Our pranic (or energy) body is fuelled by the chakras, or psychic centers, which are subtle, high-powered vortices of energy in the body. They receive and store the Cosmic prana, and act as transformers to step down the level of energy, so that it can be used by different organs and parts of the body.
The 6 main chakras located along the spinal column are: Mooladhara (Root Chakra), Swadhisthana (Sacral Chakra), Manipura (Solar Plexus Chakra), Anahata (Heart Chakra), Vishuddhi (Throat Chakra) and Ajna (The Third Eye). Although these centers are situated in the subtle body, they correspond to the nerve plexuses in the gross body. Beyond this six are 2 other centers of awakening: Bindu and Sahasrara (The Crown Chakra), whose perception is acquired only at significantly evolved stated of consciousness.
Each chakra vibrates at a particular rate and velocity. The lower chakras operate at lower frequency, are grosser and create grosser state of awareness. Chakras at the top of the circuit operate at a higher frequency and are responsible for higher intelligence.
When chakras are purified, rebalanced and awaken, the pranic level is higher and more stable, and there is little difficulty in awakening and experiencing the transmission of prana.