Types: Yin and Yang meridians (e.g., Lung, Large Intestine, Stomach, Spleen, etc.)
Function: Carry Qi and blood
8 Extra Vessels
Types: Du, Ren, Chong, Dai, etc.
Function: Carry essence (Jing or kidney essence)
Connect to essence to protect it
Layers Above the Main Meridians
12 Divergents
Function: Connect internal and external parts of the body
Extend pathways of the 12 main meridians (e.g., Large Intestine divergent from the shoulder)
15 Collaterals
Function: Reinforce the yin-yang connection of meridians
Some books reference 16 instead of 15
Additional Functions:
Carry Yin Qi (nutritive Qi)
Buffer between external (muscular/dermatome layer) and internal (deeper meridian layers)
Physically expel pathogens from internal to external
Emotionally expel repressed emotions
Usage may trigger emotional release like crying
12 Muscular Regions
Location: Below dermatomes
Function: Correspond to main meridian areas (e.g., Extensors of Large Intestine)
Help diagnose underlying issues
12 Dermatomes
Location: Superficial layers (skin)
Function: Correspond to main meridian areas
Address skin issues (e.g., Psoriasis or eczema on the Large Intestine dermatome)
Provide clues on internal health issues
Summary
Meridians range from deep to superficial, with each layer having its specific function and diagnostic indication.
The balance and connection between internal and external aspects of the body are crucial for health, facilitated by different meridian structures and their functions.