<h2>Definition of Antibodies</h2>

Antibodies, also known as immunoglobulins, are specialized protein molecules that are produced by the immune system in response to the presence of foreign substances, called antigens, in the body. These substances can be anything from harmful bacteria and viruses to toxins and other foreign particles.

Types of Antibodies

There are five major types of antibodies, each with a specific function within the immune system:

  1. IgG: Immunoglobulin G is the most abundant antibody, accounting for approximately 75% of all antibodies in the human body. It plays a crucial role in providing long-term immunity against infections.
  2. IgM: Immunoglobulin M is the first antibody produced by the body during an initial encounter with an antigen. It is responsible for activating other components of the immune system.
  3. IgA: Immunoglobulin A is mainly found in mucosal areas such as the respiratory and gastrointestinal tracts. It helps defend against pathogens that enter through these mucosal surfaces.
  4. IgE: Immunoglobulin E is involved in allergic reactions and provides defense against parasitic infections. It triggers the release of histamine, causing symptoms like itching, swelling, and inflammation.
  5. IgD: Immunoglobulin D is present in very low levels in the bloodstream. Its exact function is still not fully understood, but it may play a role in the activation of B cells.

Function of Antibodies

Antibodies work by recognizing specific antigens on the surface of foreign substances and binding to them. This binding process helps in neutralizing the antigens directly, marking them for destruction by other immune cells, and activating other immune responses.

Production of Antibodies

Antibodies are produced by B lymphocytes, a type of white blood cell. When B lymphocytes encounter an antigen, they undergo a process called differentiation and turn into plasma cells. Plasma cells then secrete large quantities of antibodies into the bloodstream to combat the particular antigens.

Antibodies in Medical Diagnostics

The presence of specific antibodies in blood serum is often used in medical diagnostics to determine if an individual has been exposed to particular infections or diseases. Antibody tests can help diagnose various conditions, monitor responses to treatments, and assess immunity levels.

Conclusion

Antibodies play a vital role in the immune system’s defense against pathogens and foreign substances. By recognizing and binding to antigens, they initiate immune responses that protect the body from infections and disease.