Lymph node is the unique organ of mammals. Normal human’s superficial lymph nodes is very small, smooth, soft, no adhesion with surrounding tissue and no tenderness, less than 0.5 cm in diameter . When the bacteria enter into your body from the site of injury, the lymphocytes will produce lymphokines and antibodies to kill the bacteria effectively. The result is lymphocytes hyperplasia and histiocytosis of the cellular response to lymph nodes within the lymph node, as lymph node reactive hyperplasia. viruses, certain chemicals, toxic products of metabolism, degeneration of tissue components and foreign matter Can cause lymph node reactive hyperplasia . Therefore, the enlarged lymph nodes are the body’s beacon, a warning device
Tonsil is the largest lymphoid tissue in pharyngeal. In childhood, it is an active immune organ, containing all developmental stages of the cell, such as T cells, B cells, phagocytic cells. It therefore has a role in humor immunity, resulting in a variety of immune globulin, also have some role in cellular immunity. Tonsil IgA immunoglobulin produced a strong immune system, inhibit bacterial adhesion to respiratory mucosa, and inhibit bacterial growth and spread of the virus has neutralization and inhibition.
Human hematopoietic bone marrow is located within the body’s bones. There are two types of adult bone marrow: red marrow and yellow marrow. Red bone-marrow manufactures red blood cells, platelets and various leukocytes. Platelets have hemostatic function, white blood cells can kill and suppress a variety of pathogens, including bacteria, viruses, etc.; some of the lymphocytes produce antibodies. Therefore, the bone marrow is not only the blood-forming organs, but also an important immune organ.
Spleen is the body’s largest lymphoid organ, located in the left upper abdomen. The main function of the spleen is filtering and storage of blood. Spleen is a crisp texture and a rich blood supply of organs. It is easy to break in the event of a strong external force to combat. Splenic rupture can cause serious bleeding. It is one of acute abdomen to death.
Thymus (thymus) as an important body in lymphoid organs a ductless glandular organ at the base of the neck that produces lymphocytes and aids in producing immunity; atrophies with age which is closely associated with immune function. Which locate in the chest before the mediastinum during the late embryonic stage and birth, the human thymus weighing about 10 to 15 grams. With age, the thymus continues to develop, to the adolescent about 30 ~ 40 grams. After puberty, the thymus shrinks to only 15 grams aged thymus.
Immune globulin is a protein with antibody activity in animals. Mainly in plasma, also found in other body fluids, tissue, and some secretion of fluid. Most of immunoglobulin Human plasma present in the gamma globulin. Immune globulin can be divided into five types IgG, IgA, IgM, IgD, IgE .
Human respiratory system is the main gateway connected with the outside world. pathogenic microorganisms and harmful substances can often lead to inflammatory diseases which enter into the respiratory tract with the air . there were lymphoid tissue locate in the entire respiratory tract from the nasopharynx to the respiratory bronchioles and alveoli, typical of the lymph nodes are in the surrounding of trachea and bronchi.
In recent years, with the development of immunology people pay more attention to the relationship between immune and digestive tract diseases increasingly. Digestive tract of non-specific immunity include: full digestive tract from mouth to rectum mucosal barrier, all decomposition enzymes, bile, liver barrier, gastrointestinal peristalsis and natural flora.
Mucosal immune system is relatively independent of the systemic immune system, it had also inextricably linked with the systemic immune system. Mucosal immunity constitutes the two major functional areas: the immune induction site and parts of immune responses. Lymphocytes in the body immune system and mucosal immune system move continuously between the two major functional areas, accompanied by cell differentiation and maturation of their own.