Our body is made up of thousands of billions of cells that make up tissues and organs, and the functions of the immune system support all. The body consists of about 200 different types of cells that occupy different functions. Cells of the same type come together to form tissues, such as the lining of the intestine or the surface of the skin. And different types of tissues come together to form an organ like the lung or the liver.
In creating man, God has endowed him with a defense system called the immune system.
In biology, immunity refers to the body’s ability to defend itself against threatening substances for its proper functioning or survival. These “threats” can be of 3 orders: microbes (viruses, bacteria, fungi, parasites), cells that have become cancerous, or a foreign body (a splinter, as well as a grafted organ).
It has long been known that with age or disease, immunity weakens, and the body becomes more vulnerable to infections. These last ones often become more frequent and more serious. The common flu can then degenerate into pneumonia and be fatal.
That said, we also note that some apparently healthy adults with a normal amount of immune cells (according to blood tests) often contract infections such as colds or gastroenteritis. On the contrary, under similar conditions, others are more resistant. The difference would be played out essentially in terms of lifestyle habits. Indeed, many data from epidemiological studies indicate that diet, smoking, sleep, physical activity, the degree of stress, the quality of human relations, and the living environment all influence the quality of the immune response.
Thus, health and immunity are closely linked: taking care of one’s day-to-day health improves one’s immunity and vice versa.
The Risk Factors section introduces lifestyle habits that weaken immune defenses, and the Prevention section, those that can reinforce them.
If at a given moment, the body needs an outside boost, various additional solutions can be used. The Medical Treatments and Complementary Approaches sections are the most commonly used.
Functions of the Immune System
1. What Is the Immune System?
The immune system defends the body against infections and diseases. Parts of the immune system look for unhealthy cells or substances that are foreign to the body, some send messages to other cells in the body about an attack, and others work to attack and destroy the microorganisms that attack the body. cause infections such as bacteria, viruses, fungi, and parasites, or unhealthy cells, such as cancer cells. When the immune system defends the body against infections and diseases, it is called an immune response.
2. Why Are the Functions of the Immune System Useful?
It is the functions of the immune system that provides punctual control against common infections, such as colds and flu, but also long battles against cancer. Having a healthy immune system is not only a guarantee of health but also of life! Without an immune system, a common scratch would become fatal as the scratch exposes our tissues to a host of naturally occurring microbes in the air, water, and skin.
Scientists are not very familiar with the characteristics of the “optimal” immune response. However, they know that the immune system is connected, through a complex communication system, with virtually every region of the body.
3. The Parts of the Immune System
The immune system is made up of cells and organs that work together to protect the body and respond to infections and diseases.
*** Lymphocytes
Lymphocytes are white blood cells found in the blood and lymphatic system. They attack viruses, bacteria, and other foreign invaders. There are different types of white blood cells, but lymphocytes play the most important role in the immune response. Lymphocytes are also called immune cells.
T cells, also called T cells, destroy damaged and infected cells in the body and tell B cells to make antibodies.
B cells, also called B cells, can be converted into plasma cells to make antibodies that help fight infections and diseases. B cells can also remember the types of infections and diseases that the body has already fought. If the same germ enters the body, B cells can quickly produce more antibodies to help fight it so you do not get sick.
Natural killer cells attack cancer cells or cells infected with a virus.
*** Antibodies
Antibodies, also called immunoglobulins, are proteins made by B cells that have been transformed into plasma cells. The antibodies circulate in the blood. They fight infections and defend the body against harmful foreign substances by recognizing a substance, such as a germ, that triggers an immune reaction and binds to it. The foreign substances or germs to which the antibodies bind are called antigens.
A specific antibody is made by the plasma cells to fight a specific antigen. The antibody binds to the antigen as a key enters a lock. So only the antibody made to fight against a specific antigen can bind to it, as a key that can open only a specific lock. When this happens, white blood cells are able to find and destroy the substance that causes infection or disease.
*** Bone Marrow
Bone marrow is the soft, spongy part of most bones and is where the blood cells are made. Many of the blood cells in the bone marrow are not fully developed (immature). They are called stem cells. Stem cells change and develop into different cell types, including blood cells. The majority of blood cells grow and mature in the bone marrow. Most blood cells leave the bone marrow and enter the circulating blood and other areas of the body, such as the lymph nodes and tonsils, once they are mature.
*** Lymphatic System
The lymphatic system is the set of tissues and organs that make and store cells that fight infections and diseases. The lymphatic system includes the tonsils, spleen, thymus, lymph nodes, lymphatics, and bone marrow.
*** Skin and Mucous Membranes
The skin and mucous membranes are the body’s first line of defense against infections and diseases. The skin prevents most germs from entering the body. But a cut or burn on the skin can allow germs to enter.
Germs can also enter the body through any opening, such as the mouth, nose, throat, anus, or vagina. The mucous membranes that line many parts of these openings help protect the body. Mucosal cells make liquids and substances that help kill germs. And in some areas of the body, the mucous membranes are acidic, which also helps prevent infections caused by bacteria and other microorganisms.
4. The Immune System and Cancer
Cancers of the immune system include lymphoma and leukemia, which are also types of blood cancer. But all types of cancer affect the immune system.
Since cancer cells come from our own cells, our immune system does not always know that it should attack them. Sometimes the immune system knows that cancer cells should not be there, but in general, they do not notice them. Cancer cells can even suppress the immune response, so immune cells do not attack them.
It is also often the case that the immune system of people with cancer is weakened. This is the case when cancer itself or its treatment, such as chemotherapy or radiotherapy, affects the bone marrow. Blood cells are made in the bone marrow and when it is affected by cancer or its treatment, the number of blood cells produced is lower than normal. When the number of blood cells is low, the body is not able to fight infections very well.
5. Cancer Treatments and the Immune System
Some medications can help the immune system to fight cancer. The treatment that uses these drugs is called immunotherapy. Immunotherapy strengthens the immune response or helps the immune system recognize and fight cancer.
Stem cell transplantation, also known as bone marrow transplant, is a substitute for immune cells, which are blood cells made in the bone marrow that fight infections and diseases. Stem cell transplants are mostly used to treat cancers that affect blood cells such as leukemia, lymphoma, and multiple myeloma. But stem cell transplants can sometimes treat other types of cancer such as testicular cancer, retinoblastoma, and neuroblastoma. The goal of stem cell transplantation is to ensure that the body is once again able to produce healthy blood cells, such as lymphocytes, which play an important role in our immunity.