The San Jiao is the division of the upper, middle and lower parts of the body into the upper, middle and lower jiao. The San Jiao is the pathway for the elevation of qi in and out of the body, as well as the channel for the operation of vital energy and fluid.
1. Upper Jiao: generally refers to the chest above the diaphragm, including the heart, lungs, organs and the head and face, which are collectively known as the upper jiao. The upper jiao is like a fog, which promotes Wei qi, transmits and distributes the essence of grains, blood and fluids to nourish and moisturize the whole body.
2. Middle Jiao: refers to the upper abdomen below the diaphragm to the umbilicus, including the spleen and stomach, liver and gallbladder. The middle jiao is like a compost, secrete the dross, steam the fluid, transform its essence, inject it into the heart and lungs, transform it into blood, nourish and moisturize the whole body.
3. Lower Jiao: The area below the umbilicus is called the Lower Jiao, including the small intestine, large intestine, kidney, bladder, woman’s uterus (generally referred to as the uterus), the seminal chamber and the two lower limbs. The Lower Jiao is like a blasphemy, with the function of excreting dross and generating and excreting stools.