25-45% of all White blood cells are?

Appeared in: PGICH Noida NO-2025

Explanation

Lymphocytes constitute about 16-45% of the total white blood cell count in adults, which aligns with the 25-45% range provided in the question.
These cells are a type of agranulocyte and are fundamental to the body's adaptive immune response.
Lymphocytes are categorized into T cells (mediating cellular immunity), B cells (mediating humoral immunity by producing antibodies), and Natural Killer (NK) cells.

Option A: Basophils are the least common type of WBC, making up only 0-2% of the total count, which is significantly lower than the 25-45% range.
Option B: Eosinophils typically account for 1-6% of the total WBC count. This percentage is far below the 25-45% range specified.
Option C: Monocytes constitute about 2-10% of the total WBC count, a range that does not overlap with 25-45%.

Clinical Relevance

Nursing practice connection: Knowing Normal differential count of White Blood Cells (WBCs) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding the normal WBC differential is a fundamental skill for nurses, enabling them to interpret lab results and identify potential signs of infection, inflammation, autoimmune diseases, or hematological malignancies.
A deviation from the normal range for any WBC type is a critical finding. For instance, lymphocytosis (high lymphocyte count) often points to a viral infection, while lymphopenia (low lymphocyte count) can indicate an immune system deficiency.
What if? If a patient's lab report showed a lymphocyte count of 70%, a nurse should recognize this as significant lymphocytosis. This finding would warrant prompt notification of the physician as it could indicate a serious condition such as chronic lymphocytic leukemia (CLL) or an acute viral infection like mononucleosis.

How to Approach the Question

This is a factual recall question that tests your knowledge of hematology.
First, identify the key information in the stem: the percentage range '25-45%' and the cell type 'White blood cells'.
Systematically recall the normal differential count (percentage ranges) for the five main types of leukocytes: Neutrophils, Lymphocytes, Monocytes, Eosinophils, and Basophils.
Compare the given percentage range (25-45%) with the known normal range for each option.
Eliminate the options with ranges that do not match: Basophils (<2%), Eosinophils (1-6%), and Monocytes (2-10%).
Confirm that the normal range for Lymphocytes (approximately 20-45%) includes the range specified in the question, making it the correct answer.

Concept Tested & Keywords

Qh4BArOs25F_sI3wf_nHu6

E6 Anatomy Applied Ashalatha 4e p. 154-156

E6 Medicine Harrison 22e Part 1 p. 494-496

Practise the full PGICH Noida NO-2025

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