Application of the Channel – Collateral Theory
As an important constituent part of TCM basic theories, channel-collateral theory can not only be used to explain physiological functions, but also to expound pathological changes, and guide the diagnosis and treatment of diseases.
1. Expounding Pathological Changes
Because channels and collaterals have functions of communicating the exterior and interior, connecting viscera, conveying qi and blood, and reacting and conducting, so in pathological conditions, channels and collaterals may become the pathways of transmitting evils and reflecting pathological changes, therefore, the theory of channels and collaterals can be used to explain the pathological changes in the human body. It is stated in the chapter of Discussion on Skin Divisions in Plain Ouestions, “ Retention of evil in the skin makes the couli ( muscular interstice ) open, giving rise to the invasion of evil into collaterals. When the collaterals are full, it will flow into the channels. When the channels are full, it will get into the zang – fu viscera.” It explains that channels and collaterals are the pathways that exogenous evil is transmitted into zang – fu viscera via the skin and couli ( muscular interstice ). Meanwhile, the channels and collaterals can be pathways that pathological changes among viscera influce each other. For example, Foot Jueyin Liver Channel runs stomach, and connects with the Lung Channel. Therefore, the stagnation of liver – qi can offend stomach, and excessive anger can offend lung and so on. Channels and collaterals can also reflect visceral visceral pathological changes on certain parts of the body surface or its corresponding orifices. For example, liver qi stagnation is always manifested as the pain in hypochondrium or lower abdomen; excess of stomach fire is always manifested as swollen gums; and inflammation of liver fire is always manifested as red eyes and so on.
2. Guiding the Diagnosis of Diseases
Because the channels and collaterals have fixed courses of extension in the body and a fixed connection with the viscera, the symptoms and signs of visceral disease are easily manifested. In clinical practice, the channel – collateral system can be the foundation of diagnosis. For example, pain in both hypochondriac regions is mainly due to liver and gallbladder disease; while pain in the forehead is related to the Yangming Channel. Pain on both lateral sides is associated with the Shaoyang Channel, and pain in the occipital region and nape relates with the Taiyang Channel. Pain in the vertex relates with the Jueyin Channel. The chapter of Qualifications of Acupuncturists in Spiritual Pivot points out, “ When diagnosing a disease, the doctor should find out where the disease locates, distinguish cold syndromes from cold ones and make sure which channel(s) is/are affiliated. “which points out the significance of the channels and collaterals in clinical treatment.
3. Guiding Clinical Treatment
The channel – collateral theory is widely used to guide the clinical treatment of disease in various departments, especially being the theoretical basis for acupuncture, moxibustion, Tuina and pharmacotherapy.
The treatment of disease with acupuncture and moxibustion is attained through puncturing the acupoint or burning moxa over the acupoint to smooth channel qi. These modalities restore the channel’s function of regulating viscera qi and blood of the body in order to achieve the purpose of curing disease. Pharmacotherapy also utilizes the channels. A medicine utilizes the conduction and transportation of the channel – collateral system to target a diseased area, enact a therapeutic effect, and sure disease.
Through long and repeated practice, medical scholars found that Chinese medicinals have selective therapeutic effect on the illness related to a certain channel – collateral and its affiliated viscus. Based on this, they founded the theory of “ channel tropism of medicinal ”, and “ guiding action.” For example, in a formula for treatment of headache, modification may be made according to the channel distribution regions. Qianghuo ( Rhizoma Notopteryii ) is used for headache in the Taiyang channel region; Baizhi ( Radix Angelicae ) for headache in the Ynagming channel region ; Chaihu ( Radix Bupleuri ) for headache in the Shaoyang channel region. These three herbs not only pertain to the Taiyang, Yangming, and Shaoyang channels of the hand and foot, but also guide other herbs through the above channels in order to achieve a stronger therapeutic effect.