Chakras are residents of the astral body. The physical body has several systems like the skeletol, muscular, respiratory, nervous etc., The astral body has the nadis and chakras in which the Panchapranas manifest.
Though there are several big and small chakras, generally we set special interest on the 7 basic ones.
They are as below:
Muladhara - controls the ahankara and basic instincts like fight/flight/fear and is located near the coccyx.
Swadhistana - controls sexuality and creativity and other such and is located near the genitals.
Manipura - controls personality and self esteem and other such and is located in the stomach region.
Anahata - controls love and higher ideals and is located in the thoracic region.
Visuddha - controls communication and self esteem and other such and is located in the throat region.
Ajna - controls intellect, awareness and other such and is located between the eye-brows.
Sahasrahara - leads a living human to enlightenment and is located at the crown.
You can relate the chakras to Maslow's hierarchy which consists of needs centered around physiogical, safety, love and belonging, esteem and self-actualization. It helps if you map the muladhara chakra to the base layer in Maslow's hierarchy which is on the needs surrounding physiological aspects.
Like how, knowledge and practice is propelling a human to self-actualization (in Maslow's hierarchy), transcendental/chakra meditation leads a person to enlightenment and also helps that person acquire higher ideals. It is generally said that life energy is lying in a coiled manner in the muladhara chakra and by transcendental meditation a person is lead to enlightenment by moving this life energy to the crown chakra. This life energy is called - Kundalini.
Knowledge and practice gained by humans aid in this journey to self-actualization and higher ideals. Similarly focusing on astral body by practising transcendental mediation arises the kundalini and gives not only great clarity and heightened sensitivity (of all senses) but helps a person become more humane and loving as the kundalini force crosses the heart/anahata chakra on its way to the crown.
Please read the book - Kundalini - The Evolutionary Energy in Man by Shambhala publications and written by Gopi Krishna.
I believe that, these chakras are probably the centres in which the gross or sthula body, the astral or ghost body and the soul (is believed to be in the center of anahata chakra for an average good person) are pinned. The process of death, hence can be analysed from this understanding and surely is a topic for another time.
But briefly, if you can consider the process of death with the above understanding - the following can be reasonably expected to happen. I have not separated the actions of time and karmic forces in my earlier blogs. But here I do differentiate based on my new understanding.
Time induces aging in the sthula body. As long as karma is waiting to be expended the body lives and thus the sthula body ages as time progresses.
Astral body leaves the Sthula body. (sometimes it is immediately attrited)
Time induces attrition in the astral body. As long as the karma is waiting to be expended (say for instance the unspent karma of a unfortunate soul that committed suicide or a soul that had encountered premature death through some events) , the astral body is attrited by the time.
Pranas are sucked in by MAHAT
1-4 activities can happen all at once or with some delta time difference.
The soul needs to be sucked in too and may need a new stage. If the soul was sucked in via the mooladhara chakra, then it may be placed in the lower realms of the universe where basal life quality is expected to exist. If the soul is sucked via the crown, MAHAT places them in the higher realms of the universe where higher ideal beings are expected to be existing.
Finally the Karmic forces again move the soul to the new womb to begin a new life.
It is interesting to note that the chakras are well defined in humans only and not in animals or plants.
The below is my thought on the MAHAT and Karmic forces.
MAHAT is the dark energy/matter responsible for providing energy/mass for the construction of the universe with its dimensions and for sustaining the various physical laws/processes in different dimensions.
Karmic force is different because it has to intelligently decide a course of action based on the goodness (good karma)/ badness (bad karma) attributable in an entity like human or an entity like an animal in this universe.
Withdrawing a soul and placing them in a stage is a basic action compared to the action of placing the soul in a certain womb (as an example - plant seed or human womb).
Hence I tend to think that the withdrawing and propelling the soul of a human is done by MAHAT but placing it in the right womb is done by the Karmic forces.