Our physical body features an anatomy of bones, blood vessels and nerves. Yoga talks of a subtle anatomy of nadis, which we can call the subtle counterparts of our nerves. There are many nadis in our body-brain system, the most important being the sushumna. It is this nadi which is responsible for and controls what we call death.
The sushumna is like a cable with three parts, each within the other. The outer or thinnest layer is known as the vajra nadi. The thick inner cable is called the sushumna and the thin, very fine central and silvery strand is the chitrini nadi. It is the outer core or the vajra nadi that plays a dominant role in our lives and in our death. Both the sushumna and the chitrini are dormant, and can only be activated by the higher practices of yoga.
At the point of death, we will feel a deep pulling within us. This will be the vajra nadi being pulled just like the string of a bow. The arrow on the bow is us - not the physical but our subtle form, made up of our psychic body and the divine fragment in us, which many call the aatma. This arrow is going to be shot into an unknown dimension, though with hard practice and proper guidance this whole process can be mastered and known.
How will we know the final moment has come? Many a time, we see someone we know but try as we would, we just cannot remember their name. Similarly, in this extreme pulling, a moment comes when we cannot remember our own name. This is the moment of the final exit.