According to Mipham Rinpoche's "Gateway of Knowledge"
12 links of interdependent origination,
The five psycho-physical aggregates, the eighteen constituents and the twelve ayatanas with their subdivisions are the factors which in dependence of each other come together in the process of dependant occurrence. By "name and form" (Nr.4) the five skandhas come together in the way that the four non-substantial skandhas (name) get a base through a physical body (form) which is the embryo.
Depending on "name and form" the inner ayatanas (Nr.5) occur: the ayatana of the eye, the ayatana of the ear, ..of the nose, ... of the tongue, ... of the ... of the body and the ayatana of a mind.
Based on the ayatanas contact (Nr.6) occurs. The capacity of the mind to connect with an object through the sense-faculties: the eye-consciousness is able to perceive form through the eye-sense-faculty, the ear-consciousness is able to perceive sound through the ear-sense-faculty and so on.
Due to the contact sensation (Nr.7) occurs. The embryo in the womb experiences gross sensations. It can be a pleasant sensation, pain ore neutral (indifferent) sensation.
Based on sensation craving or wanting (Nr.8) will occur. When there is a pleasant sensation, the desire to keep that pleasant sensation arises. The desire not to be without this pleasant sensation. When there is an unpleasant sensation, than one has the strong desire to be free from this. This desire can be equally strong, to the desire to have something. Both the desire to want something and the desire to get rid of something belongs to craving - the craving of to have or not to have.
A neutral sensation can also arise. This is, when one either wants to have something pleasant nor he wants to reject something unpleasant.
There are six kinds of craving, related to what sense- objects are involved. There can be craving on form-objects, sound-objects, smell-objects, taste-objects, tangible-objects, or mental objects.
Craving depends further on what realm a being is born in. Depending on ones karma one takes birth in one of the three realms /desire-, form-, formless realm). The craving which arises, is related to the respective realm.
In more details the craving in desire-realm is of 36 possibilities (there are different god-realms, human beings, animals, hungry ghosts, different kinds of hell-realms, altogether it makes up 36 possibilities of craving), within the form realm there are 17 kinds of craving, and in the formless realm there are 4.
Craving makes the "I", the "EGO" manifest. Before craving the potential of the concept or an notation about an "I" is there, is there, but this is the time it manifests.
Due to craving action, the grasping or taking hold of the object (Nr.9) occurs. This is related to the There are 4 kinds of grasping:
1. desirous grasping, 2. grasping for views, grasping for ethics and discipline, , 4. grasping for a self. The notation of an ego, of an I becomes manifest.
Due to "Grasping/taking hold of" existence (Nr.10), occurs in one of the three realms: desire-realm, form-realm, formless realm, according to ones karma).
Due to the existence occurs birth (Nr.11). When there is no obstacle, existence is followed by taking birth into one of the realms depending on ones karma. if there is an obstacle, like the embryo can be intact, but the being does not have the karma, birth does not occur.
Once one is born, as human or animal or in which ever realm, it depends on ones karma, if one fits into that kind of birth one has taken.
Once one is born, the five skandhas which are the basis for suffering are complete and manifested.
INNER DEPENDENT OCCURRENCE
Similarly, the way beings come into existence through the 5 skandhas is a process of dependent occurrence which is demonstrated in the 12 links of dependent occurence.
One system presents the 12 links as the way samsara occurs through a process of dependent occurrence:
1. the cause is ignorance,
2. ignorance lead to actions,
3. actions lead to consciousness,
4. consciousness leads to name and form,
5. name and form lead to the 6 ayatanas,
6 ayatanas lead to contact,
7. contact leads to sensation,
8. sensation leads to craving,
9. craving leads to taking hold of,
10. taking hold of leads to existence,
11. existence leads to birth,
12. birth leads to ageing and death.
Another system presents the 12 links as the way to reverse the process of dependent occurrence and thus get out of samsara:
first ignorance is given up,
when ignorance is given up actions are given up,
when actions are given up consciousness is given up,
when consciousness is given up name and form are given up,
when name and form are given up the 6 ayatanas are given up,
when the 6 ayatanas are given up contact is given up,
when contact is given up sensation is given up,
when sensation is given up craving is given up,
when craving is given up taking hold of is goven up,
when taking hold of is given up existence is given up,
when existence is given up birth is given up,
when birth is given up ageing and death is given up.
1. Ignorance. It means not to see, not to know, not to be aware. What is it that one does not see, know or is not aware of? That is the essence and the nature of everything. Because of this lack of awareness one develops wrong ideas about the skandhas:
In actual fact the skandhas are aggregates which have come together and they are impermanent. Because of ignorance one takes them to be permanent.
In actual fact the skandhas by nature bring about suffering. But when one is ignorant, one does not know that, and one sees them as something pleasant, something positive and the cause of happiness.
In actual fact there is no really existing independent self, but because of ignorance one clings to and identifies with the skandhas as a self.
In actual fact the skandhas is a variety of many different parts which have come together. But because of ignorance one can not see that, and one perceives them as being an entity, one thing.
As long as one has this ignorance of believing in the skandhas as being permanent, as being cause of happiness, as being a self, as being a singular entity, then the obscuring states of mind arise such as the three mind poisons of hate, desire and stupidity. This obscured state of mind causes actions.
2. Actions. The actions one does lead to birth within any of the different kinds of existence within samsara.
Positive actions and merit lead to a birth in the desire realm as a human being.
The result of negative and non-meritorious actions is to be reborn in lower states of existence within the desire realm, like in the hell state or as animals or hungry ghosts.
The result of unmoving actions, which is meditation, is to be born in the upper realms of existence such as form-realm or formless-realm.
As a result of virtuous actions one will experience happiness in the higher states of existence. As a result of unvirtuous actions one will experience suffering in the lower states of existence, and as a result of unmoving actions one will be reborn in the two higher realms of existence.
3. Consciousness It is the consciousness which takes rebirth in any of the existences according to what the actions were. This consciousness has two aspects to it:
a) The projecting consciousness which is going for the next rebirth,wherever it is: whether it is within the desire realm, the form-realm or in the formless-realm. Within the desire realm whether it is as gods, half gods, human beings, animals, hungry ghosts or beings experiencing hell states.
b) The projected consciousness is when the consciousness has come into any of the existences according to its content.It is like the effect, like the fruit.
For the rebirth to happen the causes and conditions have to come together. In this case the cause would be the consciousness seeking rebirth.When all the causes and conditions have come together the consciousness enters the womb and the rebirth has happened. Following the conception come name and form.
4. Name and form Name here refers to the four non-physical or non-substantial aggregates, to sensation, conception, mental events and the consciousness of the new being.
Form refers to the physical body, the embryo which starts to build and form. The first form is a very small and soft whitish substance. As it grows the shape of the body takes form and together with the sense organs the inner ayatanas occur.
Depending on birth ageing (Nr.12) occurs. Because death can happen right after birth, ageing starts in the moment following birth. Time goes, seconds, minutes, hours, days, weeks, months, years. There are some who die after a few seconds, some who die after one week, some after one year, etc. There is no certainty in how old one becomes, if it is only a few days or very old, like 80 years. Following ageing death will come. Death means that the continuity of life ceases. The five skandhas deteriorate again. Also one can say that death as such is happening all the time, each moment ceases, but the continuity is ageing.. But here death relates to the end of ones life-span. The death-experience is very individual. Death is the moment, when the breathing stops. There is the outer breathing and the inner breathing. So there are many variations. It may be that the outer breathing stops and it takes a long time, before the inner breathing stops. Or it can happen simultaneously, or it can happen quite shortly one after another, depending on the karma death itself is experienced very differently. Usually it is a very painful experience, full of suffering , a turmoil. Depending on the individual karma one is saying different things at the time of death. Some are crying for their mother, some start to grieve off sounds of goats or other animals. Others are wailing, or crying, or screaming or whatever. Also one can be very attached and because of that the strongest pain is that one doesn't want to leave. One can be paranoid and full of fear.
Because the kind of karma which one has accumulated, the death-moment will be very individual according to these karma.
Once the inner breathing has stopped, the mind leaves the body and starts wandering. One has left this life, continuity has stopped for this life