That is Ishvara’s mysterious MAyA shakti! All this because, the heart is the locale for the ego.
The nADis that control and monitor the jIva’s personal matters of life start from there and proceed to the other organs giving them the life-force, as we have seen earlier.
Several semi-flesh nAdis go forth from this heart in all directions. Among them are those which end in one of the nine Gates. (*nava-dvAra*).
For all those who have to take another birth – in other words, for ninety-five percent. of all the people, life leaves through one of these gates.
Besides these nine there is a gate of the size of an atom at the top of the head. For all people life enters into the foetus through that gate.
But at the time of death of all those who have to have another birth, life leaves not by that gate but by one of the other nine gates.
For those who do not have to be born again, other than the JnAni, life leaves only by the gate at the head.
That is what is called “kapAla-mokShaM”.