Channels, also called Meridians, are an important part of Traditional Chinese Medicinal Practice. Meridians play an important part in understanding how acupuncture works and the way acupuncturists understand the human body. Each channel is a part of a system that is involved with the connection and flow of Qi.
The major channels are the liver, spleen, kidney, heart, lungs, pericardium, small intestine, large intestine, urinary tract, stomach, and gallbladder. The main channels are grouped together and relate to important organs in the body. When one meridian is in trouble through being blocked up or unbalanced, it can impact your over-all health and bring on sickness. If the Qi of your lung channels are unbalanced, you likely suffer from lung issues like asthma or an illness of the lungs. An acupuncturist will look for a way to rebalance the Qi of that system.
Each meridian has its own special time period. This is when the specific body organ (meridian) is optimal.
Large Intestine: 5:00a.m. to 7:00a.m. Waking up in the morning
Stomach: 7:00a.m. to 9:00a.m. Breakfast time
Spleen: 9:00a.m. to 11:00a.m. Be active
Heart: 11:00a.m. to 1:00p.m. Lunch and chat with friends
Small Intestine: 1:00p.m. to 3:00p.m. Get optimized, and organized
Bladder: 3:00p.m. to 5:00p.m. Study time, stay hydrated
Kidneys: 5:00p.m. to 7:00p.m. Dinner, second wind time
Pericardium: 7:00p.m. to 9:00p.m. Stimulate your body and brain
Triple Warmer: 9:00p.m. to 11:00p.m. Settling down for the night
Gallbladder: 11:00p.m. to 1:00a.m. Sleep
Liver: 1:00a.m. to 3:00a.m. Dream time
Lungs 3:00a.m. to 5:00a.m. Deep sleep
When the body is healthy, the qi flows through all of the points and channels in ample supply.
Feeling great, and without any chronic illness. The meridians are like lights all strung together. Bulbs that don't light or that dimly lit up correspond to the points that need therapeutic action. Symptoms of disease occur when the qi in some of the meridians becomes weak or blocked.
The following definition is taken directly from shen nong .com
Meridians are a collection of acupuncture points
By connecting and uniting different parts of our body, meridians provide the transport service for the fundamental substances of qi, blood, and body fluids. The flow of qi in the Meridian System concentrates or "injects" in certain areas of the skin's surface. These areas are very small points, otherwise known as "acupuncture points". Although acupuncture points are located externally and superficially, they can affect the internal functions of our body. There are 365 acupuncture points, and each point belongs to a particular meridian channel that connects to specific organs. (1)