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.