Antibodies are produced by?

AIIMS BBSR SNO - 2019

Applied Physiology

Easy

Appeared in: AIIMS BBSR SNO - 2019

Explanation

B lymphocytes (B cells) are the precursors to plasma cells.
Upon activation by an antigen, B cells differentiate into plasma cells.
Plasma cells are specialized factories that produce and secrete large quantities of antibodies (immunoglobulins).
This process is the foundation of humoral immunity, which targets extracellular pathogens and toxins.

Option A: Natural Killer (NK) cells are part of the innate immune system and do not produce antibodies. Their primary role is to identify and destroy abnormal cells, such as tumor cells or cells infected with viruses, through direct cytotoxic action.
Option B: Neutrophils are the most abundant type of white blood cell and are a key component of the innate immune system. Their main function is phagocytosis—engulfing and digesting pathogens like bacteria. They do not produce antibodies.
Option C: T lymphocytes (T cells) are central to cell-mediated immunity. They have various roles, including helping to activate B cells (Helper T cells) and directly killing infected host cells (Cytotoxic T cells), but they do not produce antibodies themselves.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cellular origin of antibodies and functions of different leukocytes as background academic context rather than a clinical decision trigger.
Understanding that B cells produce antibodies is fundamental to comprehending how vaccines work. Vaccines introduce antigens to stimulate B cells to produce antibodies and memory cells, providing long-term immunity.
In a clinical setting, nurses may care for patients with immunodeficiency disorders like agammaglobulinemia, where there is a lack of B cells and antibodies. These patients require immunoglobulin replacement therapy (IVIG) and strict infection control measures.
What if? If a patient had a severe T-cell deficiency (like in advanced HIV/AIDS), their ability to produce antibodies would also be severely impaired. This is because Helper T cells are often required to fully activate B cells to become antibody-producing plasma cells.

How to Approach the Question

Identify the core concept of the question, which is 'antibody production'.
Mentally review the main types of leukocytes (white blood cells) and their primary functions.
Associate 'B' lymphocytes with 'antiBodies'. This is a common and effective mnemonic.
Eliminate the other options based on their distinct roles: T cells for cell-mediated immunity, Neutrophils for phagocytosis, and NK cells for innate cytotoxic activity.
Confirm that B cells differentiate into plasma cells, which are the actual antibody factories, solidifying the choice.

Concept Tested & Keywords

Concept Tested: Cellular origin of antibodies and functions of different leukocytes.
Stem keywords: Antibodies, produced by
Lead-in keywords: BEST, MOST RELEVANT CLUE

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