“The God of Israel is he that giveth strength and power unto his people. Blessed be God.” Psalm 68:35.
God has given us strength in many ways: physical strength to lift heavy loads or walk a long distance; mental strength to solve difficult problems; emotional strength to handle stressful moments; and spiritual strength to withstand temptations. He has also designed our bodies with a wondrous immune system—the lymphatic system—that provides strength against invading germs. Without a working immune system, each one of us would die soon after birth. Germs are everywhere, and although many of them are friendly to man, the microbes that are not would conquer us quickly.
Last month we discussed the cardiovascular system. The lymphatic system works in tandem with the cardiovascular system, and the systems have a lot in common. Like the cardiovascular system, the lymphatic system has vessels. Larger lymph vessels are very similar to veins, complete with valves, and the tiny ones are called capillaries. Lymph fluid does not use a pump like the heart but uses the contraction of skeletal muscles to move the fluid through the lymph vessels.
The lymphatic system actually has three major functions: absorption of excess fluid and its return to the bloodstream; absorption of fat; and the function of the immune system. Besides the vessels, the lymphatic system consists of lymph nodes and organs such as the bone marrow, spleen, and thymus. Certain cells called lymphocytes, monocytes, and leukocytes are produced in bone marrow. Lymph nodes are areas of concentrated lymphocytes along the lymphatic veins. The spleen is like a large lymph node except that it is also filled with blood. The spleen filters and purifies the blood and lymph fluid that flow through it. The thymus secretes a hormone that causes certain immune cells to mature.
The capacity to repel and destroy foreign substances and cells is called immunity. Your skin is the body’s first line of defense, providing a barrier to microbes and toxins. If this barrier is breached, or if foreign substances bypass it, then more specific immune defenses must be deployed.
Someone once said, “A family is a unit composed not only of children but of men, women, an occasional animal, and the common cold.” When we get an illness, such as a cold or the flu, we develop symptoms. The market is full of over-the-counter medications designed to reduce or mask these symptoms. Such medication may make you feel better temporarily, but will not cure. The reason is because the symptoms are not the problem. They are only evidence of the existence of a problem; they are the body’s efforts to kill the bug. (See The Ministry of Healing, 127.)
Fever, for example, is not an illness in itself but a symptom. Damaged cells release chemical signals that increase the blood flow to the area. When a scratch or cut becomes red, swollen, and warm, for example, the warmth makes an unpleasant environment in which germs are less likely to survive. The warmth also increases the mobility of immune cells. The body raises its temperature in order to kill the bug. It is said that for every degree the temperature rises, white blood cells (powerful immune cells) race to the site of infection twice as fast.
A runny nose and cough are the body’s way of shedding invading microbes from the nose and lungs, respectively. It is better to support the body in its fight back to health than to simply mask the symptoms.
Often the inflammatory process is enough to halt the invasion. Sometimes, however, microbes continue to survive. If this occurs, the body sends in its next line of defense. Certain proteins, called complement proteins, are made in the liver and form a membrane-attack complex (MAC) that embeds itself into the “skin” of the invading microbe. The complex makes a hole in the microbe and fluid rushes in. The microbe swells and finally bursts, dying instantly. Another defense occurs via production of antibodies. Each microbe invader has antigens on their surface. Antibodies bind to the antigens in a lock-and-key method, killing or inactivating the microbe.
The lymphocytes that are formed in the bone marrow migrate to the thymus and become T cells, very important immune soldiers. Another type, B cells, also mature in the bone marrow and produce antibodies. Macrophages are a type of white blood cells that is continually in search of foreign invaders. They are like police cruisers patrolling the city. When the macrophage finds an invader, it does not cart it off to jail. It eats it!
If the immune system over-reacts, people develop allergies or autoimmune diseases. If it under-reacts, disease and death may result. Allergies are caused by a hypersensitivity to weak antigens that the immune system ignores in most people. When some people are exposed to an allergen (like grass) the first time, their bodies make antibodies against it. The next time the person mows the lawn, they develop a much larger immune response, releasing histamine, which starts the inflammatory process. This response can range from mildly annoying all the way to life threatening.
Normally, the immune system is able to distinguish “me” from “not-me.” That is why it attacks invading microbes and not the body’s own cells. Occasionally, the immune system attacks and destroys cells of the body. Examples of these autoimmune diseases include multiple sclerosis, lupus, and rheumatoid arthritis.
We must make every effort to keep our immune systems healthy and well-able to defend us from the germs all around us. Ellen White warns us also of spiritual germs that we must have strength to fight against: “Satan has wrought with deceiving power, bringing in a multiplicity of errors that obscure the truth. Error cannot stand alone, and would soon become extinct if it did not fasten itself like a parasite upon the tree of truth. Error draws its life from the truth of God. The traditions of men, like floating germs, attach themselves to the truth of God, and men regard them as a part of the truth. Through false doctrines, Satan gains a foothold, and captivates the minds of men, causing them to hold theories that have no foundation in truth.” Review and Herald, October 22, 1895.
“Unto thee, O my strength, will I sing: for God is my defense, and the God of my mercy.” Psalm 59:17
Sheryle Beaudry, a certified teletriage nurse, writes from Estacada, Oregon where she lives with her husband and twin daughters.