Some terms that you may not be familiar with that may be used on this site are explained briefly below.
The cell
The human body is made of 100 trillion specialised cells all working as a community and all intercommunicating. Although all cells have different structures and functions they all share some basic features as shown here.
All cells are encased in a cell membrane and contain little organs known as organelles in the liquid gel cytoplasm or cytosol that surrounds the nucleus.
The Nucleus
Nearly all cells carry the genetic information for the whole in the form of DNA in the nucleus of the cell, although different parts are expressed in different tissues by processes that are not understood so that the cells of the eye are different to the cells of the liver, for example.
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The mitochondria
These organelles are known as the ‘power stations’ of the cell and actually account for 70% of the cell! It is here that the fuel that powers the body is synthesised from glucose derived from food. The glucose sugar ring is split in the presence of oxygen into Adenosine Tri Phosphate (ATP) by a process known as Kreb’s cycle or the citric acid cycle. The ATP then passes into the body of the cell where it used to fuel all cell functions by breaking a high energy phosphate bond and thus producing Adenosine DiPhosphate or ADP which then returns to the mitochondria to be recycled.
Receptors
The cell membrane is composed of phospholipids which means that it contains a large proportion of fat. Within this membrane are embedded receptors and this is also true of the organelle membranes. Circulating molecules (known as ligands) dock with their respective receptors and their 3D shape is critical to this process. In this way, hormones synthesised in one organ are transported in the blood stream to dock with receptors in a remote target tissue.
Once a ligand docks with its receptor, substances are either permitted entry to the cell or some process is set in motion within the cell. The real intelligence of the cell is now thought to reside within these membranes rather than being a function of the nucleus as previously thought.
Digestion
The organs of digestion are found primarily in the abdomen and, according to the naturopathic model, nearly all health problems are thought to start with a compromised digestion. Digestion takes place inside a tube that runs through the body (a bit like the hole in the doughnut), but the foods technically remain outside the tissues proper. This tube is variously referred to as the gut, intestine, gastrointestinal tract or alimentary canal. Foods are propelled along this tube and mixed with various enzymes which break them down into small molecules that can then be absorbed and used by the body for repair and other body processes.
The organs involved in digestion and their functions are outlined below.
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The mouth
Food is chewed and mixed with saliva which starts the digestion of starches.
The stomach
Food is churned in the stomach and mixed with stomach acid and pepsin which starts to break down proteins.
The small intestine
Immediately on leaving the stomach the contents are met by bile from the gall bladder which emulsifies fats and alkaline pancreatic juices from the pancreas which contain mixed digestive enzymes. The walls of the small intestine secrete further digestive enzymes and these complete the processes of digestion. Nutrients are mostly absorbed in the latter parts of the small intestine.
The large intestine
The liquid paste passes from the small intestine into the large intestine through a sphincter (ring of muscle) and it is here that the contents are churned in pouches and water is absorbed to produce the solid waste, faeces. The large intestine also contains vast numbers of bacteria which break down any remaining foodstuffs and produce some vitamins which are absorbed and used by the body.
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The liver
All nutrients and/or toxins absorbed from the intestines are transported directly to the liver in the portal vein where the blood is filtered. The liver has over 500 functions and one of the most important is the detoxification of substances. All substances are processed first through a process known as hydroxylation (Phase I detoxification) whereby substances are made water soluble.
Some of these substances can be excreted in the urine in this state but the majority are further processed by conjugation (Phase II detoxification) whereby various substances are added on and are then excreted in the bile.
The end result of phase 1 detoxification can result in the temporary creation of substances that are more toxic than the original substance but with the ultimate aim of further processing them to become less toxic.
The demand for nutrients in both phases is quite high and many people may have an inherited defect in one or more of these processes which also makes them vulnerable to toxin build-up.
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The gall bladder
This acts as a short-term storage organ for bile which is being produced by the liver all the time. It contracts when fatty foods are eaten squirting its contents into intestines and giving the faeces their brown colour.
The pancreas
The pancreas is a dual-purpose organ which produces digestive enzymes which empty into the small intestine in addition to having an endocrine role in controlling blood sugar.
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The endocrine system
The prefix ‘endo’ means ‘within’ and here it is used to refer to a system of widely separated intercommunicating and interdependent glands within the body that release hormones directly into the circulation. These circulating hormones act as messengers that find their way to a specific target tissue receptor and cause some sort of effect.
The endocrine system consists of the following organs:
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The testes in men and the ovaries in women which produce sex hormones
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The thyroid gland in the neck which controls metabolism
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The parathyroid glands embedded in the back of the thyroid gland which regulate mineral balance
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The thymus (behind the sternum – not shown) which plays a key role in the immune response
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The pancreas in the upper abdomen which regulates blood sugar
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The adrenal glands which are positioned on top of the kidneys and are primarily responsible for the response to stress but also have other functions
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In addition to the three controlling glands in the brain:
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The pineal gland or ‘third eye’
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The hypothalamus (pronounced hi-po-thal-a-muss) which is a cluster of nerve sensors in the base of the brain that monitors hormone levels
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The pituitary gland which acts as a store of stimulating hormones and is intimately connected to the pituitary gland
Click this link to find out more about the Endocrine Gland Disorders that commonly affect fatigue sufferers.
The immune and lymphatic systems
The immune and lymphatic systems are closely connected and are often regarded as different parts of the same system.
The lymphatic system
The lymphatic system is a one-way system that runs in tandem with the circulatory system and transports fluids from the tissues to the veins near the heart. It drains excess fluid away from the tissues and also filters the lymph produced through a series of lymph nodes which police the contents and activate an immune response if anything untoward is detected.
The lymphatic system has no pump - unlike the circulatory system and relies upon pulsing in the walls of the larger vessels and movement of adjacent structures to promote circulation. The tonsils, adenoids and Peyer’s patches of the intestines are examples of superficial lymphatic tissue.
The immune system
This is an immensely complex, sophisticated and delicate system of responding to perceived threats, which can include bacteria or foreign proteins from a substance such as an egg - in which case the response would be regarded as an allergy.
There are two arms to the system of immune cells which all originally develop in the bone marrow. One type of cell is processed in the thymus and for this reason is referred to as a T-cell and the other is further processed in the bone and is known as a B-cell.
These two systems interact to aid one another in initiating and terminating an immune response and keeping a ‘library’ of previous proteins encountered for future ready reference.
The nervous system
For convenience, the nervous system is regarded as being composed of the central and peripheral nervous systems. The central nervous system includes the brain and spinal cord, and the peripheral nervous system is the system of nerves that connect it to distant body parts.
These peripheral nerves can be either sensory or motor nerves. Sensory nerves convey information to the central nervous system concerning the outside world (via the special senses such as sight and hearing) and from within the body (such as pain or joint positions).
Motor nerves relay instructions back from the central nervous system to the tissues and these usually cause the body to respond in some way.
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The brain
The brain constantly monitors and processes millions of pieces of information from the sensory nervous system and makes adjustments via the motor system. The brain is mostly water and of the remainder the majority is fat.
It is protected by the skull and various membranes and suspended in a watery fluid known as cerebrospinal fluid. The fatty membrane and its associated cells present a selective barrier to some substances known as the blood/brain barrier.
The body will always try and maintain the function of the brain at the expense of other tissues or organs.
The Triune brain
The brain is arranged in three layers with the so-called reptilian brain responsible for self-preservation and aggression innermost, enclosed by the limbic system or emotional brain and outermost conscious cerebellum or thinking brain.
The limbic system incorporates several structures at the base of the brain including the amygdala which is a small cluster of nerve cell nuclei involved in emotion and memory and the hypothalamus.
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Neurones
Neurones are the building blocks of the nervous system and are long single cells that have an expanded cell body with a number of processes known as dendrites (normally in the central nervous system or a ganglion – a neurone ‘junction box’) and a long process known as an axon which is often insulated by a substance known as myelin.
These axons are bundled together to form nerves. Information is generated chemically in response to some stimulus within the terminal branches and passes along the axon electrically to the cell body. Transmission between neurones is chemical using neurotransmitters.
The autonomic nervous system
The autonomic nervous system (A.N.S.) is a critical arm of the motor system which controls all the automatic functions that occur beneath conscious awareness such as digestion, breathing, urination and sweating.
The autonomic nervous system is composed of two opposing systems, the parasympathetic (P.S.N.S.) and sympathetic nervous systems (S.N.S.). These work respectively like the brakes (P.S.N.S.) and the accelerator (S.N.S.) in a car.
There are so many branches of the A.N.S. involved in digestion that this network is often referred to as the ‘second brain’ and the ANS is also responsible for sexual sensation and arousal.
The parasympathetic supply comes from either from nerves that originate in the skull (cranial nerves) or from the sacrum (pelvis) and the sympathetic supply mostly from the thoracic nerves (chest) which then form a series of ganglia either adjacent to the spine or the organs they supply.
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The Reticular Activating System
One small part of the brain which is located where the spinal cord and brain meet is known as the Reticular Activating System and has been implicated in C.F.S., fibromyalgia and other disorders such as Alzheimer’s disease.
It contains 70% of the brain’s nerve cells and acts as a filter between conscious and unconscious awareness. It is associated with motivation; arousal; regulating the sleep-wake cycles; consciousness; muscle tone - especially of core supporting muscles; heart rate; breathing and modulating pain.
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Further resources
Please refer to chapters 4 and 5 of Chronic Fatigue, M.E., and Fibromyalgia: The Natural Recovery Plan for an in-depth explanation of how mercury adversely affects all body systems.
"Alison's journey to good health should be an inspiration to all. En route she has to oust what must be one of the most complex and least understood diseases of the 21st century."
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