The COVID-19 epidemic continues to 'make things happen'. The whole people know that wearing masks can prevent the virus from attacking. However, to maintain a healthy body function for a long time, we still need to pay attention to strengthening our physique and improving our resistance. The 'strong constitution' and 'resistance' mentioned here are actually a manifestation of human immunity.

　　The so-called immunity is a kind of defense mechanism of the human body itself, which is used to identify and eliminate 'dissidents'. Our 'immune system' performs this function in the human body.

　　The immunity of the body is divided into two types. One is a series of defense functions gradually established in the long-term development and evolution process, namely 'non-specific immunity', also known as innate immunity; The other is called 'specific immunity', also known as acquired immunity, which is the ability of human body to resist infection through acquired infection (recovery or asymptomatic infection) or artificial vaccination (such as vaccine, immunoglobulin, etc.).

　　The human immune system is a very complex 'project', which is mainly composed of immune organs, immune cells and immune active substances.

　　The local immunity of the respiratory system has its own characteristics. The respiratory tract is an open organ, which can breathe day and night. It can inhale various pathogenic microorganisms, allergens and dust in the air. The first thing to protect it is the peripheral barrier, for example, the coarse particles (>10 μ m) will be blocked in the nasal vestibule by the nasal hair. Smaller particles will enter the respiratory tract. At this time, a series of non-specific defense mechanisms of the respiratory tract will play a role:

　　1、Mucosa and cilia of respiratory tract

　　The complete mucosa of the respiratory tract can block the invasion of microorganisms. The normal movement and fluctuation of the bronchial mucosa ciliary system can continuously discharge foreign bodies at a frequency of 1200 times per minute to keep the bronchus sterile. In patients with bronchitis and bronchiectasis, the number of bronchial cilia decreases, and due to excessive secretion of mucus, the function of cilia becomes invalid.

　　2、respiratory secretions

　　The secretion of respiratory tract mainly contains acid and neutral polysaccharide, which can inactivate some viruses. There are mucus, albumin, immunoglobulin (Ig), etc. in the secretion of trachea and bronchus, which can nonspecific prevent the invasion of bacteria and viruses.

　　3、lymphocyte

　　When lymphocytes are stimulated by antigen (Ag), they can generate specific immune response. Lymphocytes are divided into T cells and B cells. T cells mature in thymus and B cells mature in bone marrow. It was found that most of the lymphocytes in bronchoalveolar fluid were T lymphocytes.

　　4、macrophage

　　The clearance of particles entering the alveoli mainly depends on alveolar macrophages. After the alveolar macrophages engulf foreign bodies, they can be decomposed and cleared by lysosomal enzymes. Macrophages that engulf foreign bodies are coughed up from the alveolar cavity through respiratory mucus flow and ciliary movement. Some mediators released by macrophages can also play a role in regulating and enhancing defense. Therefore, the integrity of their functions determines the occurrence, development and prognosis of many respiratory diseases.

　　Macrophages must also play a role in the specific defense mechanism. Macrophages engulf and process antigens, and then transmit antigen information to T cells to cause specific immune response. Lymphatic factors produced by T cells can attract and activate macrophages, but the enhanced bactericidal ability of activated macrophages is nonspecific.

　　It can be seen that respiratory diseases are closely related to the immune function of the respiratory system. Improving the respiratory immune capacity is an important means to prevent and combat respiratory diseases. So, in addition to paying attention to diet and exercise, what other ways can we improve the immune function of the respiratory system in our daily life?

　　Sinashu Salsol therapeutic apparatus It adopts pure natural, non drug 'salt therapy', combined with modern scientific and technological means, to prevent, improve and treat respiratory diseases and enhance the immune function of the respiratory system. The dry salt aerosol released by the Sinashu Salsol Therapeutic Apparatus is almost involved in all aspects of non-specific immunity of the respiratory system：

　　The particle size of dry salt aerosol is 1-5 microns, which can enter the human respiratory tract mucosa cilia and bronchoalveolar. By supplementing the ionic components of the respiratory tract mucosa, the osmotic pressure gradient can be increased, thereby humidifying the airway, diluting the excessive mucus secreted due to pathological changes, restoring the swing vitality of cilia, and promoting the excretion of sputum。

　　The main component of dry salt aerosol, sodium chloride, has a natural bactericidal effect, which can kill pathogenic microorganisms entering the mucous membrane and help maintain the sterility of the bronchus.

　　Dry salt aerosol also plays a regulatory role in the immune process of human lymphoid T cells. A study conducted by Fujian Medical University and Fuzhou Lung Hospital showed that inhalation of rock salt aerosol can lower the level of IL-4 in serum and increase IFN- γ (gamma interferon) level, changing IFN- γ /  IL-4 ratio, so as to correct the imbalance of Th1/Th2 cells in the body, adjust the abnormal immune status of asthma patients, and improve clinical symptoms.

　　In the immunity of the respiratory system, pulmonary macrophages can be called 'scavengers' of the respiratory tract. Maintaining the activity of pulmonary macrophages plays a vital role in the normal functioning of the immune function of the entire respiratory system.

　　Recent studies have shown that macrophages express a variety of proteins that control the ingress and egress of ions (i.e. ion channels), which play an important role in the life activities of macrophages. The sodium channels involved in the regulation of macrophage phagocytosis can activate its innate immune antiviral signal pathway. The supplement of dry salt aerosol can help maintain the normal expression of bioelectrical signals of sodium ion channels on macrophages and promote their effective regulation of the immune system.