By itself the Prana or vital force principle is one only but in a creature’s body based on its function it is divided into many classes. The chief organs of the body are made up of flesh, muscles etc but due to differences in the union their shape etc are different. On this very basis its naming and description are varied. In the human body the vital force too has to shoulder different responsibilities. On their basis their naming is varied and designing/qualities too are different. But at the root of these variations there exists unity. Vital force is one and not many. Electricity is one but based on various technology and apparatus it is used variedly. While using heaters, coolers, fans, tube lights etc its energy and nature appears different. Keeping in mind utility and aim differences maybe perceived yet we know that it is but the multifaceted functioning of single electricity. With reference to vital force this too is the case. Scriptural scholars have classified them in many parts, many names have been assigned and many modes of description have been given. Despite it being appropriate we must not fall under the illusion that vital force is of many types and that they are different and separate. The classification of vital force can be said to be a manifestation of ‘Ekoham bahusyama…’ i.e. ‘I was one and desired to become many.
In the human body the vital force has been demarcated in 10 ways. In that 5 are vital force and the remaining five are sub vital forces. The Vital Force Sheath comprises of these 10 put together. There are 5 chief vital forces 1) Apan 2) Saman 3) Prana 4) Udan 5) Vyan. The sub vital forces are 1) Devadatta 2) Krukul 3) Kurma 4) Naag 5) Dhananjaya.
In the bodily arena what are the functions of these vital forces? This has been elucidated in the Ayurved scriptures as follows:
1) APAN: Apan is that vital force which has the capacity to throw out dirt from the body. For example it throws out feces, urine, sweat, phlegm, sperm, helps in fertilization of ovum, sperm etc.
2) SAMAN: It carries bodily juices in an apt manner to appropriate places and distributes them. It produces digestive juices and maintains its wholesome quality. In the Patanjali Yoga Sutra (3rd leg, aphorism 40) it is said that via Saman the energy and functioning of the body is kept active.
3) PRANA: It circulates inhalation/exhalation and food and also energy in the body. While talking about vital force Prana word is used predominantly.
4) UDAN: It keeps the body on its toes, keeps it hard and does not allow it to fall down. Many visible and subtle upward movements in the body take place because of it.
5) VYAN: It is spread out in the entire body. It controls the body via blood circulation, breathing process, nerves etc. It aids the voluntary bodily movements of the subtle mind. Star Plus Energy