Life span of platelets is?

Appeared in: ISRO- 2016

Explanation

The average lifespan of platelets (thrombocytes) in circulation is 8 to 12 days, with many texts citing a range of 7 to 10 days.
Platelets are produced in the bone marrow from large cells known as megakaryocytes.
Following their circulation, they are cleared by macrophages, predominantly in the spleen and liver.
This lifespan is significantly shorter than that of red blood cells, which circulate for about 120 days.

Option A: This range is too broad and inaccurate. It incorrectly includes the 120-day lifespan of red blood cells.
Option B: This duration is too short for the normal lifespan of a platelet in a healthy individual.
Option D: This is an extremely short and incorrect lifespan for a platelet. Some white blood cells, like neutrophils, have very short lifespans in circulation (hours), but not platelets.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Lifespan of Platelets as background academic context rather than a clinical decision trigger.
Knowledge of platelet lifespan is essential for managing conditions like thrombocytopenia (low platelet count) and determining the appropriate frequency of platelet transfusions.
It is also critical for understanding the duration of action of antiplatelet medications. For example, the effect of a single dose of aspirin lasts for the entire 8-12 day lifespan of the affected platelets.
What if? If a patient has an enlarged spleen (splenomegaly), the platelet lifespan can be significantly shortened. The spleen is a primary site of platelet destruction, and an overactive or enlarged spleen can trap and destroy platelets at an accelerated rate, leading to thrombocytopenia.

How to Approach the Question

This is a factual recall question common in physiology and hematology.
First, identify the key term in the question, which is 'lifespan of platelets'.
Recall the standard physiological value for the lifespan of platelets from your studies.
Compare the recalled value (typically 7-10 or 8-12 days) with the options provided.
Select the option that most closely matches the known fact. In this case, '8–12 days' is the correct choice.
Mentally eliminate the other options by comparing them to known lifespans of other blood cells (e.g., 120 days for RBCs) to confirm your answer.

Concept Tested & Keywords

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E6 Medicine Harrison 22e Part 1 p. 978-980

E6 Physiology Guyton 4SAE Part 1 p. 172-174

Practise the full ISRO- 2016

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