Humoral immunity is transferred through?

Appeared in: HPSSC - 2015

Explanation

Humoral immunity, also known as antibody-mediated immunity, relies on antibodies circulating in body fluids or 'humors'.
B lymphocytes (B cells) are the immune cells responsible for producing these antibodies.
Upon encountering a specific antigen, B cells activate and differentiate into plasma cells.
Plasma cells are specialized cells that mass-produce and secrete antibodies, which then target and neutralize pathogens.

Option A: T cells are the primary agents of cell-mediated immunity, not humoral immunity. They function by directly killing infected host cells or by activating other immune cells.
Option C: Alpha cells are endocrine cells found in the islets of Langerhans within the pancreas. Their function is to secrete the hormone glucagon, which raises blood glucose levels. They have no role in the immune system.
Option D: Beta cells are also endocrine cells located in the pancreatic islets. Their function is to secrete the hormone insulin, which lowers blood glucose levels. They are not involved in immunity.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Humoral vs. Cell-Mediated Immunity as background academic context rather than a clinical decision trigger.
Vaccination is a key clinical application of humoral immunity. Most vaccines work by introducing an antigen to stimulate B cells to produce antibodies and memory cells, providing long-term protection.
Passive immunity is the direct transfer of humoral immunity. This occurs naturally when a mother passes antibodies to her baby via the placenta and breast milk, or artificially through the administration of immunoglobulins (e.g., IVIG) to treat immunodeficiency or acute infections.
What if? If a patient has an intracellular infection (like a virus hiding inside host cells), humoral immunity alone is less effective. In this case, cell-mediated immunity, driven by T cells, would be the more critical response needed to identify and destroy the infected cells.

How to Approach the Question

First, identify the core concept in the question stem, which is 'Humoral immunity'.
Recall the two major types of adaptive immunity: humoral and cell-mediated.
Associate 'humoral' with antibodies that circulate in the body's fluids ('humors').
Consider the function of each cell type listed in the options.
T cells are linked to cell-mediated immunity.
B cells are known to produce antibodies.

Concept Tested & Keywords

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E6 Pharmacology Nursing Lilley 11e Part 3 pp. 113-115, 147-149

E6 Physiology Essentials Sembulingam 10e Part 1 p. 122-124

Practise the full HPSSC - 2015

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