Concept of Prana Vayu & Shat Chakras in Marma Chikitsa (मर्म चिकित्सा ).

The Chakra are the regions where in higher concentration of the pranic energy are present.

The chakra is basically defined as "चन्क्रमति   इति  चक्र ". The structure that which continuously moves in circular direction is chakra. Literally speaking the word chakra refer to a wheel. The concomitant current produced due to continuous movement of chakra moves from the region of higher concentration (सहस्रार   चक्र) to the region of lower concentration (मूलाधार  चक्र) in maintaining the flow of energy equivocally in the body and thereby maintaining the health of the individual. 

Shat Chakras

Prana is a central concept in Ayurveda and Yoga where it is believed to flow through a network of fine subtle channels called nADi . Its most subtle material form is the breath,The Pranamaya-kosha is one of the five koShAs  or "sheaths" of the Atma

The Prana circulates inside the body through the chakras.

Paramhansa Swami Maheshvarananda describes a chakra as , "A powerhouse in the way it generates and stores energy, with the energy from cosmos pulled in more strongly at these points. The main nadis, iDA , Pingala and SusymnA run along the spinal column in a curved path and cross one another several times. At the points of intersection they form strong energy centers known as chakras. In the human body there are three types of energy centers. The lower or animal chakras are located in the region between the toes and the pelvic region indicating our evolutionary origins in the animal kingdom. The human chakras lie along the spinal column. Finally, the higher or divine Chakras are found between the top of the spine and the crown of the head.

Anodea Judith  provides a modern interpretation of the chakras: 

"A chakra  is believed to be a center of activity that receives, assimilates, and expresses life force energy. The word chakra   literally translates as wheel or disk and refers to a spinning sphere of bioenergetic activity emanating from the major nerve ganglia branching forward from the Spinal column.  Generally, six of these wheels are described, stacked in a column of energy that spans from the base of the spine to the middle of the forehead, the seventh lying beyond the physical world. It is the six major chakras that correlate with basic states of consciousness.."

 

Chakras & Spinal  Column

Each Chakra  in our spinal column is believed to influence or even govern bodily functions near its region of the spine.Chakras, as described above, are energy centers along the spine located at major branchings of the human nervous system, beginning at the base of the spinal column and moving upward to the top of the skull.

Chakras are described as emanations of consciousness from Brahman, an energy emanating from the spiritual which gradually turns concrete, creating these distinct levels of chakras, and which eventually finds its rest in the Muladhar chakra .The energy that was unleashed in creation, called the Kundalini  lies coiled and sleeping at the base of the spine. It is the purpose of the tAntrik  or Kundalini forms of yoga  to arouse this energy, and cause it to rise back up through the increasingly subtle chakras, until union with God is achieved in the SahsrAra chakra at the crown of the head.

In terms of Kundalini , a meditation process which helps in realising one's self, the energy from the lower level chara (muladhara)  is slowly elevated to reach the higher level of chakra (sahasrara).

The Shat Chakras :-

1.  Muladhara - Base or Root Chakra (ovaries/prostate)
2. Svadishtana - Sacral Chakra (last bone in spinal cord *coccyx*)
3. Manipura - Solar Plexus Chakra (navel area)
4. Anahata - Heart Chakra (heart area)
5.  Vishuddha - Throat Chakra (throat and neck area) 
6. Ajna - Brow or Third Eye chakra (Pineal gland or 3rd eye)

The sahasrara  is a thousand petalled chakra, which is not counted amongst the shat chakras

  some are of the opinion that it is the Crown Chakra (Top of the head; 'Soft spot' of a newborn)

सहस्रार