Smallest cell in cellular component of blood is?

Appeared in: BSF Staff Nurse - 2021

Explanation

Platelets, also known as thrombocytes, are the smallest of the blood's formed elements.
Their diameter ranges from 2 to 4 micrometers (µm), making them significantly smaller than both red and white blood cells (SRC_12121).
Although technically fragments of larger cells (megakaryocytes), they are considered a primary cellular component alongside RBCs and WBCs (SRC_12120).
Their primary function is to initiate blood clotting and maintain hemostasis.

Option B: Red Blood Cells (RBCs) are larger than platelets, with a typical diameter of 7–8 µm (SRC_12120).
Option C: White Blood Cells (WBCs) are the largest of the blood cells, with sizes ranging from 8 to 20 µm depending on the specific type (e.g., lymphocyte vs. monocyte).
Option D: This option is incorrect because there is a distinct size difference among the cellular components, and only one can be the smallest.

Clinical Relevance

Nursing practice connection: Knowing Relative sizes of blood cellular components helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
A nurse must understand the significance of the platelet count in a complete blood count (CBC) report. The normal range is typically 150,000 to 450,000 platelets per microliter of blood.
A low platelet count (thrombocytopenia) increases the risk of bleeding, and nurses must implement bleeding precautions. A high platelet count (thrombocytosis) increases the risk of forming unwanted blood clots (thrombosis).
What if? If a patient's platelet count drops below 50,000/µL, a nurse should anticipate holding orders for anticoagulant medications, avoid invasive procedures like intramuscular injections, and monitor closely for signs of bleeding (e.g., petechiae, ecchymosis, hematuria).

How to Approach the Question

First, identify the core of the question, which is asking to compare the size of the 'cellular components of blood'.
Recall the three main formed elements in blood: platelets (thrombocytes), red blood cells (erythrocytes), and white blood cells (leukocytes).
Access your knowledge about the relative sizes of these components. Remember that platelets are cell fragments and are the smallest.
Compare the options: Platelets (smallest), RBCs (medium-sized), and WBCs (largest).
Based on this comparison, select 'Platelets' as the correct answer.
Eliminate 'All of the above' as it's illogical for a question asking for the 'smallest'.

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 1 Part 3 p. 110-111

E6 Physiology Essentials Sembulingam 10e Part 1 p. 130-132

Practise the full BSF Staff Nurse - 2021

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