Chakras are the nerve centres in our body. There are 1,72,000 nadis (channels of metaphysical energy or life-force) in our body, and there are various nerve centres for these 1,72,000 Nadis. It is one energy that manifests itself in different ways in the different regions of the body.
Muladhara Chakra is at the root of the body which flows through the spine and the topmost chakra is called as Sahasrara Chakra.
This upward or downward flow of energy keeps on happening very naturally and spontaneously in life all the time.