TCM- Functions of the Kidney

Kidney

Functions:
Stores Essence and Governs Birth, Growth, Reproduction & Development
Produces Marrow, Fills up the Brain and Controls the Bones
Governs Water
Controls Reception of Qi
Opens into the Ears
Manifests in Hair
Controls Spittle
Controls the 2 Lower Orifices
Houses Will Power
Controls the Gate of Life

Here are some of those functions in a little more detail:

Stores Essence and Governs Birth, Growth, Reproduction and Development:
2 Aspects of Storing Essence function:
1. KDs store the Pre-Heaven Essence
a. The Essence determines our basic constitution, strength and vitality. It is also the basis of secual life, and the material foundation for the manufacture of sperm in men and the ova and menstrual blood in women
b. Menstrual blood is different from other types of Blood in that it derives directly fromthe Kidney-Essence
c. Insufficient essence may be a cause of infertility, impotence, underdevelopment in children (mentally and/or physically, retarded frowth or premature senility.
2. KDs store the Post-Heaven Essence, that is, the refined essence extracted from food through the transforming power of the Internal Organs

Produces Marrow, Fills up the Brain and Controls Bones:
The TCM definition of Marrow is a substance that is the common matrix of bones, bone marrow, brain and spinal cord.

The Marrow is also the basis for the formation of bone marrow, which nourishes the bones.
If KD Essence is strong, the bones will be strong and the teeth will be firm.
If KD Essence is weak, the bones will be brittle and the teeth loose.
Weak KD Essence in children will cause poor bone development, pigeon chest, etc.
The decline of KD Essence occurring with menopause in women means that the Essence does not nourish the Marrow and bones so that they become brittle, leading to osteoporosis.

Governs Water:
-The KDs can be compared to a gate that opens and closes in order to control the flow of Body Fluids in the Lower Burner. Under normal physiological conditions there will be a correct balance between Kidney- Yin and Kidney-Yang resulting in the correct regulation of the opening and closing of the 'gate.' Urination will be normal in quantity and color. In disease, there is an imbalance between Kidney-Yin and Kidney-Yang resulting in a malfunctioning of the 'gate' in opening and clsoing: it will either be too open (deficiency of KD Yang causing profuse and pale urination, or too closed (deficiency of KD Yin) causing scanty and dark urination.
-The KDs receive fluids from the Lungs, some of which are excreted and some of which are vaporized, in which form they return to the Lungs to keep them moist.
- Finally, the SP plays an important role in the transformation and transportation of Body Fluids. KD Yang provides the SP with the heat it needs to carry out its function of transforming and transporting fluids.

Opens to the Ears:
The ears rely on nourishment of the Essence for their proper functioning, and are therefore physiologically related to the KDs. If the KDs are weak, hearing may be impaired and there may be tinnitus.

Functions of the Gate of Life:
1. Is the Root of the Original Qi
a. If the Fire of the Gate of Life is deficient then Original Qi will suffer, and will inevitably lead to a general deficiency of Qi and Blood.
2. Is the Source of (physiological) Fire for all the Internal Organs
a. All the organs rely on the heat provided by the Fire of the Gate of Life to function properly.
- The Spleen needs its heat to tranform and transport food essences
- The Stomach needs it to rot and ripen food
- The Heart needs it to house the mind
- The Lungs needs it to send and diffuse Qi
- The Liver needs it to ensure the free flow of Qi
- The Intestines need it to move fod and stools
- The Gall Bladder needs it to secrete bile
- The Triple Burner needs it to transform and excrete fluids
b. If the Fire of the Gate of Life declines, the functional activity of all organs will be impaired, leading to tiredness, mental depression, lack of vitality, negativity and a promounced feeling of cold
3. Warms the Lower Burner and Bladder
4. Warms the Stomach and Spleen to aid digestion
5. Harmonizes the sexual function and warms the Essence and Uterus
a. The Fire of the Gate of Life is essential for a healthy sexual function and to warm the Essence and the Uterus. The Fire of the Gate of Life (Minister Fire) could be seen as the Yang aspect of the Essence. Sexual performance, fertility, puberty and menstruation all depend of the Fire of the Gate of Life.
6. Assists the KDs function of reception of Qi
7. Assists the Heart's function of housing the Mind