How to strengthen the immune system

Immune system is defined as a coherent group of cells, tissues, proteins, and organs that work side by side to defend the body against various microbes and bacteria from Bacteria, viruses, parasites, Parasites) which cause diseases. Immune system consists of three main types: innate immunity, the body's innate immunity from birth. External body barriers such as skin, mucous membranes of the throat and intestines, passive immunity, the immunity of the child From his mother through the placenta during pregnancy and breastfeeding after birth, and Acquired Immunity, an immunity that develops and changes through life with exposure to disease and germs, and thus this is the kind that can be strengthened.
The immune cells of the immune system are called lymphocytes. They are found in the primary lymph nodes, the bone marrow, which is responsible for their manufacture, and the thymus gland, where some of these cells mature and differentiate. In the lymphatic secondary organs are the lymph nodes, spleen, tonsils, and lymphatic tissues of the intestinal mucosa; the lymphatic organs represent the lymphocyte lymphocytes About the body.
Methods of strengthening the immune system
There are some tips that can be used to strengthen the immune system, as follows:
 Sleep: Sleeping for a sufficient number of hours helps to maintain the health of the body and the immune system, and estimated the number of hours of adequate sleep for adults seven to nine hours, Of the sleep raises the levels of stress hormone known as Cortisol (Cortisol), and that the rise of cortisol for a long time and repeatedly affect the effectiveness of the immune system, which may lead to inflammation.
Healthy food: Eat healthy foods, such as vegetables and fruits, because they contain essential nutrients such as vitamin C, vitamin E, beta-carotene, and zinc. It is important to note that eating large amounts of sugar reduces the efficiency of the immune system. 
 Sports: Moderate exercise such as walking regularly helps strengthen the immune system and helps to sleep well. 
 Mental Health: And constant pressure and tension for a long time raises the level of stress hormone, and makes people more susceptible to diseases; so you must learn how to deal with stress and control to maintain the immune system, and may help the following things to solve the problem of tension:
* Learn how to meditate; continuous meditation maintains a good immune response.
* Maintain strong social ties with others and stay away from unity.
* Sense of humor and laughter; laughter reduces the stress hormone and supports white blood cells that protect the body from diseases.
Sun exposure: The importance of sun exposure in stimulating the skin to produce vitamin D is important in maintaining the health of the respiratory system and reduce the risk of respiratory infection (Respiratory infections), and therefore advised exposure to the sun for 10-15 minutes in summer and without the use of sun protection  Vaccines: Vaccines are prepared using pathogens, whether weakened, dead, toxic, or a protein. The vaccine stimulates a series of immune system processes of identifying the UFO,
 Avoid Smoking: Smoking reduces the effectiveness of the immune system in protecting the body, especially the respiratory system. Smoking increases the chance of bronchitis and inflammation. Pneumonia, and middle ear infections in children. [4] Refrain from drinking alcohol: Drinking alcohol in the immune system negatively affects the risk of lung infections.