing along channels.The followings are about studies on structures,channel-qi,the pathway of qi, regulation and essence of channel and collateral courses.
