What is the main purpose of White Blood Corpuscles (WBCs)?

Appeared in: UP CHO - 2018

Explanation

The primary role of White Blood Corpuscles (WBCs), or leukocytes, is to serve as the body's main line of defense against foreign invaders.
As stated in medical literature, WBCs are the 'body's soldiers that provide defense and immunity from invading organisms.'.
They achieve this by identifying and destroying pathogens (like bacteria and viruses) through processes such as phagocytosis (engulfing pathogens) and by producing antibodies.
Different types of WBCs, such as neutrophils and lymphocytes, have specialized roles in the immune response.

Option A: This is the primary function of blood plasma, the liquid component of blood, which transports dissolved nutrients, hormones, and proteins.
Option C: This is the specific function of Red Blood Cells (RBCs), which contain the protein hemoglobin that binds to and transports oxygen from the lungs to the tissues.
Option D: Physical strength is a result of musculoskeletal health and overall nutrition, not a direct physiological function of any single type of blood cell.

Clinical Relevance

Nursing practice connection: Knowing Function of White Blood Corpuscles (WBCs) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
A nurse monitors a patient's WBC count as a key indicator of infection. An elevated count (leukocytosis) often signals a bacterial or viral infection, while a low count (leukopenia) can indicate a compromised immune system.
Understanding the function of WBCs is crucial for interpreting lab results (Complete Blood Count - CBC) and making clinical decisions about infection control, antibiotic therapy, and patient isolation.
What if a patient undergoing chemotherapy has a critically low WBC count (neutropenia)? The nurse must implement neutropenic precautions (e.g., strict hand hygiene, avoiding fresh flowers/raw foods, wearing a mask) to protect the patient from life-threatening infections, as their ability to 'combat infection' is severely impaired.

How to Approach the Question

First, identify the key subject of the question, which is 'White Blood Corpuscles (WBCs)'.
Next, recall the primary physiological functions of the main components of blood.
Evaluate each option against this knowledge. Ask yourself: 'Is this the main job of a WBC?'
Option A (nutrients) is plasma. Option C (oxygen) is RBCs. Option D (strength) is too general. This leaves Option B.
Confirm that 'to combat infection' is the well-known primary function of the immune system, of which WBCs are the main cellular component.

Concept Tested & Keywords

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E6 Anatomy Applied Ashalatha 4e p. 153-155

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 648-650

E6 Physiology Essentials Sembulingam 10e Part 1 p. 114-116

Practise the full UP CHO - 2018

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