Interdependence Between Structure and Function

Dr. Teresa Battaglia

physiotherapist - osteopath

Man usually lives in upright position; only illness or rest forces him to lie down. His pathologies cannot be analyzed without considering this reality and the importance that statics and postural attitude play in life.

How often does an individual feel bad in his body even though diagnostic or instrumental tests are completely negative? It is necessary to question this and try strategies that, beyond general or specific symptoms, also consider the postural causes (visceral, craniosacral, structural, tissue, organic, or others) that caused the onset and development of the anomaly.

To achieve good results, it is necessary to internalize functional anatomy and physiology, and insert them into an interdependent global concept. Converging our knowledge in this direction, it will be found that many pathological situations are the result of postural imbalances that, due to a succession of events whose structural modification of tissues, have altered their function.

The philosopher Claude Bernard states: "function creates the organ and the organ adapts to the function; in physiology function governs form, while in pathology it is form that governs function."

Françoise Mézières says: "in a healthy body function governs structure, in a sick body structure governs function. Just as the ear recognizes the right notes from the wrong ones, the eye must distinguish healthy form from dysmorphic form."

Similarly, A. T. Still (1828 - 1917), founder of osteopathy, proclaims: "structure governs function and function induces structure."

Functional anatomy aims to study the relationships between structure and function of the anatomical part under consideration. Functional anatomy starts from the anatomical description of a specific structure, muscle, or organ defining its anatomy and is interested in the functioning of that structure, indicating, for example, for muscles their functions and how they work.

The term Structure derives from the Latin structura, from struĕre "to build, to pile up" (past participle structus). Broadly, it means the constitution and distribution of elements which, in correlation and functional interdependence, form an organic complex or a part of it; the complex itself, or a component of it, understood as a functionally unitary entity resulting from the reciprocal relationships of its constituent elements. In biology, the composition and arrangement of the parts constituting a tissue, organ, or an entire organism; we speak of macroscopic, microscopic, submicroscopic (or ultramicroscopic) structure, depending on whether it is observable without magnification, with an optical microscope, or resolvable with more powerful instruments, such as the electron microscope. Also, the relative arrangement of atoms in a molecule and of molecules in more complex ones (DNA structure, hemoglobin structure, etc.). Broadly, especially in common language, the set of parts that contribute to forming the human body or any other animal organism, and therefore also its constitution and conformation.

The term Function derives from the Latin functio-onis, derived from fungi «to perform». Activity habitually or temporarily performed for a specific purpose, mostly considered within the context of a social or bureaucratic system. In physiology, the activity proper to a cell, or part of it, or an organ, or an organic system.

It is now undisputed that there are close relationships between form and function; however, it is not always easy to demonstrate this due to the multiplicity of factors intersecting in determining anatomical structure. In fact, when various functions coexist in the same structure, such as in the stomatognathic system, it is necessary to translate the same functions, anatomically-functionally into various substrates, in order to reconstruct the global functional aspect of the individual elements. Therefore, it can be stated that there is a close interdependence between structure and function; this leads to observing the body as a dynamic functional unit, possessing characteristics of relation and integration. Therefore, there are timings, that is: in the growing child who must occupy space, function models structure. In the adult there is the true ergonomic phase, with function and form being equivalent. In the elderly the form is inadequate to that function and the same function implodes the form, destroying it.

If an organ is made a certain way, its function helps us understand why. Even though it is generally believed that there is no stable and fixed anatomical form reflecting a definitive equilibrium between structure and function.

If we consider posture as the result of the dynamic interaction between two groups of forces: gravity force opposed to the individual's force, then posture is nothing but the form in which the balance of power existing at any moment between these two groups of forces is expressed. Therefore, any deterioration in posture indicates that the individual is losing ground in his struggle with the environmental force of gravity.

The body is an aggregate model with its own median; gravity presses on this model tending to crush it with a centripetal force. Therefore, man is subject to centripetal forces (implosive, like the force of gravity) and centrifugal forces (explosive, like the need to move). Disease and aging are associated with reduced movement and an increase in centripetal forces. Anything that disturbs movement is an increase in centripetal forces (less space). The form of man is the best resultant transmission of centrifugal forces at that moment.

Anatomy is a logical consequence, where forms depend on functions. There can be no form without a function, function models form and models it ergonomically; in ergonomics form simply reflects a limited directional choice possibility. So it becomes a specialization.

Function is born before form, first there is Energy, then Matter. Matter is a condensation of Energy, which cannot prevail over Energy. Therefore, function is linked to Energy that chooses directions that respect the right Time, right Speed and that occupy the right Space. This is the physiology of a living system, which models forms and must meet the functional needs of that district. Ergonomics, precisely, consists of: that form for that function. So the eternal dilemma between interdependence between form and function is not equivalent but there is always an imbalance in favor of function that can simplify form. So form is unstable while function remains stable.

Complexity arises from the organization of a system, and in the same system structures that perform complex functions in toto cannot be created. Therefore, it is necessary that each global movement can be fractionated into many parts and each segment is assigned a certain type of work. These works respond to the law regulating vector factors: Speed, Space, Time. Function is the expression of a movement and is made to move matter in a certain direction, speed and time. Speed, space and time are vector quantities, intimately connected. If I move one, the others also change.

• The ideal conditions in which our body performs its functions are: 

• Right Speed
• Right Space
• Right Temporo-mandibular;

these three equivalent parameters produce Health, aimed at ergonomics;

• Dysfunction is a condition that acts and modifies vector quantities, because it will have to create trajectories that deviate from ergonomics: 
  • it will increase Time, 
  • decrease Speed and occupy more space, different from ergonomics 
    • • which will require: 
  • greater energy expenditure.

• Fixation is a situation that I cannot modify and will be a condition of stasis, of equilibrium in a dynamic system:
  • denial of Time, 
  • denial of Speed 
  • denial of Space

Still (founder of osteopathy) said that from birth we are endowed with an energy potential, which is the energetic quid that always accompanies us and does not change. But there are many dysfunctions, the energetic response capacity is greatly impoverished and makes living difficult.

"The quality of life depends on the quality of movement." A.T. Still.

Functions manifest with forward and return mechanisms, they show through a direction that can be centripetal, inward, or centrifugal if going outward. For example, respiration is half centrifugal flow and half centripetal, establishing equilibrium. Same for the digestive system: half centripetal and half centrifugal. Same for the circulatory system: half systolic process and half diastolic.

If this applies to the main macrosystems, joints are also subject to mechanisms that have a forward and backward movement to a resting position. This alternation must find an intermediate point of non-action, identified as a median. However, inside there are multiple forward and backward movements, which create a wave motion, resulting in a unique resultant. This resultant is always found at the moment of least oscillation possible in an infinite number of medians. In our system coexist an infinite number of medians, which have a single resultant which is verticality. Around this quiet fulcrum we have oscillations that allow us to cross it but not to stop at the stability point. Therefore, oscillation and asymmetry are part of human nature.

The postural system is oscillatory and not static. In a dynamic system there cannot be a moment of static quiet. Phases of action and non-action find moments that reduce action but cannot interrupt it. This is the characteristic of life, which makes a vital system different from an inert one, which can reach an equilibrium situation. While we do not respond to thermodynamic laws, our organization at every moment must readjust the mechanism of order seeking against environmental perturbations.

In conclusion, to have movement the first thing needed is Energy, then Mass, Organization, Function. Forces must be organized to dissipate as little as possible; ergonomics is needed and all this provides an anti-gravity response. The medians: energetic, chemical (homeostasis), structural, functional, ergonomic give an anti-gravity response.

Density is the ratio between mass and volume; it indicates the amount of matter that occupies the volume in relation to unoccupied spaces. A homogeneous density presupposes that the distribution of matter is uniform, heterogeneity presupposes that in some points matter is more aggregated in some districts than others. Matter arranges in space or volume passively, under the push of force flows that in their centripetal or centrifugal movement organize its arrangement. The state-dynamic equilibrium lies in the possibility of alternating between the two flows; thus force and material arrangement maintain, despite dynamics, characteristics of pseudostability.

In some cases it happens that the centripetal flow may prevail over the centrifugal one, resulting in the distribution of matter inside the body system being compressed, crushed under the push of forces that cannot reverse the direction of their flow. In this condition the voids present in molecular positions are reduced. The amount of interstitial void is indispensable to exchanges, every exchange requires free occupiable space.

The ratio between the amount of matter and its occupiable space is the indispensable condition for any change of state.

In the absence of free occupiable space, there can be no movement. The centripetal flow on matter densifies the state of matter present in the district conditioning and deviating the forces and surrounding structures. The wound triggers a perverse and unstoppable attractive mechanism that over time will condition the distribution of forces and synergies in the whole system. As happens in the attractive field of a black hole in the universe where matter has undergone a compression collapse, energy remains active and the centripetal flow channels matter toward the central point organizing it in a very high density, since there will be no more free intermolecular spaces.

It is necessary an external force able to interact with the body system in order to obtain a flow inversion mechanism, able both to interrupt the centrifugal trend and to modify the created situation, reorganizing the periphery of the density and producing free space, for the change that favors the dissipation of the organized state of compressed matter.

Any increase in density entails an organization of force flows able to generate an implosive condition for surrounding tissues and a modification of both force and matter flows even in distant districts. Often these functional anomalies manifest with small mobility limitations or increased consistency of local tissues.

These conditions are the litmus test signaling a district difficulty of potential state energies that to perform their work require a directional inversion of flow. Since energy can neither be created nor destroyed, the only system to restore correct exchanges must go through a conversion into other types of energy: kinetic, thermal, electrical, chemical. Energy accumulations and rigid consistencies of tissues become in the body system zones of increased density, where tissues are hindered in their intrinsic ability to communicate, to exchange supply and drainage. These zones represent continuous afferent sources to control systems, without possibility of compensation or redistribution of forces, creating a situation that escapes reorganization, reason why they are excluded with a sort of freezing of the functional ensemble, through a process of local tissue "sideration".

In the continuity of relation between all tissues and systems, what is transmitted to one component, in almost real time, is received by the whole set of systems: 

"In continuity the action is transmitted to the entire body globality."

Bibliography

• Iginio Furlan, Erio Mossi, coadjutor: F. Peyralade “L'organizzazione connettivale, Correlazioni anatomofisiologiche e funzionali del movimento” ,
• ROI Collection   GSC.
• Vittorio Chesi "Dialogo con il movimento. Guida pratica alle Tecniche di ascolto ed induzione in Osteopathy".
• SEID Publishers.
• Treccani Encyclopedia