Neurotransmitters
An essential part of the working of the nervous system is a group of chemicals known as neurotransmitters. There are excitatory and inhibitory neurotransmitters in the parasympathetic and sympathetic nervous systems. Excitatory transmitters stimulate action; inhibitory neurotransmitters inhibit it. When an impulse passes down a parasympathetic nerve, acetylcholine appears at nerve endings and then it transmits the effects of the parasympathetic impulse. This system is involved in maintaining normal levels of activity. The same happens with the sympathetic nervous system, which works in conjunction with the former. At the nerve endings the chemical noradrenaline (a hormone closely related to adrenaline) is released as a neurotransmitter by sympathetic nerve endings. Among its many actions are constriction of swollen blood vessels, often leading to an increase in blood pressure. Increasing the blood flow through the coronary arteries and slowing of the heart rate increases the rate and depth of breathing and complete relaxation to the smooth muscle of the intestinal walls.
Even today there is still a lot to learn about their different types and what each individual chemical does. Most nervous disorders are linked to the homeostatic imbalance of these substances. Many of the 50 or so neurotransmitters of the nervous system are thought to be neuromodulators; the largest group is known as the neuropeptides, which are thought to include both excitatory and inhibitory factors. One particular neuropeptide found within the sensory nerves, the spinal cord pathways and certain portions of the brain is known as substance P; it is thought to stimulate the perception of pain. It is also thought to be involved in the spinal cord pathways and certain portions of the brain that are associated in pain transmission. Conversely, it is known that substances called encephalins have their powerful analgesic effects on the body by inhibiting pain impulses; the endorphins also possess strong analgesic and behavioural effects. The analgesic compounds are concentrated in the thalamus, the hypothalamus and the pituitary gland. This correlates with what Fitzgerald said in those early years, that stimulation to the pituitary gland reflex point is thought to block or suppress pain. He also elaborated: ‘these functions were carried out by the pituitary body and multiple nerve pathways from it’. It may be that stimulation of the pituitary reflex causes the pituitary body to release adrenocorticotrophic hormone (ACTH), which is released in response to stress, and which controls the release of corticosteroid hormone from the adrenal cortex, a powerful anti-inflammatory substance that helps many of the disorders of the body.
Reflexes
Another function of the autonomic nervous system is that of reflex nervous action. A reflex is an automatic involuntary activity brought about by a relatively simple nervous circuit without conscious control being involved. Thus a painful stimuli will bring about a reflex of withdrawing even before the brain has had time to send a message to the muscle involved. This is a reflex action that has been conditioned by other considerations, it is a protective reflex.
Reflex actions are extremely important. They adjust the tone of muscles, particularly those used in posture. It is for this reason I think reflexology has such a dynamical effect on all the spinal nerves of the vertebrae, improving all back and neck related problems.
The medical profession use reflexes for diagnosing many disorders of the nervous system. The most used one, often referred to in reflexology, is the Babinski reflex sign or plantar reflex; this is brought about by drawing a blunt instrument or stroking the lateral side of the plantar area of the foot from the heel to the little toe. In any person over the age of 18 months old, the normal flexor response would be a downward bunching of all the toes. When there is a reverse upward action of the great toe this is indicative that there may be some evidence of a disorder in the brain or spinal cord.
The hypothesis of reflexology is that the medical fraternity expect a reflex on the foot to indicate some clinical significance enabling them to assess a condition in the body (i.e. they are ‘reading’ the message coming out); a reflexologist uses the same sensory pathway of stimulation to send a message into the peripheral nervous system, which is a two-way circuit, and on into the central nervous system, a vast nerve network, and through the many interconnections here to reach the autonomic visceral reflexes of the sympathetic and the parasympathetic nervous systems that adjust the activity of the organs of the body cavities in the torso.
As reflexologists we work on the feet, dealing mostly with the minute reflexes. The nerve pathways are thought to traverse through the feet and body. Because of this, often when working on patients they feel a shock or stimuli on the opposite side of the body. This is considered to be crossed reflexes. The term ‘crossed reflex’ is often used in zone therapy and reflexology. The original neurological term refers to a response that is brought forth on the opposite side of the body to that on which the stimulus was administered, from ascending nerve tracts entering the opposite side of the brain. The term ‘crossed reflex’ in reflexology indicates an area of referral. This connection affects not only the corresponding organ that has an anatomical connection but also the represented area of the body; for instance, in the case of the head area, we know that if we stub our toe a headache may often develop. Cross reflexes can be used when it is unsuitable to work on a corresponding area, especially if there is any injury or damaged skin; for instance, if the patient has a broken toe, you could get an equal relief of pain by working on the thumb, so the injured part can be avoided. These reflexes can also be used as an area of assistance if the corresponding area is too tender. An area of assistance or helper area is another part of the body that may support or relieve the organ that is injured or has an imbalance through its anatomical connections.
Fitzgerald spoke of the following anatomical correspondences (figure 2.7)
• arms and legs correspond
• palms and soles correspond
• dorsal hands and dorsal feet correspond
• fingers and toes correspond
• wrists and ankles correspond
• hips and shoulders correspond.
This anatomical connection has always been part of TCM.
We know these reflexes are highly complicated and are still not fully understood. As therapists we need to have a knowledge of all these systems of the body thus enabling us to have a greater understanding of how reflexology works. For instance, why is the relaxation on the solar plexus area done on both feet? It was traditionally explained that it was concluded together so as not to cause an imbalance, even though we have only one solar plexus. When we rotate the pressure on the solar plexus point it can be explained in two ways: stimuli to the foot between zones 2 and 3 has a direct connection to the coeliac plexus because we are also rotating on the same area on the right foot. This area on the feet and hands is important when treating depression. The reason for solar plexus relaxation must be that both feet benefit from this dual stimulation. We know that the solar plexus is a strong network of sympathetic nerves and ganglia located high at the back of the abdomen. On the feet and hands the corresponding area lies between zones 2 and 3, just below the diaphragm line. This same area on the feet is the first point of the Kidney meridian (KI-1) according to TCM; it is an essential point for all acute problems, and it is a very effective point for all cases of any urgency. The corresponding point on the hands is PE-8; this is also a very potent effective point and is very dynamic in clearing excess heat from the heart and it has a wonderful calming effect on the mind. The Pericardium meridian originates from the chest area and descends through the diaphragm to the abdomen, another branch shoots off to the nipple and then to the axillary area to descend down the arm to terminate in the large finger (see figure 2.10); this channel is often considered to be connected to the emotions of elation and contentment.
Figure