Total health is one of the main benefits of proper exercise training. To understand what total health means and how to go about working for it, some knowledge of human Physiology is necessary.
Physiology is the particular science concerned with the functions and activities of life or living things as well as the physical and chemical processes involved. Human physiology concerns itself with the various interrelated groups of organs that work together for one or more functions essential to human life.
There are many different ways to describe total health. It can simply be the absence of weakness and sickness, or the fitness to live a normal life. (A distinction between health-related fitness and performance-related fitness shall be discussed later on.) In relation to Physiology, one can say that total health is that state wherein all organs of the body function perfectly well under the control of a sound mind.
Being in the best of health supposedly retards physical aging. Physical aging is a physiological condition wherein changes in the body lead to senescence or the weakening of the systems and physical capabilities. It usually happens over time, as we grow old. Exercise training for health aims to slow-down or delay the onset of senescence.
The groupings of bodily organs according to function are called systems. We have 10 such systems; 1). the skeletal system, 2). the muscular system, 3). the skin, 4). the nervous system, 5). the circulatory system, 6). the digestive system, 7). the respiratory system, 8). the endocrine system, 9). the sense organs, and 10). the urinogenital system. You may hear about the lymphatic system and the immune system. Both are related to the circulatory system and the latter may be expanded to include every protective feature of all other systems.
The Skeletal System
The skeletal system involves the bones and joints. The primary function of bones is to provide rigid support to postures and movements. Some act as protective cover to vulnerable internal organs, like the skull that encase the brain and the bones of the rib cage that enclose the other organs. Teeth are bones that enable us to chew. Ossicles are tiny bones in the middle ear that vibrate with sound and allow us to hear. The joints allow us to bend, twist and change positions involving various body parts.
Each piece of bone in our body is living tissue. Within it is a natural factory for essential nutrients the body needs. It is the red marrow in bones that produces and supplies much of our blood cells. Bones, mainly made up of calcium, is also the storage of this all-important substance. Calcium is needed for normal heartbeat, the clotting of blood in wounds and muscular contraction. When blood calcium levels are low, the bones have to compensate.
The Muscular System
Muscles make up the muscular system. Skeletal muscles a.k.a. voluntary muscles are those that are attached to bones in such a way that, when they contract, we are able to move or do work. Some of these muscles also provide a protective cover for the internal organs.
Muscles in the intestines, the pupils of the eyes, other sense organs and internal organs are called smooth muscles. Those of the heart are called cardiac muscles. Smooth muscles and cardiac muscles are also called involuntary muscles because they do their work without us having to will them to.
The Skin
The skin is an organ. It has three main functions reflected in its varied appearance throughout the body. One is that the skin is our first line of defense against germs and impact. In this way it contributes to the overall immune system. Two is that it helps in controlling body heat through perspiration which, incidentally, also makes it an organ of excretion and detoxification. Three is that it is a sensory organ, making us feel touch, heat and cold. When exposed to sunlight, the skin also produces vitamin D naturally.
The hair and nails are parts of the skin. Both are made up of tightly packed keratin, the same dead cells that are continually shed off by the body.
The Nervous System
Including the brain as the central processor of information, the nervous system is composed of the spinal cord which basically runs down the spinal column of the skeleton and nerve networks that branch from it to other parts of the body. This system is made up of nerve cells called neurons. There are about 10 to 15 billion neurons in the brain alone.
We can simply consider the brain as the central processing unit, the inner computer that manages a complicated network of communication. We can think with our brain, of course, but the nervous system is primarily involved with gathering information from all parts of the body, for transmitting them to the brain for immediate processing, and for sending out orders from the brain to all systems and organs.
Nerves that gather information and send them to the brain are called sensory nerves or afferent nerves. Nerves that deliver messages or commands from the brain to all organs are called motor nerves or efferent nerves.
The brain and the spinal cord is also referred to as the central nervous system.
The nervous system has autonomic functions. These functions involve the control of involuntary muscles or commands that we need not be conscious of.
The Circulatory System
The heart, blood and blood vessels compose the circulatory system. The lymphatic system and immune system may also be involved.
Blood is liquid because of its main ingredient, plasma, which is 90% water. Being liquid the blood carries with it various substances that are either soluble or insoluble.
A basic component of blood are the red blood cells which contain hemoglobin. Hemoglobin increases the blood's ability to transport oxygen by about 50 times. Because of this, red blood cells are the primary carriers of the much-needed oxygen to every cell of the body.
From these same cells, the red blood cells also pick up the toxic by-product of metabolism called carbon dioxide and bring it to the lungs for expulsion.
White blood cells in the blood fight off infection and toxins. These cells assume various forms as appropriate to combat any foreign body perceived as "the enemy".
Platelets, also present in blood, allow clotting to stop wounds from bleeding. (There are other ingredients in blood which shall be discussed as we go along.)
The heart acts as a pump that enables used blood to flow from all parts of the body and fresh blood to replenish it. The blood vessels act as conduits.
Blood from the heart first goes through large arteries that leads to smaller arterioles which further leads to tiny capillaries in the tissues of organs. The exchange of used blood and fresh blood happens in the tissues.
Used blood is then absorbed by tiny capillaries that lead to venules which further lead to much larger veins and finally the heart. (The filtering system and other functions that make blood a supplier of nutrients to each and every cell in the body will be discussed later.)
Apart from the red marrow in bones, blood cells may also be formed and supplied by the liver, more so if there is an emergency demand like internal bleeding. Certain types of white blood cells may be formed at lymph nodes, at tissues in the intestines called Peyer's patches, and at the spleen. These types of white blood cells are called lymphocytes. They are at the forefront of fighting infection.
Normal blood cells are flexible yet firm. They are so flexible that, at the level of narrow capillaries, they can pass through one at a time.
From blood plasma, a pale liquid called lymph separates from the bloodstream to provide a wet environment and a way of cleansing for the cells in tissues. From the tissues, lymph travels back to the heart to join the bloodstream by another route. It travels through spaces between tissues, pumped forward by the squeezing action of moving flesh until it joins the bloodstream back to the heart via large veins near the neck. Thus is the path of the lymphatic system.
Lymph carries with it lymphocytes. If there is infection along its path, these lymphocytes block the spread of germs. This is the reason why we have painful lumps by the neck, armpit or groin. It is usually in these places that phagocytic cells, those that eat microbes and toxins, are formed.
Although what is known as the immune system has to do with our overall defense mechanisms against anything that can harm the body, the primary emphasis is on its role against infection. Thus it involves mainly the lymphocytes in the blood and lymph as well as macrophanges from the red marrow of bones. Macrophanges are phagocytic. If "the enemy" is big, macrophanges band together to form larger cells. Like lymphocytes, they reach the tissues through the circulation of lymph.
The Digestive System
The digestive system is composed of organs involved in the breakdown of food, the processing of nutrients into forms usable by the body and the separation of materials that are eventually disposed of as waste. This includes the mouth with teeth to chew and saliva which has digestive enzymes.
Principally involved are the intestines; the stomach, the small intestines and the large intestine. The liver, gallbladder and pancreas also play important roles.
The breakdown and digestion of food starts at the mouth. Food then is stored in the stomach which sends it in manageable amounts to the small intestines. It is in the small intestines where digestion is completed. It is also here that essential nutrients are absorbed and join the bloodstream. Excess water and waste matter goes to the large intestine until finally excreted through the anus.
It is in the first portion of the small intestines called the duodenum that digestion is completed. Bile produced by the liver and stored by the gallbladder is released to it so as to balance the acidity of food. Digestive enzymes from the pancreas are also mixed in. The bile and enzymes are necessary to completely digest the food so that nutrients may be absorbed through villi and into the bloodstream.
Villi are hairlike fibers that cover the inside of the intestines in a way that looks like a rolled carpet. From the villi, the nutrients picked up by the bloodstream are delivered to the various organs and cells that need them. There are more villi in the second portion of the small intestines, the jejunum. The third and last portion of the small intestines, the ileum, has the most villi.
The liver not only helps in the digestion of food, it is also responsible for the formulation of substances needed by the body. It forms amino acids which serve as the building blocks of new cells.
The liver also serves as the storage of glycogen. Glycogen is the source of glucose or blood sugar which fuel energy for physiological activities.
The pancreas produces the hormone insulin which is important in the utilization and control of blood sugar.
The Respiratory System
The lungs and the entire process of respiration concerns the respiratory system. From a simple perspective, it is the process of obtaining the much-needed oxygen from the air we breathe and the expulsion of the toxic by-product of metabolism called carbon dioxide.
Although the lungs are the major organs involved here, the circulatory system plays an indispensable role.
The air we normally breathe is about 78% nitrogen, 21% oxygen and 1% other gases. Of the 21% oxygen that enters our lungs, about 16% is immediately expelled out. This means that, for every inhalation, only 5% remains in the lungs. This enters small balloon-like compartments called alveoli where there are tiny capillaries to pick it up. Blood then carries oxygen, mainly through its red blood cells, to all other cells of the body.
Inside working cells, oxygen is used to break down nutrients so as to release energy. This action of oxygen is called oxidation, much like lighting a fire or an explosion. The reason we don't get burned is that enzymes slow down the process. The by-product of this metabolic process is carbon dioxide, a gas that is eventually expelled out of the lungs. A certain amount of carbon dioxide is needed by the body but in excess it is harmful.
The Endocrine System
The endocrine system concerns the endocrine glands which produce and release their respective secretions to the bloodstream. These secretions contain various hormones that influence the different chemical processes in our body. These chemical processes have to do with growth, metabolism and reproduction.
We shall discuss each of the glands in greater detail later. For now, let it suffice to note of a pituitary gland and a pineal gland situated at the brain area, adrenal glands at the kidneys, the islets of Langerhans at the pancreas, a thyroid gland by the throat, the parathyroid glands below the thyroid gland, the gonads (testicles or ovaries), and the thymus at the chest area.
The Sense Organs
The sense organs are a system of their own although we can say that it is the nervous system with its nerves that make us sense. We have the eyes for vision, the ears for hearing, the nose for smelling, the tongue for taste and the skin for touch. In all other parts of the body, we can feel because of sensory nerves.
The Urinogenital System
The urinogenital system involves the kidneys and the path of urine. This also involves the sex organs. It is the function of this system to maintain the cleanliness of blood as well as to rid it of substances that can cause clogging in the systems.
Kidneys serve as the filters or purifiers of liquids in our body, the blood in particular. Aside from this function, the kidneys also serve to salvage substances that may still be needed by the body and exclude for eventual disposal wastes that then goes out with urine.
It is estimated that about 42 gallons of liquid or blood passes through the kidneys daily for filtering.
We can go on and on researching much of human physiology. It is enjoyable as well as useful. However, in relation to this presentation, we have enough to work with.
The normal and effective functioning of any and all systems of the body depend on the normal and effective functioning of the organs involved. The normal and effective functioning of any organ depends on the normal and effective functioning of its tissues. Then, the normal and effective functioning of any tissue depends on the normal and effective functioning of the cells in it. We can add that the normal and effective functioning of cells also depend on the normal and effective functioning of the connective tissues that bind them together.
It is among the cells, in the cells, and connective tissues that the deterioration of health and physical aging have their roots. The crusade against diseases and senescence, efforts to achieve total fitness and delay physical aging, should start here. Cells are primarily damaged by oxidative stress. Less stressful physical exercises and the use of natural antioxidant supplementation can be helpful.
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