1 The Foundations of Manual Lymph Drainage in Chemistry, Physics, Physiology and Histology
1.1 The Basics of Manual Lymph Drainage's Mode of Operation
1.1.1 The Autonomic Nervous System
The autonomic nervous system is made up of two subsystems: the sympathetic and the parasympathetic. The active sympathetic energizes us, while the parasympathetic sees to relaxation, resting, recuperation. One can find the fibers of the parasympathetic system in all parts of the human body, including connective tissue.
Normally, the reactive state is in equilibrium. Hectic activity, stress and other external factors increase sympathicotonia. This leads to disharmony, which results in negative states, complaints and ailments. The autonomic nervous system's activity is not subject to our will and cannot be directly influenced by us. Consciousness resides in the cerebral cortex, whereas the unconscious is found in the autonomic centers in the spinal cord and other parts of the brain.
There are two kinds of cells in the central nervous system. The actual organ cells are the ganglion cells, with the glial cells forming the supportive framework. They actively take in nutrients from the blood stream and transport them through their cell bodies to the ganglion cells. Because of their specialized construction, they only take up certain specific substances from the blood and pass them on; this is known as the blood-brain barrier.
Transmission of stimuli takes place via the ganglion cells. Simplifying somewhat, they consist of cell membrane, protoplasm, nucleus, endoplasmic reticulum (protein synthesis), Golgi body and numerous mitochondria for energy production. These structures are an integral part of the cell body.
In addition, a ganglion cell has one or two long extensions (axons) and numerous shorter ones (dendrites).
Fig. 1: Functional diagram of a ganglion cell
A peripheral nerve is composed of a number of axons bundled together. Myelinated nerves are coated with a myelin sheath. Axons can be low-myelin, amyelinic or high-myelin. This is decisive for stimulus quality and propagation speed. Motor and sensory tracts consist of myelinated axons, the nerve tracts are amyelinic.The axon terminates in club-shaped expansions called synaptic knobs, which are surrounded by a presynaptic membrane. The impulse receptors are located in the dendrites, from which the impulses are transmitted to the synaptic knobs. The variously-constructed ganglion cells determine the type of impulse and its transmission. The entire unit is also called the axon. Impulse transmission in this axon is an electrical process. Axon length varies, and can exceed a yard in length.
The synaptic knobs (presynaptic portion) are in indirect contact with the dendrites of the next nerve cell (postsynaptic cell), separated by the synaptic cleft, or synapse. Here various potentials are formed of a chemical or electrical nature. The synapses are variously formed, depending on which part of the nervous system they belong to. Synaptic transmission is sometimes a chemical process, sometimes electrical, sometimes both. The principal chemical neurotransmitters are acetylcholine, noradrenaline, adrenaline and - in the CNS - dopamine and serotonin. Synapses can be inhibitory or excitatory.
Impulse transmission in the axons is strictly a one-way process. Differences in construction and transmission mechanism determine the various effects at the target organs.
We distinguish between stimulating or excitatory synapses and restraining or inhibitory synapses. Stimulation of the receptors is likewise effected by many different kinds of stimuli.
Thus, there are photoreceptors, chemoreceptors, thermoreceptors, pain receptors and mechanoreceptors, depending on whether they are activated by light, chemical or temperature stimuli, or mechanical influences such as stroking or jabbing, etc. Since more and more receptors are affected by a (continuing) stimulus, this makes possible a great variety of reactions. Depending on the kind of stimulus, the impulses in the CNS are either transmitted to higher centers (e. g. pain sensations) or processed in autonomic centers, which can then trigger involuntary reactions (e.g. reddening of the skin). This variety in the various component units accounts for the manifold impulse types. [2, 32]
1.1.2 Reflex Arc
A reflex is a response to a stimulus. Simply put, the stimulus is received by the axon via the receptor and passed on to the reflex center, where it is re-routed. Another axon then transmits a fresh impulse to the target organ. A reflex arc does not necessarily consist of just two neurons. Various neurons form a network of lateral interconnections. Because of this, a stimulus can end up at both an inhibitory as well as an excitatory synapse. A pain stimulus secondarily triggers swelling and reddening. The preceding gives just a hint of the complexity of reflex arcs. Reflexes can also be accompanied by emotional reactions, which once again illustrates the complexity of the excitation.
Reflexes are categorized into various reflex groups, such as fight-or-flight or affection reflexes. Manual Lymph Drainage triggers pleasure reflexes which give the patient a feeling of well-being. Basal muscular activity is reduced, which has a relaxing effect.
The activation of an inhibitory cell can dampen or even extinguish a parallel excitatory process. There are receptors that react to a stimulus for as long as the stimulus persists (pain stimulus), whereas others only react to a change in some aspect of the stimulus (mechanoreceptors). The varying pressure of Manual Lymph Drainage is first transmitted to the CNS as a touch sensation, but other (inhibitory) neurons are also activated via collateral connections. These can have a moderating effect on pain situations. Every stimulus should be regarded as a complex, which helps make the various possible reactions comprehensible.
The fact that nerve tracts get re-routed in the spinal cord explains why, in most indications, treatment of the opposite (contralateral) side is also effective.
See Fig. 2.
1.1.3 The Immune System
This is man's defensive system, which not only attacks infectious germs, but also foreign (non-self) substances, especially proteins. However, defensive mechanisms can also develop against inorganic materials. The human immune system distinguishes between [non-self] and [self] signals which are carried by protein bodies, polysaccharides and lipids. The human organism recognizes its own proteins, namely the ones present in the body at the time of birth. Under special pathological conditions, it can come about that the body identifies its own tissue as non-self and produces antibodies against it; this is known as an autoallergic disease.
The immune system works with two mechanisms: humoral immunity, for which certain proteins (gamma globulins) are responsible; and cellular immunity, which is carried out by certain cells (lymphocytes, plasma cells, macrophages).
1.1.3.1 Humoral Immunity
Antigens are the various foreign substances which can trigger an immune reaction. They react specifically with antibodies or sensitized lymphocytes. Antigens can be foreign protein bodies, polysaccharide-polypeptide complexes (e. g. the blood-type agglutinogens on the surfaces of erythrocytes), but also low-molecular-weight chemical compounds bound, for example, to albumin. Antibodies are present in all bodily fluids: blood, lymph, connective tissue. They are produced primarily in the lymph nodes. Chemically, they are globulins, divided into five major groups:
Fig. 2: Reflex arc schematic, with an inhibitory neuron in the circuit
Immunoglobulin A (IgA) - Used primarily to fight viruses, bacteria and altered forms of the body's own cells. It is formed from plasma cells and is