The Concept of Congealing

In the Puranas, the moon (pulmonary vein) is said to be "congealed water" and the sun (lobar bronchus) is referred to as "congealed heat," alluding to its expiratory role. 

 In simple terms, this indicates a movement from the distal ends of the lungs towards its hilum. This "involutionary" or "reverse evolutionary" movement  is termed as "congealing." In respect of the waters (the oxygenated flow), it occurs when the smaller pulmonary venous conduits lump together, as it were, into bigger and bigger conduits; the tiny venules congeal into the bigger veins and this occurs for several generations of conduits until finally all the veins merge together, as if, into the primary pulmonary veins. This (congealing)  is therefore a reverse anatomical movement. A similar congealing can occur in respect of the other conduits. 

Several Ways to Express the Relationship between Entities

 There are several ways in which the relationship between entities belonging to successive levels may be expressed. The higher level entity may be considered as the same as the lower one. Alternatively, the two entities may be considered different. The lower level entity may be considered as only a form of the higher level entity in the light of the underlying philosophy in which an evolute arises due to a rearranging of the particles in the primary matter. Again the primary entity may be viewed as containing within it in potential (unrealised) form all the entities that proceed from it ; which collectively may be seen as making up an entity. And so in this way the primary entity may be referred to by the name of that entity. So there is extreme fluidity when it comes to specifying the relationship between the entities. The constructors of the puranic narratives have made use of such a fluidity and would justify it on philosophico-scientific grounds. Based on different angles of vision the same entity can be considered in different ways. 

For example the entire chariot of the sun may be represented by the bronchi at different levels. Or, the different bronchi may stand only for the (individual) components of the chariot. 

The Concept of "Islands" (dvipa)

The dichotomous branching model of the bronchial tree is utilised by the ancient anatomists to construct a mandala representation in which the primary bronchus (Mt Meru) is placed at the centre. 

The concept of "islands" (dvipa) in the Puranas relates to the anatomical arrangement of the lung. Such an "island" is a lung in miniature--a segment bounded by the “ocean” of the pulmonary vein. These “islands” become more numerous as the airways branch dichotomously.

Bounded by the pulmonary veins on all sides (represented by the bronchi), each segment of the lung is like an island.

 "Jambudvipa" is a region of the lung. "Jambu" is the bronchial "tree" that grows, as it were, on the top of the lobar bronchus.

The bronchi represent the different sides or the directions of and within a particular continent. Each continent is like an island because in whichever "direction" one chooses to travel, one finds oneself surrounded by the "ocean" of the pulmonary vein. All "sides" are bounded or enclosed by the pulmonary vein. It is this fact that is represented in abstracted form in a mandala diagram. Each ocean in reality is a collection of oceans bounding a collection of islands. 

There appears to be a lack of consensus among anatomicians and researchers as to whether the branching pattern of the human bronchial tree is dichotomous or monopodial. The anatomists of the Puranas seem to have accommodated diverse viewpoints. While they seem to recognise that the branching within the bronchial region is quite irregular and varied with a number of peculiar configurations – some of which give rise to interesting metaphors, when it comes to the less discernible bronchiolar region, they have unhesitatingly opted for a regular dichotomous model. And the latter has found expression in the well-known concentric circular diagram of the seven island-continents. 

The Weapons that Pierce

 The weapons that pierce (like spears and arrows) -- nerve fibres acting on the conduits. The slaying (of asuras etc.) by the neural controllers seems to refer to the splitting and bifurcation of the conduits (esp. the p. artery?). The hyaline cartilage seems to act like armature. 

The trident appears to be a symbol for the nerves and the innervating mechanism. Siva's trident pierces the world-elephants. In some images, the trident is shown having lotuses fitted to its ends. This seems to stand for the innervation (piercing) of the bronchial tree. Indra's vajra also seems to be this innervating mechanism. Its association with Dadhici (it was derived from his bones) also strengthens our contention as the rsis are certainly neural entities.

The sun: Determining the Exact Location

 As the sun’s rays cannot spread beyond Lokaloka (the parietal pleura) and as almost the entire primary bronchus lies outside the p. pleura , it seems extremely likely that the p. bronchus does not form a part of the sun. It cannot be the Susumna. In the section on Meru also, we see how the rays of the sun are repelled by the brightness prevailing in Brahmaloka / summit of Meru (p. bronchus). Therefore the sun is imagined by the authors of the Puranas as existing within the lung (enclosed by the pleura). The  primary ray of the sun (susumna) must therefore be the lobar bronchus. 

Cows, Clouds and Respiratory Bronchioles

 The respiratory bronchioles are the cows; (the alveoli are their udder) ; their milk, the flow of oxygen, is collected in the capillaries (vessels).

The respiratory bronchioles are also clouds; as the clouds give rain (flow of oxygen), so the cows give milk (oxygenated blood).

The cow and the clouds in the Puranas both refer to the respiratory bronchiole in the acinar region of the lungs. 

The term "Gokula" or "Vraja" refers to a station of cows and herdsmen. Therefore it is the respiratory bronchiolar region that is given the name of "Gokula" (or "Vraja"). This region is situated at the distal (remote, peripheral) end of the bronchial tree--in the countryside, as it were,--away from the all the larger conduits, the cities and the palaces, where the fine constructions have given way to mere hutments.

Bhu Mandala -- The Region of the Lung

 Bhagavata  Purana 5.16.01

rājovāca

uktas tvayā bhū-maṇḍalāyāma-viśeṣo yāvad ādityas tapati yatra cāsau jyotiṣāṃ gaṇaiś candramā vā saha dṛśyate

The King said:

1. The whole extent of the globe of the earth on which the Sun shines and where the Moon with the hosts of stars is visible, has been described by you.

 "Bhu mandala," the globe of the earth, is code for the region of the lung. The sun, as we have seen, is the bronchus; and the various branches of the bronchial tree together constitute the rays. It is very significant that in this verse, three entities, the sun, the moon and the group of stars are held to mark the region of bhu-mandala.

The pulmonary venous conduit of the lungs is the moon of the Puranas. It is where the "nectar" (amrta) of oxygenated blood flows. 

Like the sun, the moon has also been decoded by us previously. It is the pulmonary vein. In the chapter on the creation and dissolution of the world, we saw how the different components and portions of the circulatory apparatus of the lungs are regarded as the mahabhutas, the gross elements. "Space," or "sky" (akasa) would be the mediastinal segment of the pulmonary artery. This is regarded by the philosopher-anatomicians as the vault or the firmament of the entire apparatus, the supporter of all the other conduits. The stars are supported, as it were, by the firmament and so it must be the collection of pulmonary arterial conduits that are given the code-name of "stars."

The pulmonary arteries are regarded as constellations and groups of stars. Different names are assigned to these groups.