The large intestine
The large intestine connects with the fei-lung. The large intestine absorbs the residue of water and turns the rest of the food into feces. Disturbance of this function results in diarrhea or constipation due to the 'descent of qi'.

The urinary bladder
The urinary bladder connects with the shen-kidney. The bladder stores and then discharges urine from the body.

The sanjiao
In Chinese the sanjiao means the three cavities. The xin-heart and the fei-lung are in the upper jiao (the chest), and they transport qi and blood to all parts of the body in order to nourish the body. The pi-spleen and stomach are in the middle jiao (the epiastrium) and they digest and absorb food. The shen-kidney and bladder are in the lower jiao (the hypogastrium) and they control water metabolism and the storage and excretion of water. The sanjiao is also sometimes called the triple warmer organ. This is because the three body cavities are intended to control the body temperature.

Extra Organs

The brain
The brain is a sea of marrow, i.e. it is an enlarged part of the spinal cord. The shen-kidney produces the marrow that fills the brain. If the essence of shen-kidney is absent then there is inadequate marrow for the brain. In traditional Chinese medicine the function of the mind is included in that of the xin-heart.

The uterus
The function of the uterus is to control the menstrual cycle, develop the embryo and nourish the foetus. The qi and blood of the channels pass into the uterus through the chong and the ren channels, so that the qi of the body is able to influence the flow and regularity of the menstrual cycle.

IV. Qi, Blood And Body Fluid
Qi, blood and body fluid are important substances and structures in the body. They sustain the vital activities and they nourish the body, thereby keeping the functions of the tissues, organs and channels in good order. The production and circulation of qi and blood also depends on the health of the tissues and organs that are nourished by these substances.

Qi
Qi is a complex concept; it relates to both substance and function. Clean qi (oxygen), waste qi (carbon dioxide) and qi (nutrients) are generally known as material qi, and the existence of material qi is shown by the functional activity of various organs. The function of an organ depends on the functional qi of that organ; for instance, qi of xin-heart or qi of pi-spleen is the vital energy and functional activity of the xin-heart or pi-spleen. The function of an organ, or its functional qi, cannot exist without material qi, and vice versa.

Zhong qi
Zhong qi is found mainly in the chest. It nourishes the structures and functions of the xin-heart and fei-lung.

Nourishing qi
Nourishing qi circulates in the channels and collaterals, mainly in the viscera

Defensive qi
Defensive qi is in the muscles and skin. It circulates outside the channels, in the subcutaneous tissues, and it defends the body against invasion by pathogens.

The original qi is nourished and maintained by qi derived after birth. These combine to form genuine qi, i.e. the total sum of qi in the healthy body. This contrasts with pathogenic factors that are known as pathogenic qi.

Blood
The nutrients from food are digested by the pi-spleen and stomach and they are then transported to the xin-heart and fei-lung and turned into red (oxygenated) blood by qi. The essence of shen-kidney produces bone marrow, and bone marrow uses the digested food to produce blood.
Qi of shen-kidney promotes digestion by pi-spleen, which in turn strengthens the xin-heart and fei-lung. This interaction therefore promotes haemopoesis.

There is a close relationship between qi and blood. The formation and circulation of blood depends on qi, whereas the formation and distribution of qi, as well as the health of the various organs of the body, is dependent on adequate nourishment from the blood. If the flow of blood 'stagnates' the circulation of qi is 'retarded' and, conversely, if the circulation of qi is 'retarded' then the blood flow 'stagnates'.

Body Fluid
Body fluid is formed from food and drink. It exists in the blood, the tissues, and all the body openings and cavities.

V. The Pathogenesis of Disease
In traditional Chinese Medicine various elements and other factors cause disease. These are known as pathogenic factors or pathogens. Normally the human body is able to resist pathogens and maintain a healthy balance between the body and the environment. This ability is a function of normal qi, especially the defensive qi.

Disease develops because normal qi is unable to resist the onslaught of the pathogenic qi; if pathogenic qi overwhelms normal qi then a functional disturbance of the body results. The major principle of treating a disease in Chinese medicine is to strengthen and protect normal qi and maintain a healthy body. In ancient China a physician was only paid while his patient was healthy, not while his patient was ill!

Pathogenic Factors
These are divided into three main groups, exogenous pathogens, mental pathogens and various miscellaneous pathogens. 'Phlegm and humour' and 'stagnant blood' are pathological products; once they are formed new pathological changes will ensue so they are considered to be secondary pathogens.

Pathological factors serve as a generalization of clinical symptoms and signs, reflecting the struggle of normal qi and pathogenic qi. By differentiating the clinical symptoms and signs the cause of the disease can be traced, and then treatment can be determined. In order to do this the diseased organs must be defined and the pathogen causing that disease must also be diagnosed. This is called the 'determination of treatment on the basis of the differentiation of a syndrome', and it is the basis of diagnosis and treatment in Chinese medicine.

The Exogenous Pathogens
These refer to six relatively abnormal meteorological conditions; wind, cold, summer heat, damp, dryness and heat (fire, warmth). The diseases caused by these pathogens include most viral, bacterial and protozoal diseases and some 'allergic' conditions such as urticaria.

	cold and damp				normal qi of
	invade pi spleen			pi-spleen is
	impairing its function		        overpowered

	
				
	symptoms of disease—			impairment of the
	anorexia. abdominal distention,		function of pi-spleen
	pain, diarrhoca, cold extremities,
	greasy white tongue, deep thready  pulse

Wind
This pathogen is characterized by movability (of symptoms) and changeability. The clinical manifestations are abnormal limb motion, such as spasm or twitching, and a wandering symptomatic site as in urticaria or arthralgia. The symptoms may vary in intensity and they usually include a dislike of wind, fever, sweating, headache and an itchy throat.

Cold
Invasion of cold will consume the yang causing a contraction of the channels and the blood vessels, and therefore a poor circulation of qi and blood. The symptoms are those of a slight fever, a dislike of cold, hypohydrosis, headache, muscular pain and spasm, and occasionally a dark blue and painful area in the local muscles and skin; a frozen shoulder is a good example of the pathogen cold.

Summer heat
This only occurs in the summer; it damages the yin and may progress to affect the level of consciousness. The symptoms are excessive body heat, profuse sweating, thirst, a dry mouth, dry red skin and, in severe cases, delirium (this is known as heat exhaustion in Chinese medicine). Summer heat may combine with wind and cause convulsions. Summer heat often combines with damp to produce dizziness, nausea, a stuffy sensation in the chest and general malaise.

Damp
Diseases caused by damp are sticky, muddy, greasy and stagnant. Damp causes a generalized heavy feeling associated with distension, dizziness and a heavy head, general malaise and a stuffy sensation in the chest. The patient may also complain of abdominal swelling and an exudative and prolonged skin disease.

Dryness
Dryness consumes yin fluid. There may be a dry sore feeling in the nose, mouth and throat, a coarseness of the skin, or a cough with scanty sputum and possibly haemoptysis. Tuberculosis is an example of the pathogen dryness.

Heat (fire, warmth)
All these represent the same pathogen, but at different intensities. Fire is the most severe and warmth the mildest. As with summer heat the yin may be damaged and this will affect the level of consciousness. The main difference is that summer heat only occurs in the summer and is generally less severe than fire. Diseases that are caused by heat are generally of abrupt onset and rapid change, they are nearly always acute infections. Initially the patient may complain of a high fever, chill, thirst, restlessness, irritability and profuse sweating. In severe cases the patient may be in coma with convulsions.

Mental Pathogens
These are overjoy, anger, anxiety, overthinking, grief, fear and fright.

Excessive fear and fright, or overjoy, injures the xin-heart. This causes palpitations, insomnia, irritability, anxiety and mental abnormality.

Excessive anger causes dysfunction of the gan-liver. This impairs the function of freeing, and causes pain and distention in the costal and hypochondriac region, abnormal menstruation, depression and irritability. If the function of storing blood is disturbed then menorrhagia and hemorrhage can result.

Excessive grief, anxiety and overthinking cause dysfunction of the pi-spleen and stomach. This causes anorexia and a feeling of fullness or distension after meals.

Excessive grief, anxiety and anger cause poor circulation of qi and blood. If there is retardation of qi and stagnation of blood then this can cause a tumor.

Miscellaneous Pathogens
Irregular feeding
Overeating, or eating too much uncooked or cold food, impairs the function of pi-spleen and stomach and causes nausea, vomiting, heartburn, sour regurgitation and diarrhea, for example dyspepsia, gastritis and enteritis.

Over-indulgence in alcohol and an excess of fatty or hot, pungent food produces damp and heat, or phlegm and heat, in the pi-spleen and stomach. Initially dyspepsia results but in more severe cases hypertension, enteritis, gastritis, cirrhosis, cancer or ischaemic heart disease can result. All these are related to nutritional habits.

Too little food intake, or lack of some essential material in food may cause malnutrition. This results in a deficiency of qi and blood which causes emaciation, lassitude, palpitations and sometimes coma.

The intake of contaminated food may impair the function of pi-spleen and stomach, and cause intestinal infections and various parasitic diseases.

Too little or excessive physical labor
Excessive physical labor results in feebleness, emaciation, palpitations and dizziness.

Too little physical exercise causes a poor circulation, limp muscles, soft bones and obesity. This lowers the resistance of the body to disease.

Traumatic injuries
These are the same as in Western medicine.

Appendix
Stagnant blood and phlegm and humour are pathogenic products that may cause further pathological change if they are not eliminated. They have substantive and non-substantive meanings. Substantively they could be described as a blood clot or sputum, the non-substantive meaning is a generalization of a clinical syndrome, for instance, the stertorous breathing that may occur after a severe stroke is described as 'phlegm covering the orifice of the xin-heart'.