Section 2 Blood
I. Concept of Blood
Blood means the blood fluid. It is a red fluid with rich nutrients flows in the vessels. It is a basic material of body composition and for the life activities. In order to have normal physiological function it has to flow within the vessels. The vessel has the function to prevent escaping of blood so that it is called"blood house". As soon as the blood leaks from the vessels, it losses its nourishing function which is called bleeding or "the blood which left from vessels".
II. Formation of Blood
Blood consists of the nutritive qi and body fluid. There are two sources of blood formation. The spleen and stomach are the source for the formation of qi and blood. Blood is generated from the essential substance of drink and food, which is transformed via the function of the spleen and stomach in middle-jiao. So blood is formed by the process of essential substance of drink and food transformed into the nutritive qi and body fluid,and then into blood via the spleen and stomach functions. As for the regeneration and formation process of blood,TCM stress that it should be via the function of nutritive qi and the Lung Meridian. On the other hand ,the essence and blood can be transformed into each other.
There is the relation of mutually transforming and changing between the essence
and blood. Blood produces the essence while the kidney-essence is the important sub
stance in transforming blood. Modern medicine believes that the bones and marrow art the important organs to produce blood,which is the same as TCM theory in which the essence and blood can transform each other. Generally speaking,the abundance of the essence-qi in the kidney may lead to the normal nourishment of the liver and normal replenishment of blood; and the abundance of liver blood may lead to normal storage of the kidney and normal transformation of the essence. So it is said ~ "Eessence and blood have a common source".
III. Physioiogical Functions
1. Nourishing and Moistening Function
Blood flows constantly in the blood vessels. It reaches to the viscera internally and to the skin,muscle ,tendons and bones externally. It nourishes and moistens the viscera,tissues and organs in the body incessantly as to maintain their normal physiological activities. In Classic on Medical Problem,Problem 22 says: "Blood dominates the nourishing and moistening", which is briefly summarization of the function of blood. This function is manifested by rosy with luster complexion, plump and strong muscle sleek of hair and keen perception and quick in movement. If blood is insufficient or endured exhausted by protracted illness, or weaken the function of nourishing and moistening, it may result in the clinical manifestation of dizziness, pullid complexion, dry hair and skin,and numbness of the limbs.
2. Blood Nourishing the Vitality
Blood is the substantial basis for the mental activities. It depends on the abundance of qi and blood, flow freely of blood that to be full of vigor and to have perfect consciousness, keen perception and free movement of human beings. Blood deficiency or abnormal circulation caused by any reason will result in mental disorders in various levels.For example, the deficiency of the heart-blood or liver-blood will appear the symptoms of mental restless, such as palpitation with fright, insomnia and dreamful, in severe cases of haemorrhage, it may occur mental disorders, auch as dysphoria, trance and coma. Therefore, blood is closely related to the mental activities. Only when blood is abundant can the mental activities be remained normal.
IV. Blood Circulation
Blood circulates constantly throughout the body along the vessels ,to provide rich nutrition for the viscera,tissues and organs.
Blood pertains to yin and dominates the stillness. Its circulation mainly depends on the promotion function of qi,It is because of the consolidating function of qi that blood circulates within the vessels.
The normal circulation of blood results from the joint functions of the viscera,meridians and collaterals and vessels ,tissues and organs.
Blood vessels is a relative sealed passage system, in which pectoral qi and blood
flow. So the integrited and free of the vessel is a necessary condition to maintain normal circulation of blood.
Normal circulation of blood also depends on the coordination and balance between
the promotion and consolidation function of qi. The heart controls the circulation of blood. It promotes the flow of blood and services as the motive power of blood circulating. The lung dominates qi and converges the vessels. It helps the heart to promote the blood circulating. The spleen controls the blood. It controls blood circulates within the vessels. The liver stores blood and regulates the blood volume. It governs conducting and dispersing of qi. Qi in motion follows blood flow normally. So the circulation of blood is jointly accomplished by the coordination of the physiological functions of the heart, lung, spleen and liver. The dysfunction of the certain organs will cause the abnormal circulating of blood, and leading to haemorrhage, slow flow of blood, or obstruction of flow, marked by the stagnation of blood.
In addition, the temperature of blood directly influence the speed of blood circulating.
