The uterus is located in the pelvis, like an upside down pear, posterior to the bladder and anterior to the rectum. The uterus is responsible for menstruation and conceiving fetus. Under physiological conditions, the uterus is to store essence and blood for menstruation or conception of fetus, demonstrating the "storage" function of the zang organs; and discharge menstruation or deliver baby, manifesting the "excretion" function of the fu organs. That is why it is called "extraordinary fu organ" in Neijing or Canon of Medicine. Such physiological functions of the uterus are closely related to meridians, viscera, qi and blood. The uterus is connected with the heart and kidney through meridians.

 The heart governs blood and the kidney stores essence. Only when the heart blood is sufficient and kidney essence is abundant can blood and essence flow into the uterus for the preparation of rnenstruation and pregnancy. Besides, the uterus is also closely related to thoroughfare vessel, conception vessel, governor vessel and belt vessel through meridians. Such an extensive relation with the meridians and vessels enables the uterus to connect with the viscera and well accomplish its function in managing menstruation and pregnancy.