The lymphatic system has been much neglected in most
Western scientific traditions. Contrasted with the heart,
for example, the lymph is relatively unexplored. Perhaps,
because lymph and lymph vessels are generally translucent
they drew little attention in early anatomical study
compared to organs, blood vessels, muscles and bones.
Hippocrates and Aristotle referred to “white blood”
and “colorless fluid” but in the Middle Ages medical
knowledge declined and the lymph was temporarily forgotten.
In 1627 Asellius, in Milan, recovered the knowledge of the
lymph.(38) The structure and action of the lymph system was
still undefined by 1900(39) and the both the immunological
function of the lymph and the actual lymphogenic process are
not clearly understood even today.
In general, the lymphatic system is a network of
organs, tissues,vessels, nodes and flow potentials. It
collects interstitial fluid, infused with the by products of
cellular activity, and transports it centrally where it
rejoins the blood system. In this role it regulates
endogenous metabolites and waste products.(40)
In addition, the lymphatic system is a primary
component of the immune system helping to protect the body
from a broad range of pathogenic factors.(40) It carries
fluids infused with bacteria, virus, fungus into
immuno-active lymph nodes where lymphocytes, reticular cells
and macrophages kill or neutralize toxic or enemy cells,
substances and organisms. In this role it regulates
exogenous disease inducing agents.(40)
The lympatic system also has a nutritional function
wherein it assists in bringing nutritional factors into
proximity with the tissues. This was noted by Asselius in
his original discovery of the chyle filled vessels of a
recently fed dog.(38) In the 1970’s the broad based
nutritional (or trophic) function of the lymph system began
to get deeper exploration.(41)
Like the early medical explorers in Europe, the
founders of Oriental medicine also did not specifically note
the lymph, except non-specifically as a component of the
body fluids.(28,29) However, there is an important
difference between the empirical science of Asia which did
not clearly delineate the lymph and the deductive science of
the West that gave the lymph little note.
In Western science, until recently the nearly
invisible lymph, recieved little of the focus it deserves
and few if any health generating strategies or modalities
were based on its function. In the orient, where science is
based on trial and error and the invisible “Qi” is honored,
the results of healthy and unhealthy lymphatic function were
noted in healthy individuals and contrasted in unhealthy
individuals. Even though the lymphatic function itself was
unknown and unnamed, its effects were generally ascribed to
the proper action of Qi or Prana (energy) and fluids. In
Asia an elaborate system for generating and circulating
lymph was developed through the self care practices of
Qigong and Yoga/Pranayama.
When we look carefully at these practices in relation
to what we now know about lymphatic function and its healing
role it appears as if much of Qi Gong and Yoga/Pranayama
practice were developed specifically with the enhancement of
lymphatic function in mind. Breath, movement and posture all
have specific effects on the production and circulation of
the lymph.
In the West we have divided the body fluids (blood,
lymph, cerebrospinal fluid, synovial fluid, extracellular
fluid, intracellular fluid) into specific categories. From
the paradigm of the west it seems the Chinese may have
overlooked important information with their broad, non
specific view of “Qi, blood and fluids”. However, the lymph
fluid is actually part cellular water and part blood plasma.
The blood plasma is actually comprised, in part, from lymph
fluid.(38) Some of the cerebrospinal fluid finds its way
into the lymphatic system.(42) In this way each of the
individual fluids really make up one fluid. Do we miss
something by the reduction of integrated systems into a
multitude of separate catagories and parts? May we learn
something by simultaneously embracing or, at least
exploring, the more simplified view of the Asian
traditions?
Qi Gong and Yoga/Pranayama practice appear to activate
a number of mechanisms associated with the lymphatic
system:
- Lymph generation
- Lymph propulsion
- Immune function
- Cerebrospinal fluid
circulation - Nutritive function
The actual generation of the lymph has long been attributed
to the filtration of blood plasma from the capillaries (40).
As recently as 1985 this was recognized as the primary
source of the lymph. This idea overlooks a significant
detail that is at the essence of the tremendous health
benefits of Qi Gong. A major portion of the body’s lymph is
produced by the identical physiological process that
generates the body’s chemical energy.(68)
To recapitulate oxydative phosphorylation:
6O2 + C6H12O6 + (BMR) = Ergs + 6CO2 + 6H2O
Six molecules of water are generated for each six molecules
of oxygen that are metabolised in energy production.
In a moderately active 70 Kg human between 2100 and
2800cc of lymph enters the blood stream daily at the
sub-clavian vein through the thoracic duct. Through the
calculations of the Krebs cycle the cells are producing
approximately 950cc (30) of pure interstitial water daily.
In a vigorously active person or one engaging in minimally
strenuous exercise, such as walking, Qi Gong or Pranayama up
to1400cc of aerobically generated interstitial water can be
produced, circulated and eventually passed into the
subclavian vein daily.
Not only is the formula for oxidative phosphoylation
the basis of chemical energy production but it is a primary
source of lymph fluid production as well. Therefore, Qigong
and Yoga practices can increase the amount of lymph which
serves as the fluid carrier for endogenous waste products as
well as exogenous pathogenic factors. In this context the
metabolizing cells are continually contributing pure H2O
into the interstitial spaces.
This water, then, is the vehicle of transport for
metabolic by-products into the lymph vessels. From the
tissue spaces it is propelled, as lymph, to the immunopotent
nodal treatment sites and finally to the elimination organs
via the blood. Increasing body movement and activating the
breath potentially accelerate O2 absorption which generates
more H2O and increases the volume of lymph fluid which
enhances the removal of the by products of metabolism and
pathogenic factors.
The blood circulatory system has the powerful heart muscle
to propel it’s fluid. The lymph, however, under the same
14.7 pounds per square inch of gravitational pressure, has
no distinct heart in humans. The quest for a “lymph heart”
added little to the traditional ideas of propulsion until
the mid 1900’s when studies of birds and reptiles revealed
specific lymph hearts.(43). In humans, however, the
propulsion of lymph was found to be carried out by an
assembly of several mechanisms. The movement of lymph
against gravity is accomplished with the help of a system of
vessels that are liberally equipped with one way valves. It
was known that the lymph was somehow pumped forward and
upward enabling the valves to prevent it from flowing back
with gravity.
Even as late as 1941 several important aspects of the
lymph heart concept in humans remained obscure.(44) By 1949
spontaneous intrinsic pulsatory contraction of the
peripheral lymphatic vessels was demonstrated in humans with
a rythem unassociated with either the heart or the
breath.(45,46) This intrinsic contractility mechanism of the
peripheral lymphatics was seen by many as the long sought
after lymph heart.(40)
The subject of the lymph is complex and very much
unsettled. The current literature is crowded with a wide
range of questions raised by research. What factors might
stimulate the intrinsic contractile mechanism, what
regulates lymph protein concentration, what effect does
passage through the lymph nodes have on the proliferation of
immune cells from within the nodes(47) and what is the
nutrative role of the lymph(41) are several such
questions.
Due to the excitement over the intrinsic pumping
mechanism, the effect on the lymph of one of the classic
propulsion mechanisms, the activity of the respiratory
apparatus, was eclipsed. The breath, through two mechanisms,
has a significant effect on the propulsion of the lymph: 1).
aerobic production of water and 2). mechanical pumping of
the breath apparatus. These will likely gain recognition as
primary components of the multiple features of the lymph
heart. A number of additional propulsive mechanisms are
initiated by body movement and body posture.
Tentitive agreement exists on at least five mechanisms
for accomplishing the propulsion of the lymph that are
stimulated by Qigong and Yoga practices. These include:
- aerobic production
- intrinsic smooth muscle contraction
- movement of striated skeletal muscles
- gravity
- mechanical shifting of pressure gradients in the
body cavities.
a. Aerobic Propulsion–
The aerobic production of lymph contributes to lymph
propulsion by the cellular production of water as a
by-product of oxygen metabolism. The liquid holding capacity
of the tissue spaces is naturally limited. As the limit is
reached, the presence of additional lymph drives the excess
into the smooth muscle vessels of the lymphatic
system.(39,40,43,47)
In Qi Gong this mechanism is triggered by the
coordination of the breath with gentle movement which
increases oxygen demand in the cells. In response there is
an increased availability of oxygen which fuels chemical
energy productivity and consumption. The resultant
contribution of water as a by product increases tissue fluid
volume and drives the overflow into the vessels to become
lymph.(42)
It is noteworthy here that in Traditional Chinese
Medical theory it is taught that the “lungs regulate the
water passages”(48). To students from the west this seems
quite unusual and unfounded. However, we here can see that
the lungs and the breath both produce and circulate the
water in the body.
b. Intrinsic smooth muscle
contraction: autonomic propulsion-
The automatic response of the smooth muscle tissue of the
peripheral lymphatic vessels is to contract when filled and
stretched to a certain tolerance.(46) This moves the lymph
along in the vessel with the assistance of the one way
valves in much the same way as the heart moves the
blood.(42)
In Qi Gong and Yoga this mechanism is triggered by the
breath’s contribution to lymph volume, as well as the
elevation of interstitial pressure caused by the postures
and the movement of the extremities. In addition, this
mechanism may be accelerated or enhanced by the shift of
autonomic function in the relaxation state that is a feature
of Qigong and Yoga.
c. Striated Skeletal Muscle: voluntary
propulsion-
Even the slight movement of skeletal muscle in a
sedentary individual propels the lymph in the one way
vessels. In an active person the lymphatic pumping of the
striated skeletal muscles is greatly multiplied. The effect
of muscle contraction on lymph is one of the classic
explanations for lymph motion.(40,42) In Qi Gong and Yoga
this mechanism is triggered by both the mechanical action of
the musculature of the breath apparatus and the action of
the skeleton through the relaxation and contraction of the
striated muscles in the moving forms of the practice.
d. Gravitational
Propulsion-
Because gravity exerts such a substantial force and because
lymph has so far to climb to get to the thoracic duct’s
entry into the sub-clavian vein any inversion of the limbs
or even the prone body position allows for a free flow of
lymph unencumbered by the effects of gravity. Elevation of
the lower limbs is often prescribed for health problems
characterized by a pooling of interstitial fluids.
In Qi Gong and Yoga the thousands of different
postures and forms, including lying prone and motionless,
often create this mechanical dynamic where the lymph is
actually propelled centrally by gravity. In many methods of
Qigong there are postures and movements that invert the
limbs. In certain walking forms the practitioner is
constantly but slowly moving all of the limbs in beautiful
circular motions that recurrently activate this mechanism.
In Yoga many of the assanas (postures) invert the limbs. In
the head and shoulder stands the whole body is inverted.
e. Breath Apparatus: Mechanical
Propulsion–
The most powerful of the multiplicity of mechanisms
that work together to form the “lymph heart” is the
mechanical action of the breathing apparatus itself(43). The
concentration of lympoid tissue just above and just below
the diaphragm is many times more dense, and contains greater
fluid volume, than any of the lymphoid tissue at the
periphery, or even in the moderately prolific lymphoid areas
of the axilla or groin.(40) Lymph that has been carried from
all over the body accumulates centrally and is then
propelled by the breath/diaphragm in a final rush through
the thoracic lymph duct into the blood at the sub-clavian
vein where it leaves behind its identity as lymph and is
transformed into blood serum.(49)
Above the diaphragm the thoracic duct of the lymphatic
system is a central collecting vessel. Its size is many
times that of a peripheral lymph vessel. Below the diaphragm
a substantial dilation of the thoracic duct forms a
collecting capsule for lymph, called the “cisterna chyli”
(cisterna=cavity, receptical or reservior) Chyle is a milky
fluid infused with nutritional factors absorbed from the
small intestine by the lacteals, which is passed into the
circulating blood through the thoracic duct. The fluid that
fills the cisterna chyli is a mixture of the nutrient rich
chyle from the lacteals and the lymph that carries the
metabolic by-products from the tissue of the organs, muscles
and glands.
When full inspiration of the breath occurs, the
diapragm drops downward and a tremendous negative pressure
is generated in the thoracic cavity. As air rushes into fill
this negative pressure the lungs are fully expanded. This
compresses the thoracic duct. Due to the one way nature of
the valvular system lymph is forced upward into the
sub-clavian vein.
Simultaneously, when the diaphragm drops downward on
full inspiration it compresses the abdominal and pelvic
organs including the cisterna chyli which empties under the
pressure. The contents of the lymphoid reserviors and
vessels are forced by the same one way system of valves
upward toward the thoracic duct. In research done by Dr.
Jack Shields (49) moving X-ray films were used to study
subjects in various actions and breath patterns. It was
demonstrated that deep inspiration pumps the lymph at a rate
that is dramatically increased over average resting
inspiration and other activities.
The immunoactive aspect of the lymphatic system is well
represented in the literature.(42,44,47,50) The bone marrow,
thymus, spleen and lymph nodes participate in the
interaction of the lymph and immunity. The composition of
the lymph fluid itself includes a number of immune active
agents such as lymphocytes and macrophages.(47)
Lymphocytes that exit with the lymph fluid from the
nodes come from three sources: 1) inflowing with lymph from
the tissues in the peripheral vessels, 2) exchanged from the
blood that enters the node’s own vascular system and 3)
formed by local proliferation in the node itself.(42)
Lymphocytes naturally collect within the node, especially
when flow is sluggish. Greater numbers proliferate when
lymph flow is greater and the numbers circulated out of the
node increase with flow volume as well.(42)
Excellent recent research has clearly delineated,
localized and quantified the development of specific
antibody forming cells in lymph nodes.(50) In addition, it
has been found that there are neurotransmitter receptor
sites on lymphocytes where they actually interface with
neurotransmitters.(51) This demonstrates an important link
between neurochemistry and immunity through the medium of
the lymph system.
The cerebrospinal fluid (CSF) system has classically been
perceived as a closed system. One view held that CSF was
actually in an open system that allowed the fluid to flow
through the aracnoid villi and into the venous blood.
However, by the 1970’s it was generally acknowledged that
the CSF travels along the cranial and spinal nerves and into
the perineural lymphatics.(52)
Some recent research using the microinjection of
tracers has suggested several possible pathways for the
passage of both the CSF and the cerebral interstitial fluid
(CIF) to exit the aracnoid space.(42) By 1985 the flow of
CSF and CIF into the lymphatics was well documented.(42)
Consideration has even been given to the effects of pressure
and posture on this flow(42), both of which are primary
effects that are enhanced in Qi Gong and Yoga/Pranayama
practice.
The presence of CSF in the lymphatic system and the
presence of neurotransmitter receptors on immune cells(53)
suggestes a powerful association between neurotransmitters
and immune function in the reticuloendothelial system. While
the effect of Qi Gong and Yoga/Pranayama on this mechanism
is not clearly defined, it is likely that it occurs through
lymph propulsion as has been discussed. Research to quantify
and delineate this aspect of the lymph system and explore
the action of lymph and CSF as a transport system for
specific neurochemicals is clearly a priority.
5. Nutritive
(trophic) Function
The importance of a broad availability of nutritional
factors to the tissues is fully accepted. However, the role
of the lymphatic system in this activity was barely
understood before 1972.(41) The original findings of
Assellius in dogs revealed the route of absorbtion of
nutrients from the small intestine via the lacteals.(40) The
effect of the breath apparatus through the action of the
diaphragm, during deep inspiration, on the cysterna chyli
and the small intestine may enhance the rate or
effectiveness of nutrient absorbtion. This may be an
especially important mechanism in the absorption of
nutritional factors and the delivery of the pharmacologic
potential of herbal formulas that are commonly used in both
the Chinese and Indian traditional medical systems.
In addition, free extracellular proteins participate
in lymph fluid and as plasma protiens in the blood. They
carry constituent amino acids that may be utilized by the
tissues. These may become conjugated protiens which carry
essential minerals, fats, carbohydrtates and enzymes to
their respective destinies.(41) The clarification and
understanding of the trophic function of the lymph suggests
a simple but profound effect of the enhanced lymph volume
and flow rate activated by Qigong and Yoga/Pranayama.
©1996 Roger Jahnke,
O.M.D.