Acquired, Innate, Cell-mediated & humoral Immunity
Acquired immunity refers to the body's ability to recognize and remember specific pathogens, achieved through exposure or vaccination, while innate immunity provides immediate, non-specific defences, and cell-mediated and humoral immunity involves specialized cells and antibodies in the adaptive immune response.
Certainly! Immunity can be categorized into different types, including
acquired,
innate,
cell-mediated, and
humoral immunity.
Let's explore each of these types of immunity acquired Immunity
Acquired immunity, also known as adaptive immunity, is a type of immunity that the body develops after exposure to a specific pathogen or through vaccination. It is highly specialized and has memory, allowing the immune system to recognize and respond more effectively upon re-exposure to the same pathogen.
Acquired immunity can be divided into two main branches:
Cell-Mediated Immunity: This branch of acquired immunity involves the action of immune cells, particularly T cells. When T cells encounter infected or abnormal cells, they respond by killing these cells. Cell-mediated immunity is crucial for defending against intracellular pathogens, such as viruses.
Humoral Immunity: Humoral immunity, on the other hand, is mediated by B cells. B cells produce antibodies (immunoglobulins) that can neutralize pathogens like bacteria and viruses by binding to their surface. These antibodies can also mark pathogens for destruction by other immune cells. Humoral immunity is particularly effective against extracellular pathogens.
Innate Immunity
Innate immunity is the body's immediate, non-specific defence mechanism. It acts as the first line of defence against pathogens, even before the immune system has encountered a specific invader. Innate immunity includes physical and chemical barriers, such as the skin and mucous membranes, as well as various white blood cells like neutrophils and macrophages. These cells are always on the lookout for signs of trouble and can quickly respond to a wide range of pathogens. Innate immunity is important for controlling the initial stages of infection.
Cell-Mediated Immunity
Cell-mediated immunity is a component of acquired immunity, as mentioned earlier. It involves the action of T cells, particularly cytotoxic T cells and helper T cells. Here's how it works:
Cytotoxic T Cells (CD8+ T Cells): These are specialized killer cells. When they encounter cells that are infected by a virus or other intracellular pathogens, they recognize and destroy these infected cells. This prevents the further spread of the infection.
Helper T Cells (CD4+ T Cells): Helper T cells are like the conductors of the immune orchestra. They help coordinate the immune response by releasing signalling molecules called cytokines. These molecules guide other immune cells to the site of infection and assist B cells in antibody production.
Cell-mediated immunity is particularly important for combating intracellular pathogens, including viruses, and for responding to abnormal cells, such as cancer cells.
Humoral Immunity:
Humoral immunity is the other branch of acquired immunity, involving B cells and antibodies. Here's how it works:
B Cells: B cells are white blood cells that, when activated, differentiate into plasma cells. These plasma cells produce antibodies specific to a particular pathogen's antigens.
Antibodies (Immunoglobulins): Antibodies are proteins produced by B cells. They can neutralize pathogens by binding to them, making it easier for other immune cells to eliminate the invaders. Antibodies are highly specific to the antigens on the pathogen's surface.
Humoral immunity is effective against extracellular pathogens, such as bacteria, as well as toxins produced by these pathogens.
In summary, the immune system relies on acquired and innate immunity to protect the body from various threats. Acquired immunity can be further divided into cell-mediated and humoral immunity, each with its specific roles and mechanisms. Understanding these types of immunity is key to comprehending how the immune system functions and protects our health.
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