The heart's two blood circuits

In the human heart, two blood circuits meet, a minor and major blood circuit. The rhythmic heart and lungs mediate between these two circuits:

the minor circulation connects with the brain and nervous system (sensory impressions)
the major with the organs and metabolic system (food stuff)

The lungs are intermediate between the oxygen (inhalation) and carbon-dioxide (exhalation) in the blood (see Schema FMC00.157 below)

Aspects

the arterial blood does not immediately goes over there into the veinous blood: a fine flowing out and again an absorbtion takes place. In what takes place as the outflowing vibrates the rhythm of circulation and in the nerve adjacent to it, the rhythm of the respiration vibrates really in these two rhythms which hit into each other. (1922-10-20-GA218)
the layout of the two blood circuits and the four heart chambers can be mapped to the spiritual streams around the Sun, see Schema FMC00.034 and the Discussion note: Sun#Note 1 - About Schema FMC00.034
through the two blood streams, the heart merges both impressions from the senses, and mineral impressions from the metabolic systems. In the Holy Grail, this concept is covered on the Ganganda Greida page, see Schema FMC00.354 (also explained on Kundalini)
on the fourth apocalyptic seal - see Schema FMC00.228 below - the red oxygen-rich blood and blue carbon-dioxide-rich blood are represented in the two pillars labelled J and B where they represent the trees of Knowledge (blue blood, death, B) and the tree of Life (red blood, J) - see more on Golden legend
See also: Ganganda greida

Inspirational quote

Rudolf Steiner:

The Christ mystery is the revelation of the great miracle that takes place between the heart and the lungs. The cosmos becomes the human being and the human being becomes the cosmos.
The Sun carries the human being out of the cosmos and onto the Earth. The Moon carries the human being from the Earth into the cosmos. In larger terms, what streams from the lungs to the heart is the human correlate of the descent of Christ onto the Earth; what moves from the heart to the lungs is the human correlate of the human being carried into the spirit world by the Christ impulse after death.

Thus the secret of Golgotha lives between the heart and the lungs in each human being, in a very human, organ-related sense.

For a commentary, see Note [1] in Discussion area below.

Illustrations

Schema FMC00.157 illustrates the blood circulation through the upper four organs (Holtzapfel, see also Spiritual scientific physiology)

Schema FMC00.034 shows a mapping of the organs in Man's spiritual scientific physiology and the Sun-Earth-Moon constellation. The form layout of the heart with the two circuits (see drawing right) can be mapped to the Earth between Sun and Moon (see middle drawing).

Notes:

Compare the above with the notebook entry lower right of FMC00.339A on Rudolf Steiner's Gesamtausgabe (GA). See also Discussion note Sun#Note 1 - About Schema FMC00.034
regarding links with Sun and Moon streams, see eg also Schema FMC00.542 below and on Working of substances and their forces
For more on references to Man as linked to Sun and Moon, as per the Emerald Table, see also how this relates to the two etheric streams .

Schema FMC00.034A shows the symbolism of the form in the layout of the first Goetheanum in Dornach, with the heart in the center of the two circles. The Representative of humanity was placed in the small circle above. Compare with Schema FMC00.034.

Schema FMC00.542 illustrates the process of breathing air and the two streams of oxygen and nitrogen combining with liquid carbon in the human body and giving rise to processes generating carbonic acid and cyanic acid. Click twice and open in new tab to enlarge.

from the intake of oxygen (remnant of the separation of the moon): the carbonic acid stream 'flows up' to combine with sodium and iron to carbonic iron (and links Man to the moon); this is why 'soda in the head-nerve subsystem' is linked to thinking.
from the intake of nitrogen (remnant of the separation of the Sun: the cyanic acid stream 'flows down' to combine with calcium oxides (lime) to generate cyanide (and links Man to the sun); this links to the limb system and willing.

Note this schema focuses on the stream of coarse breathing of air as part of the middle rhythmic subsystem of Man. The silica and calcium processes (see above head and below the figure) are polar opposites related more typically to the head-nerve and metabolic-limb systems, though these processes work in the whole human body and affect all three subsystems (see 1921-04-11-GA313 and 1920-03-29-GA312 and other schemas).

Schema FMC00.180 (from Olive Whicher) shows an etheric perspective on the heart (left), connecting it with the image of 'Man as an inverted plant' (right - see also Schema FMC00.110 on Man as a threefold being ). The middle drawing represents the area between two focal points with the heart above and the brain below. See more on: Etherization of the blood

Schema FMC00.228 shows on the left, the fourth apocalyptic seal with the two pillars J and B representing (red and blue) the Trees of Knowledge and Life. The blue tree clearly knowledge with the linked book and standing on physical earthly ground, the red tree clearly upstreaming life. Two pillars supporting earth’s development: Jupiter and Mercury, Old Sun and Moon, Strength and Wisdom.

See 1907-10-GA284 about the pictures of the apocalyptic seals and columns (as well as more references in that volume GA284 about the symbolic meaning of the colours blue and red in 1911-10-15-GA284, and more).

On the right, a Freemason Rosicrucian illustration dated 1779 (taken from 'The Freemason by Eugen Lennhoff, published 1913). See also the alchemical symbols of earth below B, and air below J

Lecture references

1911-03-21-GA128

1914-07-05-GA286

is the reference for the spiritual streams around the four chambers of the spiritual Sun, see Sun#1914-07-05-GA286

1920-05-15-GA201

Consider for a moment the circulation of the blood. The blood, transmuted by the outer air, enters the left auricle, passes into the left ventricle, and from thence branches off through the aorta into the organism.
We can say: Blood passes from the lungs to the heart, thence into the rest of the organism, but branching off also to the head.

The blood however in passing through the organism takes up the nourishment. And into this is introduced all that is dependent on the Earth. All that the digestive apparatus introduces into the circulation of the blood is earthly.

What is introduced through the breathing, when we bring oxygen into the blood-course, is planetary.

And then we have the blood-circulation that goes to the head, which includes all that composes the head. Just as the circulatory course of the lungs with its absorption of oxygen, and giving out of carbonic acid, belongs to the planetary system, just as what is introduced through the digestive apparatus belongs to the Earth, so that part of the circulatory course that branches off above, belongs to the starry world. It is, as it were, drawn away from the aorta and then streams back and unites with the blood streaming back from the rest of the organism, so that they stream conjointly back to the heart. That which branches off above says, as it were, to the whole of the rest of the circulatory course: ‘I do not share either in the oxygenating process nor in the digestive process, but I separate myself out. I invert myself upwards.’ That it is that belongs to the starry world.
And the nervous system might be followed up in the same way.

1922-10-20-GA218

It is not as coarse as one generally presents it; instead it is so that the arteries of the blood have their own course and the veins join in again (diagram red), so that not one also loins the other. In the eye especially, the artery runs so that the blood flows out so to say, and is there only then absorbed in turn by the vein, so that a slight flowing off and a re-absorbtion comes about in the eye.
It is an entirely false and coarse view, if one believes that arterial blood immediately goes over there into the veinous blood. It is not so.
A fine flowing out and again an absorbtion takes place. In what takes place as the outflowing vibrates the rhythm of circulation and in the nerve adjacent to it, the rhythm of the respiration vibrates really in these two rhythms which hit into each other.
Imagine these two rhythms were alike, then we would not see.

1923-09-14-GA228

The form also corresponds to the layout of the Goetheanum and the Druid stone circles near Penmaenmawr in Wales, as Rudolf Steiner points out in when describing the particular geographical qualities of a specific location and the astral atmosphere in 1923-09-14-GA228:

You come to realize how these old Druids chose for their most important cult-centers, just such places in which the spiritual as it approaches mankind, expresses itself to some extent in the quality of the place. Those Druid circles we visited — well, if we had gone up on a balloon and looked down from above on the larger and the smaller circles, for though they are some distance apart you would not notice that when you are a certain height above them — the circles would have appeared like the ground-plan of the Goetheanum which has been destroyed by fire.

Olive Whicher goes into this in her book 'Sunspace'.

For more on the Legend of the Tree of Life and the Tree of Knowledge, see 1915-12-27-GA165 (and 1915-12-18 and 1915-05-30 and more in GA165), 1905-05-29-GA093.

Discussion

Note 1 - Commentary on: "the secret of the MoG takes takes place between the heart and the lungs"

Once again the full quote:

Blood in the heart, striving toward the breath in the lungs, is humanity's striving for the cosmos.
The breath in the lungs, striving toward the blood in the heart, is the cosmos forgiving humanity.
Blood striving for the heart is the refined process of dying. The blood, carrying carbon dioxide out of the body, is portraying the refined process of dying.
The human being streams into the cosmos on an ongoing basis in the flow of the blood. This is an event that shapes itself radically after death by seizing the entire physical being through the blood....
The Christ mystery is the revelation of the great miracle that takes place between the heart and the lungs. The cosmos becomes the human being and the human being becomes the cosmos.

The Sun carries the human being out of the cosmos and onto the Earth.

The Moon carries the human being from the Earth into the cosmos.

In larger terms,

what streams from the lungs to the heart is the human correlate of the descent of Christ onto the Earth;

what moves from the heart to the lungs is the human correlate of the human being carried into the spirit world by the Christ impulse after death.
Thus the secret of Golgotha lives between the heart and the lungs in each human being, in a very human, organ-related sense.

Consider Schema FMC00.034 to 'read' the above, maybe the few lines can help your contemplation: Man - Earth - lungs, Christ - sun - heart.

'the sun carries Man from cosmos to Earth' means that the major blood circuit allows Man to function on Earth thanks to cosmic influences and metabolic transmutation that are circulated in that major circuit.
'The moon carries Man from earth to cosmos' means that the minor circulation carries the sense impressions, and through living Man participates on earth and matter disappears in the brain and these fruits of Man's life will ultimately be brought to the cosmos.
'What streams from lungs to heart is descent of Christ to earth' means that Man breathes in, with fine breathing, the higher ethers.
'What moves from heart to lungs is like Man's return to spirit world after death through Christ impulse' is the out-breathing whereby Man is returned to the spirit world with all fruits of his life, but now in the image of a single breath or the breathing process.

Last, see also related: Mystery of the Heart#Note 1 - The heart as the center

Related pages

References and further reading

Heinz-Hartmut Vogel: 'Blut und Lymphe : entwicklungsgeschichtliche und morphologisch-pathologische Phänomene zum Verständnis der Kreislauferkrankungen und ihrer Therapie' (1967)
Wolfgang Schad: 'Dynamische Morphologie von Herz und Kreislauf' (Goetheanistische Naturwissenschaft Band 4 Anthropologie, 1985, Seite 190–206)

Olive Whicher: 'Sunspace'
Werner Christian Simonis: 'Herz- und Kreislaufstörungen im Spiegel ihrer Heilmittel' (1988)