Question

What is the function of lymphocytes?

Short answer

Lymphocytes are white blood cells that serve to recognize antigens, produce antibodies, form memory lymphocytes, and are involved in cell-mediated immunity.

Step-by-step solution

Definition of Lymphocytes

Lymphocytes are a type of white blood cell in the immune system that are the body's main type of immune cell. They are classified as part of the adaptive immune system because they come into play when the body is exposed to pathogens it has seen before.

Function of Lymphocytes

Lymphocytes have three main functions: 1) They produce antibodies that are used to neutralize pathogens such as bacteria and viruses. 2) They serve to recognize antigens, produce antibodies, and form memory lymphocytes. 3) They are involved in cell-mediated immunity, where the immune system kills the body's own cells that have been infected with viruses or become cancerous.

Key concepts

Adaptive Immune System

The adaptive immune system is a sophisticated defense mechanism that provides pinpoint protection against pathogens. Unlike the innate immune system, which offers general defense, the adaptive system specifically recognizes and responds to unique antigens. The highlight of this system includes its ability to remember past invaders.

Lymphocytes, such as B cells and T cells, are the primary players in this system. They are like soldiers undergoing special training to target a specific enemy, which in this case, are the harmful invaders like bacteria and viruses. When a pathogen enters the body, these cells swing into action, remembering past interactions with the same foe, to mount a quicker and more powerful response.

Antibodies Production

Antibodies are the body's precision-guided weapons in the battle against diseases. These Y-shaped proteins are produced by B lymphocytes, a type of white blood cell. When a harmful microorganism invades the body, B cells recognize it and start producing specific antibodies.

These antibodies lock onto the antigens like a key in a lock, signaling other immune cells to destroy the pathogen, or neutralizing it directly. An amazing feature of antibody production is that after an infection or vaccination, 'memory' B cells remain vigilant, ready to produce antibodies quickly if the same pathogen invades again.

Cell-Mediated Immunity

While B cells and antibodies handle pathogens outside the cells, cell-mediated immunity deals with threats inside host cells. This type of immunity involves different classes of T lymphocytes, including Killer T cells, Helper T cells, and Regulatory T cells.

Killer T cells, also known as cytotoxic T cells, seek out and destroy infected or cancerous cells. They use special receptors to recognize cells that display abnormal or foreign proteins on their surfaces, then release powerful enzymes to kill these compromised cells, protecting the body from further harm.

Antigen Recognition

Antigen recognition is the immune system's way of detecting invaders. An antigen is any substance that triggers an immune response, often a protein on the surface of pathogens or infected cells. Lymphocytes are equipped with unique receptors that can each bind to a specific antigen.

When a lymphocyte's receptor finds its matching antigen, it sends a signal inside the cell to take action. This can include the production of antibodies, the killing of infected cells, or the activation of other immune cells. The specificity of antigen recognition is what ensures that the immune response targets only harmful intruders without damaging the body’s own tissues.