Immune system functions
What is the immune system?
The immune system is our body's DEFENSE mechanism against infections; it is capable of detecting and attacking harmful agents, such as microorganisms, and helps us stay healthy.
What makes up this system?
Many cells and organs work in synergy to protect the body. White blood cells, technically called leukocytes, play a key role in it. Some of them are called phagocytes, which devour invading organisms. Others are lymphocytes; within which there are two types: B lymphocytes and T lymphocytes. Both are produced in the bone marrow and remain there until they mature; after this, they can take two possible paths: Become B lymphocytes and act as an intelligence system in the body, detecting and immobilizing invaders. Travel to the thymus gland and mature there to become T lymphocytes, which attack and destroy the invaders.
How does the immune system work?
When the body detects that foreign substances (antigens) have infiltrated, the immune system begins its work by recognizing them to subsequently eliminate them.
B lymphocytes manufacture antibodies, a type of protein in charge of locating and paralyzing specific antigens. These have the ability to remain in the body, so when the immune system identifies an invasion of that antigen again, it already has a defense method against them. This explains why some diseases often only occur once in people.
In fact, vaccines work under the previous concept, since they are doses of antigens that are supplied to the body in small amounts that cannot cause disease, but which do serve to teach the organism the behavior of the agent so that our immune system can react to it in the event of possible attacks in the future.
Although antibodies can recognize antigens and immobilize them, they do not have the ability to destroy them on their own; that is the responsibility of T lymphocytes. But that is not their only responsibility, as they also eliminate those cells that have been infected with a microorganism or that have changed for some reason. Some T lymphocytes are called “natural killer cells”.
Other functions of antibodies in the body are:
Neutralizing poisonous substances or toxins to minimize their action. Activating the complement system, which is also part of the immune system and is responsible for destroying bacteria, viruses, and infected cells.
All these types of cells work tirelessly to protect the body from contracting different types of diseases. This protection is called IMMUNITY.
In humans, there are 3 types of immunity: innate, adaptive, and passive.
Innate immunity:
It is the one we are all born with and refers to a type of general defense. An example of this is the skin, which serves as a natural barrier that prevents the entry of invading agents.
Adaptive immunity:
It is the one we develop over time, as we are exposed to different diseases or when we receive a vaccine. In this type of immunity, the body learns to identify and memorize the agents that cause it and how to react to it.
Passive immunity:
It is a type of temporary immunity that does not belong to us completely but provides us with a benefit. It normally comes from an external source and lasts for a short time. The antibodies contained in breast milk are, for example, a type of passive immunity, as it is responsible for protecting the baby from contracting certain diseases to which its mother had already been exposed before.
Bibliographic references consulted:
https://kidshealth.org/es/parents/immune-esp.html?ref=search
By: Camila Henao Uribe Nutritionist Dietitian– Funat Laboratories