The immune system is responsible for protecting and defending the body from microorganisms and other substances that can enter the body and cause diseases. It consists of a group of cells, tissues, organs and some other substances. The immune system can distinguish healthy cells from unhealthy cells. What is meant by unhealthy cells is either they are pathogenic and cause infection, or they are caused by cellular damage caused by non-pathogens such as sunburn or cancer. The immune system is characterized by its ability to distinguish a wide range of risk factors called molecular patterns associated with the occurrence of risk, in addition to distinguishing some signals that are released by microbes, called molecular patterns associated with the occurrence of disease, when the immune system receives these signals it responds immediately to diagnose the problem. 

Immune system localization

The immune system is a complex system that is widespread in all parts of the body, and it consists of a variety of cells that may move throughout the body, or may be located in a specific tissue. Each of these cells has a unique role and a different way of identifying a problem, communicating with other cells, and performing their function. But all immune cells originate in bone marrow and later develop into adult cells through a series of stages that occur in different parts of the body. The immune system is represented by the following:
  • The skin : The skin is the body's first line of defense against microbes, and it produces some anti-microbial protein substances, in addition to the presence of some immune cells in the layers of the skin . 
  • Bone marrow : Bone marrow contains stem cells that develop into many different cells. Where stem cells stem from the progenitor predecessor cells that later develop into innate immune (congenital) cells and are the first to respond to infections such as: neutrophil cells, eosinophils, basal cells, mast cells, dendritic cells and macrophages. While the form of stem cells with progenitor cells that lymphoid precursors develop into immune cells adaptive T cells Kkhalaaa B, which is responsible for the cells to respond to infection based on the precedent with the causes of these encounters any infection responsible for immune memory. In addition to the formation of natural killer cells from stem cells with lymph ancestor, the killer cells have common properties of innate and adaptive cells. 
  • Bloodstream : Immune cells spread into the bloodstream called white blood cells, and they run through the vessels throughout the body, and are constantly searching for any problems that may exist. 
  • Thymus gland : a small gland located in the upper part of the chest, in which the T cells mature. 
  • The lymphatic system : Immune cells are transported through the lymphatic system and accumulate in the lymph nodes. The lymphatic system consists of a group of cells and tissues such as lymph fluid, extracellular fluid and lymphoid organs such as lymph nodes that exist in all parts of the body.
  • Spleen : Although the spleen is not directly related to the lymphatic system, it is of great importance in processing information coming from the bloodstream, and certain places of the spleen are enriched with immune cells that activate and respond as soon as necessary. 
  • Mucous tissues: Mucous tissues are essential entry points for pathogens, so some immune cells are located in strategic locations in these tissues such as the respiratory tract and gut. 1

Immune cell functions

Among the most important immune cells in the body are white blood cells, which are called white cells, which are transported in blood or stored in certain tissues as we saw in the previous paragraph. And white cells are represented by two basic types that combine their efforts to search and destroy everything that might cause diseases in the body, whether microorganisms or extraneous substances. These two types are: 
  • Phagocytic cells (inspiration) : their function is to devour extraneous microorganisms, and there are many different cells that can be considered phagocytic cells, neutrophil neutrophil represents the  most common type in eliminating bacteria, and the number of these cells increases when any bacterial infection occurs, while other types of phagocytic cells Each has its own role to ensure an appropriate response to each type of invader. 
  • Lymphocytes: These are cells that give the body the ability to distinguish and remember former invaders, and help it destroy them. These cells form in the bone marrow, either they stay there and mature into B lymphocytes, or they move to the thymus and mature into T cells. These cells have different functions, so B cells can be likened to the body's military intelligence system, they search for their targets and send appropriate defenses to deal with them, while T cells can be likened to soldiers who destroy invaders according to orders issued by B cells. Then some T cells are called killer cells in every sense of the word, in addition to that they contribute to directing some other cells to do their work. 

How is immune memory formed?

When foreign substances, such as pathogens, enter the body, or can be called antigens, some immune cells identify them, and then respond to them by inducing B cells to produce antigens, which are protein substances that specialize in every type of antigen. But despite the production of antigens and their ability to distinguish and inhibit antigens, this will not be enough to eliminate them, and here comes the role of T cells to help and destroy the identified antigens. These antigens remain in the body, and recognize the antigens that you fought and fight again as soon as they enter the body again in the future. 

Immune system diseases

It is possible that the immune system weakens for many reasons, the weakness may be temporary and caused by many diseases such as influenza, infections and others, and some people may suffer from a weak immune system such as patients who receive chemotherapy, or have undergone bone marrow transplants, or who are taking some medications Inhibiting immunity, in addition to that pregnancy may weaken the mother's immune system, and in some cases the immune system may be the target of infection exactly as it happens when infected with HIV . As for permanent immune diseases, they are often genetic genetic disorders, caused by a change in the molecules responsible for the immune signal, or may result from the complete absence of mature immune cells.
Here are some diseases of the immune system:
  • Allergy : an overactive reaction due to the immense sensitivity of the immune system to certain substances that are not considered harmful, such as some types of food or pollen, and others. 
  • Autoimmune diseases : Autoimmune diseases happen when the immune system makes a mistake in determining the risk, and it attacks various tissues and organs of the body, resulting in many diseases. 
  • Sepsis : Sepsis or sepsis occurs when inflammation affects the bloodstream, which is a systemic inflammatory condition caused by the uncontrolled release and release of cytokines (protein substances), which activate immune cells throughout the body.
  • Cancer : Some forms of cancer may affect the immune system, when an uncontrolled division of the immune cells occurs, such as leukemia (leukemia) caused by the abnormal division of white blood cells. 

Support the immune system

Do you have an idea of ​​the number of microbes around you everywhere, and do you know how well they can cause diseases, but still most of the time are in good health, then thank your immune system and try to strengthen it and support it by following these steps:
  • Adequate sleep and reduced stress and stress : Increased feelings of stress and stress and not getting enough sleep increase the secretion of the hormone cortisol, which leads to the suppression of immune functions. 
  • Avoid smoking : smoking undermines the body's main defenses and increases the risk of bronchitis. 
  • Reducing drinking alcohol : Excessive drinking weakens the immune system and increases the risk of lung disease. 
  • Eat a balanced diet : that is, eat more vegetables, fruits, nuts and seeds, in addition to garlic, which is a broad-spectrum antimicrobial. 
  • Add probiotics to your diet . 
  • Sunlight : Get enough sunlight by walking for 10 minutes or a quarter of an hour daily, to get the necessary needs of Vitamin D, because Vitamin D deficiency may increase the risk of respiratory disease. 
  • Immune Supporting Herbs : Some types of immune support plants can be tried as Asian ginseng and others.