- (1) Shen stores vital Essence and governs birth, growth, reproduction, and development
- (2) Shen governs water metabolism
- (3) Shen controls the reception of Qi
- (4) Shen produces marrow, enriches the brain, and transforms Blood
- (5) Shen controls the bones
- (6) Shen opens into the ears, the external genitals, and the anus
Shen is partly composed of the two Kidneys located at the back of the waist, one on either side of the spine; it has a bright black aura light. The Basic Questions says, “The waist is the residence of the Shen” .
Shen with many intangible functions, is quite different from the CWM meaning of “kidney”, It stores “innate Essence,” the origin of life, and is the basis of Yin–Yang, “the origin of the innate constitution.” Shen correlates with Water in the Five Elements Theory, but paradoxically it is also the source of Fire in the body. This Fire, “Fire of the Vital Gate” (Ming Men Huo, ), can be conceptualized as residing deep under water or as a dragon lying in the water.13 Shen belongs to Yin within Yin, which is the foundation of both Yin and Yang for all other organs. It transforms Qi and produces Blood. The Shen Meridian rises from the soles, ascends along the back of the legs, goes through the Kidney viscera, then in front of the Liver and Lung, and ends on both sides of the tongue root. The Shen Meridian is internally–externally related to the Bladder Meridian. The Shen system is composed of the Kidneys, Marrow, Brain, hair, Bone, ears, external genital organs, and anus. Shen is viewed as the congenital base of life.
The physiological and mental functions of Shen (, Kidney, with its aura and meridian as one union)
(1) Shen stores vital Essence and governs birth, growth, reproduction, and development
Shen’s vital Essence or congenital Essence, the root of life origin in the embryo, is a precious substance inherited from one’s parents and replenished by extracted food Qi. It is vital to the body’s formation and supports growth, development, and reproduction. Congenital Essence nourishes the viscera, and transmits the surplus acquired Essence into Shen for future use.
Although congenital and acquired Essence differ in origin, both are stored in Shen, where they combine with, depend on, and supplement each other. The combined Essence forms the Essence Qi of Shen, which influences life and death.
If Shen cannot store Essence-Qi, Shen-Yin and -Yang will be deficient. Deficient Shen-Yang is manifested as listlessness, aversion to cold, cold limbs, soreness and weakness of the waist and legs, dysuria, enuresis with edema, or impotence, premature ejaculation, watery leucorrhea, and sterility.
Shen-Essence determines Shen function. The Basic Questions says, “The Shen is the strong or sexual official from whom initiative is derived” . If Shen-Essence abounds, Shen-Qi, -Yin, and -Yang with flourish and support sexual function, and there will be great vitality with sexual power and fertility. If Shen-Essence is weak, it may lead to poor development of the sex organs and will be unable to optimally support reproduction.
(2) Shen governs water metabolism
Shen belongs to Water in the Five Elements Theory, and transforms, transports, distributes, and metabolizes body fluid; or, Shen opens and closes a gate to control the flow of body fluid. Directed by Shen-Qi, Shen disseminates water to the whole body through the San Jiao waterway. Shen separates the metabolized fluid for reuse, or discharges it as sweat and urine. Shen-Qi supports San Jiao’s absorption in the Small and Large Intestines. The Fei, Pi, and Bladder viscera also participate in water metabolism. When Shen transforms Qi optimally, the purified water will go up through San Jiao to Xin and Fei to be reused. The turbid remainder will become urine, traveling through the Bladder to be discharged, which is controlled by Shen’s action of Qi transformation.
(3) Shen controls the reception of Qi
Fei inhales air and sends fresh Qi (energy) to Shen, i.e. Fei (Metal) produces Shen (Water), as outlined in the Five Elements Theory. So, respiration is controlled by Fei, the fresh Qi inhaled by Fei from the outside world, but is also coordinated by Shen, which retains or receives the Qi. The energy inhaled by Fei must descend deeply into Shen (this is an intangible meaning with energy), which supports deeper respiration to supply oxygen to all parts of the body. When Shen-Qi is weak, and fails to secure the inhaled and descending Qi, breathing will become shallow and will present as hypopnea, prolonged expiration, chest congestion, and asthma.
(4) Shen produces marrow, enriches the brain, and transforms Blood
The Essence stored in Shen produces Marrow, which does not correspond to “bone marrow” only in CWM, but includes cerebral, Spinal cord, and Bone Marrow. The Shen-generated cerebral and spinal cord Marrow nourish and maintain the functions of the Brain. In TCM, the Brain has a physiological connection to Shen, and Shen is the origin of intelligence. Therefore, Shen determines both physical strength and mental intelligence. Sufficient Shen-Qi promotes a well-developed Brain; insufficiency presents as headache, poor memory and concentration, dizziness, amnesia, dull thinking, poor vision, and so on.
Shen-Essence, assisted by Pi and the Stomach, which transform food nutrients, ensures abundant Blood production. Shen-Essence and Blood promote and transform into each other. Therefore, Blood deficiency syndromes due to Shen-Essence deficiency are treated by nourishing Shen-Essence.
(5) Shen controls the bones
Bone development and function depend on Shen-Essence, or “the Shen regulates the bones,” because Shen-Essence transforms into bone Marrow to nourish and form the bone matrix. The Shen-stored Essence promotes skeletal growth and repair. The Basic Questions says, “The Shen controls the bone marrow … if the Shen has Heat, the spine will not be straight, the bones will wither and the marrow will decrease” . Deficient Shen-Essence will present as a weak skeleton, brittle bones, loose teeth, poor development or a “pigeon chest” in infants, and susceptibility to fracture in the elderly.
(6) Shen opens into the ears, the external genitals, and the anus
Shen-Essence produces Marrow and nourishes the ears. When it is insufficient, the cerebral Marrow will be deficient and will present as tinnitus, deafness, dizziness, and slow reaction. Thus, because Shen-Essence declines with age, the elderly commonly suffer hearing deficits.
Urine excretion depends on Shen transporting Qi to the Bladder. The urethra is an orifice of Shen. Shen also controls reproduction, and thus the external genitals are an additional orifice of Shen and sperm is the outer manifestation of Shen. Deficiency of Shen-Essence presents as frequent urination, enuresis, leucorrhea, or spermatorrhea.
Shen influences the Large Intestine and the anus to control defecation. Insufficient Shen- Yin and Shen-Yang leads to constipation; deficient Shen-Yang leads to diarrhea or anal prolapse.