According to Theosophy and Alice Bailey, the Physical Body is thus composed:
Dense part
Composed by matter from the three lower sub-planes of Physical Plane: Solid, Liquid, Gaseous.
This is the part we see, and can be studied in Anatomy and Physiology books.
Etheric part
Composed by matter from the four higher sub-planes of Physical Plane: Etheric, Super-Etheric, Sub-Atomic, Atomic.
The Permanent Physical Atom is located in the Atomic sub-plane, and it is the Atom which forms the next body in the next incarnation, according to its evolution and the individual Karma.
Every evolutive effort related to the Physical Body is engraved in this Atom, and forms the basis of the new physical body in the next incarnation.
This part Etheric of the Physical Body is not visible, except if one have Physical Clairvoyance developed, an Yoga Siddhi.
In this Etheric part is located the Chacras and the Acupuncture Meridians.
When the death of the Physical Body occurs, this Etheric part is dissolved as well, and only the Physical Body Permanent Atom goes to the Causal Body, also called Higher Mental Body.