Which cell secretes antibodies?

Appeared in: MP CHO -2019 (Shift-1)

Explanation

Lymphocytes are a category of white blood cells central to the adaptive immune system.
A specific type, B-lymphocytes, are responsible for humoral immunity.
Upon activation by a foreign antigen, B-lymphocytes differentiate into plasma cells.
Plasma cells are specialized factories that produce and secrete large quantities of proteins called antibodies (immunoglobulins), which target specific pathogens.

Option A: Monocytes are phagocytic cells that engulf pathogens and cellular debris. They can differentiate into macrophages and dendritic cells to present antigens to T-cells, but they do not secrete antibodies.
Option C: Neutrophils are the most abundant type of white blood cell and are the primary responders to acute bacterial infections. Their main function is phagocytosis (engulfing and destroying bacteria). They do not produce antibodies.
Option D: Eosinophils are primarily involved in combating multicellular parasitic infections (like worms) and play a significant role in modulating allergic inflammatory responses. They do not secrete antibodies.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Functions of Leukocytes (White Blood Cells) as background academic context rather than a clinical decision trigger.
Measuring specific antibody levels in a patient's blood is a fundamental diagnostic tool for identifying past or current infections (e.g., COVID-19, HIV, hepatitis) and assessing immune status.
Vaccination is a cornerstone of public health that works by stimulating B-lymphocytes to produce memory cells and antibodies, providing long-term protection against specific diseases without causing the illness.
What if? If a patient had a genetic disorder preventing B-cells from differentiating into plasma cells (e.g., Common Variable Immunodeficiency), they would have very low antibody levels, leading to recurrent and severe bacterial infections. Treatment would involve regular infusions of immunoglobulins.

How to Approach the Question

This is a factual recall question testing knowledge of hematology and immunology.
First, identify the key action in the question stem: 'secretes antibodies'.
Next, review the options, which are all types of white blood cells (leukocytes).
Systematically recall the primary function of each cell type.
Monocytes and Neutrophils are primarily phagocytes (cell eaters).
Eosinophils are associated with parasites and allergies.

Concept Tested & Keywords

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E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 654-656

E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) p. 105-107

E6 Anatomy Applied Ashalatha 4e p. 154-156

Practise the full MP CHO -2019 (Shift-1)

Attempt every question from this paper in a timed mock, then review the full solution for each one.