I present this list only as an example, because the literature on the segments is extremely varied. Iyengar wonders whether these zones might correspond to the endocrine glandular system that regulates the major movements of the organism
To awaken a chakra, the devotee must be able to move the designated area of the body in coordination with the respiration, associated affective mechanisms and mental representations. When all of these can be vividly integrated, the disciple moves on the next door. Once two doorways have been opened, the metaphor of the snake is there to remind us that each door refers to a psychoorganic whole, and that the coordination of the segments must acquire the same continuous grace as that of a cobra that dances vertically to the sound of a flute.
You may try and see how difficult it is to get the spinal column to move like a serpent while you breathe comfortably for ten minutes. We often find this type of movement in dances from around the world.