THE LIVING BEING AS A COMPLEX SYSTEM OF FLUID MECHANICS
PULMO-CARDIAC VISCERAL CIRCULATORY SYSTEM FOR AIR AND BLOOD CIRCULATION LEADING TO RESPIRATION
Lung. Heart and their nets of passages for
their respective fluids, air and blood, circulation, obey a
common organic-functional conception leading to simultaneous
transportation of their specific fluids for pulmonary and cells
gas exchange or respiration, to maintain Created Life in a
permanent metabolic dynamic balance. They constitute an
integrated mechanical functional dynamic unit, a Mechanical
System of Fluids, where actions and reactions in each sector are
synchronised for their complementation at every moment.
This complementation of visceral actions and reactions also involve, reflex via, the dynamic-functional structure of the thorax and abdomen walls.
The overwhelming areas for the Pulmo-Cardiac Circulatory System dynamic integration can be featured as follows:
I. SURFACES FOR SPECIALISED SERVICES or ports for materials delivery and exchange.
The circulating arterial blood finally delivers its load of materials throughout its finest branches or capillaries, where red cells, loaded with Oxygen circulate in a line for their discharge; consequently, the capillary net must embrace the totality of the tissues.
Once these red cells have discharged their Oxygen load and the blood collected metabolic waste, follow their circulation towards the other port of gas exchange, the alveolar-capillary surface, to then continue for a new cycle.
The loading and discharge of Oxygen by red cells contained in similar volumes of blood circulating throughout the two opposed functional surfaces is accomplished synchronically, to allow for local and general dynamic balance. For the same reason, the alveolar-capillary surface is similar or proportional to the tissues capillary surface.
The oxygen load at the alveoli is an undifferentiated general fact. Therefore, the alveolar surface, as a port for delivery and loading can be compacted in small volumes; from here the organic Design comprising five (5) lobes as the greatest independent and integrated pulmonary mechanic-functional units. The Lung's division into lobes means a first division and distribution of work and materials.
The oxygen load at the alveoli and its delivery at the tissues, by similar volumes of blood circulating along the two opposed surfaces is simultaneous and continuous, as a guarantee of the organic fluids general dynamic balance. Consequently, this is a reason for the existence of two ventricular pumps, which must simultaneously eject two similar fractions of the total circulating blood towards the two named opposite destinations.
II. PULMO-CARDIAC ALVEOLO-CAPILLARY INTEGRATION.
The volume-mass of alveolar capillary blood, ejected by each systole of the right ventricle, demands a simultaneous presence of a similar or proportional volume-mass of alveolar air. Therefore, the necessary presence of tiny pulmonary pumps for local division and distribution of the air mass into the lobuli, to achieve simultaneous arrival of the small volume-masses of air into each one of the alveolar units.
Balanced air and blood volume-masses are guaranteed by organic design; thats to say, by the functional potential capacities of the respective pumps and passages. Besides, the integrating nervous command is guarantee of synchrony and intensity, of the cyclic nervous discharge to perform muscular contraction, chronotropic and inotropic effects, generators of the simultaneously needed forces and capacity variations of Heart ventricles, blood vessels and airways.
We must bear in mind, as I have said apart, that the unitary pumps that eject the alveolar air mass are the lobuli or dynamic-functional smaller mechanical units, designed for immediate ejection and distribution of the air into the alveoli. The alveoli are only specialised surfaces for selective diffusion of gases during gas exchange with the blood.
The cyclic simultaneity of these complex facts, which must achieve a predetermined result at the alveolar-capillary units demands, a perfect net of proportional Parasympathetic and Sympathetic nerve fibres distribution, also complemented with reflex mechanisms, as a guarantee of the Heart and Lung's-lobuli dynamic integration. This role at the lobular-alveolar-capillary level is accomplished by the thoracic Sympathetic, co-ordinated by the Vagus discharge, both under the Central Nervous System control.
III. VOLUME MASSES OF AIR AND BLOOD.
Another important concept to take into account is the physical concept of volume-mass, relative to gases contained into variable capacities, to be applied here to simultaneous masses of blood ejected by each ventricular systole, right and left, (x) in relation with the total volume-mass of blood (X). This latter must fill out arterial and venous vessels, to keep circulation uniform and balanced. The former relationship can be expressed as follows: X/x, which means the number of cardiac cycles, needed to displace the total volume of circulating blood.
In a similar way we can consider the volume-mass of air ejected by each contraction of the lobular bronchioli (y). ("Systole" by analogy) and the volume-mass of air filling the total capacity of the pulmonary (lobar) airways (Y) to keep uniform and balanced the intra-pulmonary circulation of air. This relationship can be expressed as Y/y, which means the number of lobular alveolar-capillary cycles needed to displace the total volume-mass of air filling the pulmonary airways.
I emphasise and repeat the physical concept of volume mass, because understanding of the new interpretation of Respiratory Dynamics demands the correct management of this concept, since Respiration is accomplished with volumes of atmospheric air, from which the tension of gases is relative to gravitational force, at the level of the individual adaptation.
Now: lobuli and alveoli demand specific physical conditions of the circulating air, to be appropriated for pulmonary respiration, and these conditions are different to those of atmospheric air. Therefore, this latter must be successively physiologically acclimatised, humidified and pressurised into the different segments of the air-passages, from the nasal fossae and Pharynx up to the respiratory bronchioli before being delivered to the alveoli, where the "organised" mass of air must balance capillary blood. On the other hand, blood is a tissue in liquid state, as tissue does not need to be adapted and as a liquid is not compressible, its volume-mass is theoretically constant. Therefore, its volume-mass does not change under the action of forces applied to it, as in the case of systole and diastole, it is only the speed of circulation and final pressure that change.
This very complex and fine visceral dynamics would be mechanically over stressed if the organism does not dispose of somatic structures for physical assistance. This somatic structure is mainly an assistant of the pulmonary elastic structure, being controlled by the proper Lung, via a visceral-somatic reflex: the pulmo-diaphragmatic reflex, which also unchains a series of somatic-somatic reflexes to dynamically, incorporate the thorax walls. Therefore, The Lung as effector of the Vagus-Sympathetic nerve is leader of the whole Respiratory Dynamic Cycles,
IV. BLOOD IS AN ORGANIC TISSUE, WHILE ATMOSPHERIC AIR IS AN INORGANIC MIXTURE OF GASES.
Blood is a tissue. Therefore, it must be put into circulation throughout a closed circuit, as much for renewal of the transported gases as for their delivery to the cells.
V. ALVEOLAR AIR IS "ORGANISED" AIR.
Intra-pulmonary air is a physiologically acclimatised and pressurised mixture of gases. Therefore, it becomes an "organised" mass of gases derived from the atmospheric air. These concepts added to others exposed above put into evidence the physiological role accomplished not only by the Lung but also by the extra-pulmonary airways, which are not simple passageways, as I have demonstrated apart and resume here.
The main bronchi, right and left. Trachea and Larynx closed by the Glottis, constitute a specific working segment of the whole circuit, which functions to receive the masses of warm air used by fractions during the period of the cycle just finishing, which fills up the upper part of the Tracheo-Larynx before being ejected towards the Atmosphere at the very beginning of the Glottis relaxation. "Expiration" strictus sense. This ejected air folows towards the Atmosphere as a stream of warm air, being replaced by an opposite stream of fresh air coming from the Atmosphere.
The air ejection towards the Atmosphere is simultaneous with intra-lobar air ejection towards their periphery, thus creating a backwards relative vacuum to aspire the air stored and acclimatised into the right and left main bronchi, since the former cycle, (Lobar "Inspiration"). This fact creates a similar force to aspire the air in the naso-Pharynx, which also becomes an air exhausted cavity to be filled with atmospheric air, for storage and adaptation during the starting cycle, and following next cycle towards the main bronchi.
The Naso-Pharynx consequently constitutes the upper segment of the airways as a whole, being the only one in direct relationship with the Atmosphere. Naso-Pharynx is a passage way for the used air ejected from the Tracheo-Larynx, also offering to this latter the air mass retained from the former cycle, now with a first degree of acclimatisation, this provides the physical conditions for aspiration of a new atmospheric air mass.
This load, temporary storage and processing "Organisation" of atmospheric air, to be delivered to the pulmonary lobes, jointly with ejection of the air used during previous lobular respiratory cycles is performed in stages, where each sector accomplishes its own role.
Summing up: Each different sector of the total airways is, consequently, a partial circuit for cyclic temporary storage and reserve of atmospheric air, while receiving successive degrees of acclimatisation and pressurisation, "Organisation" to enable the alveolar role in Respiration. Think, at least for a moment, about the organic stress that would mean our direct and permanent dependence on the atmospheric air in its inorganic conditions.
Return to Scrutiny of The Living Beings Self Making