Our immune system is essential to our survival, without the immune system, our bodies will be available for attack from bacteria, viruses, parasites, and more. It is our immune system that maintains our health as we embark on a sea of pathogens around us.
This vast network of cells and tissues is constantly searching for invaders, and once the enemy is discovered, a complex attack is launched to eliminate them.
The immune system spreads throughout the body and includes many types of cells, organs, proteins and tissues. Crucially, it can distinguish our tissues from other tissues. The immune system also recognizes and removes dead and wrong cells.
If the immune system encounters a pathogen, for example, a bacterium, virus, or parasite, it will activate the so-called immune response. And some of the key elements of the immune system.
White blood cells
White blood cells, which are the main component of the immune system, are also called leukocytes. It is spread in the body in blood vessels and lymph vessels parallel to veins and arteries.
White blood cells work on an ongoing basis and are looking for pathogens. When they find a target, they start multiplying and sending signals to other cell types to do the same.
White blood cells are stored in different parts of the body, which are referred to as lymphatic organs. They include:
Thymus: gland between the lungs and just below the neck.
Splendid: An organ that filters blood and is located in the upper left part of the abdomen.
Bone marrow: Found in the center of the bone, it also produces red blood cells.
Lymph nodes: Small glands placed throughout the body, attached to lymphatic vessels.
There are two main types of leukocytes:
These cells absorb, break down pathogens, and effectively eat them. There are several types of them:
Neutrophils: Are the most common type of Phagocytes and tend to attack bacteria.
Monocytes: the biggest type and have several roles.
Macrophages: are cells that attack pathogens and removes dead and dying cells.
Dendritic Cells: Have many functions, including helping to heal wounds and defend against pathogens.
Lymphocytes help the body remember and identify ex-invaders if they return to attack again. Lymphocytes begin their life in the bone marrow. Some remain in the marrow and develop into B lymphocytes (B cells), while others turn to the thymus gland and become T lymphocytes (T cells). These two types of cells have different roles:
B lymphocytes: Produces antibodies and helps alert T lymphocytes.
T lymphocytes: Destroy endangered cells in the body and help alert other leukocytes.
How the immune system response works
The immune system should be able to distinguish natural tissues from alien tissues. This is done by detecting proteins on the surface of all cells. it learns to ignore its own proteins at an early stage so that they are not attacked wrongly in the future.
Antigen is any substance that can provoke an immune response.
In many cases, the antigen is bacteria, fungi, virus, poison, or a foreign body. But it can also be one of our defective or dead cells. Initially, a group of cell types work together to identify the antigen as an invader and activate the immune system against it.
The role of B lymphocytes
Once the Antigens are detected by B lymphocytes, they begin to excrete antibodies. Antibodies are special proteins that are associated with certain antigens with the aim of eliminating them.
Each B cell creates a specific antibody. For example, one antibody may be made against the bacteria that cause pneumonia, and the other may recognize the virus.
Antibodies are part of a large family of chemicals called immunoglobulin, which play many roles in immune response.
The role of T lymphocytes
There are distinct types of T lymphocytes:
T-cells: The immune system’s response coordinates as some of its cells communicate with other cells, and some stimulate B cells to produce more antibodies. Others attract more T-cells or cell-eating pharyngeal cells.
Deadly T-cells: As the name suggests, these T-cells attack other cells. They are particularly useful for anti-virus. It works by identifying small parts of the virus outside the infected cells and destroying infected cells.
Everyone’s immune system varies, but, as a rule, the immune system becomes stronger during adulthood, as we were exposed at that time to more pathogens that greatly helped our immune system grow.
This is why adolescents and adults tend to get less sick than children.
Once an antibody is produced, a copy remains in the body so that if the same antigen appears again, it can be treated more quickly.
This is also the cause of some diseases, such as chickenpox, which is only once because the body has an anti-chickenpox body, ready and waiting to be destroyed the next time it arrives. This process is called immunity.
There are three types of immunity in humans called fungal, adaptive and negative:
Innate immunity: We have all been born with a certain level of immunity for invaders. Human immune systems, like those found in many animals, will attack foreign invaders from day one. This innate immunity includes the external barriers of our body – the first line of defense against pathogens – such as the skin and mucous membranes in the throat and intestines. This response is more general and undefined. If the pathogen manages to avoid the innate immune system, negative or acquired immunity begins to be addressed.
Adaptive (acquired) immunity: This protection from pathogens develops as we progress in life. When we are exposed to diseases or take the vaccine, we build a library of antibodies to various pathogens. This is sometimes referred to as immune memory because our immune system remembers former enemies.
Negative immunity: This type of immunity is “borrowed” from another source, but it does not last indefinitely. For example, the baby receives antibodies from the mother through the placenta before birth and in breast milk after birth. This negative immunity protects the child from certain infections during the early years of life.
provides antigens or weak pathogens to the person so that the individual does not get sick but still produces antibodies. Since the body preserves copies of antibodies, it is protected if the threat must appear again later in life.
Immune system disorders
Because the immune system is very complex, there are many possible ways that can go wrong. Types of immune disorders are divided into three categories:
HIV: These arise when one or more parts of the immune system do not work. Immunodeficiency conditions can occur in several ways, including age, obesity and alcoholism. In developing countries, malnutrition is a common cause. AIDS is an example of HIV.
In some cases, HIV conditions can be inherited, for example, in chronic granular diseases where the swallowing cells do not function properly.
Autoimmune: In autoimmune situations, the immune system accidentally targets healthy cells, rather than foreign pathogens or defective cells. In this scenario, they cannot distinguish normal cells from alien cells.
Autoimmune diseases include celiac disease, type 1 diabetes, rheumatoid arthritis and Graves’ disease.
Hypersensitivity: With hypersensitivity, the immune system overreacts in a way that harms healthy tissues. An example is an allergic shock where the body responds to allergens so severely that it can be life-threatening.