Prana means life force, or vital energy flow. This force exists in everything in nature and the universe. There is nothing which has no prana. When prana no longer exists in us, it means we have died.
Since all natural things contain prana, it just means some have a higher or less frequency of prana. Starting from the lowest is the mineral world. The higher level of prana in the mineral world is a diamond, it reflects light, is beautiful, and very strong. Another example are the Himalayas. We are noticing changes in Prana within the Himalayas with the changes in rain, mudslides etc.
The next are plants which grow, but typically at a slow speed. A higher degree of prana would be the venus fly trap which has evolved to catch its prey. Following are animals. Within this group, one can notice a high degree of difference, in size, sensitivity, and consciousness. Last are humans. The degree of freedom is the highest within humans. Size, consciousness, IQ, physiological makeup etc. We are even aware of how to control and expand this Prana in the body through Pranayama practice.
The major receiving ends of prana in the human body are in the upper part of the body. Chest, face, eyes, nostrils, ears. People who have issues with asthma, sinusitis are not receiving plana freely and may be blocked somewhere. We receive prana from our senses; breath, taste, nose, eyes etc. Once prana is received, it must be converted into a useable form. The second state is Samana, the area of digestion. What we take in must be processed and converted. Following is Vyana, which is transportation, taking this energy throughout the body. Apama the 4th state, takes out all that is not needed in the body, or the waste. This is the area below the navel, all must be eliminated which is not used. The last part is Udama, which is what remains, and the finest part which is left over, and all goes to the head.
Most yoga practitioners have issues with Samana or digestion. We take in a lot, but are not able to digest well. Many Pranayam practices help with this, and help to transport this energy through the body. One main object of yoga practice is to work with these functions and optimize.
One final energy to be discussed is Kundalini. This is an energy which is in a dormant state until awoken. There are many misconceptions about Kundalini, but feel it is a psychic concept. When we begin practicing yoga we begin to see changes in our daily lives. If we look back 3, 6, 12 months we see how our perception, our consciousness and awareness has evolved. This is Kundalini. It is a gradual process that changes day by day. By practicing asanas, breathing exercises, and Pranayam, we can increase the level of energy in the body, and begin to expand our awareness, and consciousness.