Being strong and staying strong in the immune system is essential to maintaining good health. Without a strong immune system, the body will not be ready to attack bacteria, viruses, parasites and more. This immune system keeps the body healthy against pathogens.
The structure of the immune system is a vast network of cells and tissues that are constantly monitoring the body and preparing a complex attack upon seeing the enemy.
The immune system spreads throughout the body and involves various types of cells, organs, proteins, and tissues.The important thing is that it can distinguish the internal tissue from the external tissue. Dead and defective cells are also recognized and cleared by the immune system.
If the immune system encounters a bacterium, virus or parasite such as a pathogen, the so-called immune response is given.Here’s how the immune system works, but first we’ll introduce some of the key characters in the immune system.
White blood cells
White blood cells or leukocytes circulate in the blood vessels and lymph vessels that are parallel to the veins and arteries.
White blood cells are constantly on the move looking for pathogens. When they find a target, they start replicating and sending signals to other cells to do the same.
White blood cells are stored in different places in the body called lymphatic organs. These include:
Thymus: A gland between the lungs and just below the neck;
Spleen: The organ that cleanses the blood and is located on the upper left of the abdomen.
Bone marrow: Found in the center of the bones, it also produces red blood cells.
Lymph nodes: Nominal glands in the body, which are linked by lymph vessels.
There are two main types of leukocytes:
1 – Phagocytes
These cells surround and absorb the pathogens and break down them, effectively eating them. There are several types of them, including:
Neutrophils: The most common types are phagocytes and tend to attack bacteria.
Monocytes : They are the largest and have different roles.
Macrophages : Their job is to look for pathogens and dead cells and eliminate dead cells from the body.
Mast cells : They have many jobs, including helping to heal wounds and defend against pathogens.
2 – Lymphocytes:
Lymphocytes help the body remember previous invaders and identify them if the attack comes back. Lymphocytes start their lives from bone marrow. Some remain in the brain and grow on B lymphocytes, others move to the thymus and become T lymphocytes. These two types of cells have different roles:
B lymphocytes : They produce antibodies and contribute to the function of T lymphocytes.
T lymphocytes : They kill the damaged cells in the body and help alert other leukocytes.
How does the immune system respond?
The immune system must be able to detect the outsider.It does this by detecting proteins found at the surface of all cells and learning to ignore the early proteins of its own.
In many cases, the antigen is a bacterium, fungus, virus, or foreign toxin. But it can also be one of our cells that is defective or dead.Initially, a range of cell types work together to identify the antigen as an invader.
The Role of B Lymphocytes
When they detect B antigen, they begin to produce antibodies (the antigen stands for antibody producers). Antibodies are specific proteins that bind to specific antigens.
Each B cell produces a specific antibody. For example, one may develop an antibody against the pneumonia-producing bacteria and the other may detect a cold virus.
Antibodies are part of a large family of chemicals called immunoglobulins that play many roles in the immune response:
IgG : Targets germs so other cells can deal with them.
IgM : She is an expert in killing bacteria.
IgA : It accumulates in liquids such as tears and saliva, where it protects the body’s gates.
IgE : Protects against parasites and also causes allergies.
IgD : It is restricted to B lymphocytes and helps them initiate an immune response.
Antibodies are locked on the antigen, but they do not kill and mark death. This slaughter is the work of other cells, such as phagocytes.
The role of T lymphocytes
There are different types of T lymphocytes:
T helper cells : They coordinate the immune response. Some interact with other cells and some stimulate B cells to produce more antibodies. Others absorb more T cells or phagocytes.
Killer T cells : T cells attack other cells. They are specifically for fighting viruses. By detecting small parts of the virus they work outside the infected cells and destroy the infected cells.
What is immunity?
People’s immune systems are different, but in general, they become stronger in adulthood, because at this time, the body is exposed to more pathogens and more immune.
This is why adolescents and adults are usually less ill than children. Once the antibody is produced, a copy is left in the body so that it can heal faster if the antigen reappears.
That is why, with certain diseases such as chickenpox, once infected the body has stored and prepared an antibody against chickenpox and is waiting for its destruction to enter the body again. This is called immunity.