Traditional Chinese medicine theory suggests that the human body are functionally connected by a network of channels composed of meridians and internal systems which determines physiological functions in a holistic manner. With this concept in mind, meridian entry (or meridian tropism) refers to a selective biological action produced by a Chinese herb on one or more target TCM systems. This concept is similar to “bioavailability” in modern medicine. Bioavailability refers to the extent a substance or drug becomes completely available to its intended biological destination(s). But unlike the pharmaceutical medication, which can be administered directly to the blood stream or by other means, TCM herbs and foods mostly are taken orally, with a small amount used topically or by inhalation.
Meridian entry refers to which TCM system(s) one herb acts upon. The ancient Chinese learnt about the meridians and the herb's action by long term in vivo experiments, in other words, directly consuming the herbs or giving it to livestocks to observe the effects. Some of the earliest written references to Chinese herbology involve the mythical Emperor Shen Nong, who is considered the father of agriculture and Chinese herbology. Legends say he (or they, a group of people around BC 2700) sampled many many herbs to test their effects as a way of teaching people to be self-sufficient. During this process, Shen Nong was toxicated seventy times in a day. This is clearly an exaggerated form of expression in mythology. This experience and knowledge continue to accumulate and nature over the next thousand years. The Grand Compendium of Materia Medica (Ben Cao Gang Mu) by Li Shizhen (1517-1593) is known as the most comprehensive classic about herbs and food. The author utilized smell, taste, and the growing season to judge the meridian entry of herbs. Throughout thousands of years work, Chinese herbology has a lot of human data on herbal effects thus make it so powerful even in the modern time.
According to TCM theory, meridians allow communication between internal organs and external manifestations of the human body. It means that whatever happens inside our body will find a way to show and express to the outside. We can observe these signals and messages by using the four diagnostic methods of “inspection, listening and smelling, inquiry, and pulse taking”.
Meridian entry is a specific characterization in the positioning and orientation of herbs. When the disease occurs, herbs with different meridian entries can be selected for treatment. For example, palpitations and insomnia are conditions related with the heart meridian and therefore, polygala root (Polygala tenuifolia Willd.), which has the heart meridian entry, is frequently used.
There are 12 main meridians in the human body, each has its own characteristics and functions. Different diseases may be caused by pathogens or lesions at different sites. For example, TCM uses cooling herbs to treat heat diseases. However, the heat source could be liver ministerial fire, heart sovereign fire, stomach fire or large intestine damp-heat, and the herbs clearing liver fire herb do not always clear heart fire, herbs that cool fire do not necessarily dry the dampness. When used inappropriately, the herbs could harm the system that requires no cooling/ cleansing/ tonify, etc. Therefore, different herbs are used to treat diseases due to their imbalance in a specific location hence the importance of the meridian entry of each herb or food. [Read more: Foundation of TCM dietary and herbology (1/4)- Four natures]
Here is a brief introduction of each meridians and example herbs:
For educational reference only, PLEASE DO NO CONSUME ANY MENTIONED HERBS OR FOOD for theraputic purpose. We are not responsible for any adverse effects or damage due to unsuperivosed used of medicinal herbs or regulatory diet.
Heart Herbs entering the heart meridian could treat diseases related with heart’s functional disorders (in modern medicine, often cardiovasicula or psychological symptoms), such as angina, palpitation, irritability, insomnia, or restlessness. Herbs or food: Longan, Jujube date, Salvia miltiorrhiza (Red sage/danshen)
Liver Liver connects the eyes, maintains a smooth flow of Qi and calms the emotions, governs tendons & sinews, and stores blood. Herbs entering the Liver channels could smooth the liver Qi thus regulates the excessive emotions, or tonify the liver Yin or clear the liver fire, and treat eye diseases. Herbs or food: The whole Goji plant, green leafy vegetables [Read more: Yin Yang philosophy and mental health]
Spleen Spleen has a primal function to transport & transmit the water and transform the material into power, muscle and intellectual concentration. The herb entering the spleen channel usually could tonify & strengthen the spleen to treat diarrhea, poor appetite, or fatigue. Herbs or food: Sweet fruits, potato, yam
Lung Lung governs the skin and defends the body from being attacked by external pathogenic factors. Herbs expelling the exterior wind‐cold or wind-heat all enter the lung channel. Herbs or food: Fresh mint, apricot seeds, lily bulb, chinese pear [Read more: Strengthen your Wei Qi for better immunity]
Kidney Kidneys store Essence, “The Root of Life” in TCM, which is our power source and genetic inheritance. Herbs entering the kidney channel could tonify the kidney, clear the heat due to deficiency of water essence, manage fertility, and treat water metabolism disorders. Herbs or food: Walnut, black sesame, Chinese garlic chives, oyster [Read more: Understanding Water energy with TCM]
Pericardium Pericardium is the first line of defence against the heart. Herbs treating the disorders, such as insomnia, irritability, may also enter the pericardium channel. Herbs or food: Bupleurum, Tree Peony Root
Gall bladder The Gallbladder stores and excretes bile, governs decision making and planning, controls the sinews and effects dreams. Some herbs enter the gall bladder channel to help treat the jaundice, clear the damp‐heat in the channel. Herbs or food: Bitter melon, radish, cucumber
Stomach Stomach is in charge of accepting and breaking down the food. It is the key to survival. Without the normal function of stomach, all other systems will collapse. Stomach tends to get hot and dry. By nourishing the stomach and clear out the stomach heat, it relieve stomach acid reflux, improve general energy therefore help with fatigue. Herbs or food: Basically all the food and drinks, Chinese goldthread, rice, ginseng [Read more: Cook your food - digestive system explained in Traditional Chinese medicine]
Large intestine The main function of the large intestine is to receive the waste material sent down from the stomach (both are Yang Ming meridians), absorb its fluid content, and form the remainder into faeces to be excreted. Constipation, damp‐heat diarrhea, or water channel blockage could be related to Large intestine channels. Herbs treating these diseases usually enter the large intestine channel. Herbs or food: Plant-based oil, fiber, rhubarb
Small intestine In TCM, the Small Intestine is the partner organ of the Heart where it plays both a physical and a mental role. The Small Intestine is responsible for receiving and making things thrive. Small intestine separates the clear from the turbid. The disorders of the small intestine may cause abdominal pain, diarrhea, and scanty urine. Thus, some herbs enter the small intestines to treat those diseases. Herbs or food: Carrot, Chinese water chestnut, watermelon peel [Read more: The gut-brain connection and its importance]
Urinary bladder The urinary bladder removes waste water from the body in the form of urine. As simple as it sounds, it is indeed the longest meridian in the body, also the one that most circulate on the surface of our body. It is also the meridian that connects all other meridians. In order to achieve its function and activity, the system must be rich in Qi energy with a smooth flow of water. Herbs entering the urinary bladder not only treat urinary disorder diseases, edema, or to drain the dampness, it also plays an important supportive role in our immunity and overall wellness. Herbs or food: Boiled water, seaweed, black fungus, cogon grass [Read more: Treating a Urinary Tract Infection with Chinese Medicine] [Read more: Acupuncture and Chinese herbs for incontinence]
San Jiao San Jiao, also known as a triple burner, is a special functional organ and could only be found in TCM. It is in charge of the cellular communication of the whole body. It is mainly divided into 3 parts, upper, middle and lower. Each part has it corresponding organ system and therefore the related herbs or food. Herbs or food: Upper burner (Heart and Lung food), Middle burner (Stomach and Spleen food), Lower burner (Liver, Kidney, Large intestine, Urinary Bladder food)