Erythropoietin is produced by?

Appeared in: JSSH Staff Nurse - 2019

Explanation

Erythropoietin (EPO) is a crucial hormone that controls the rate of red blood cell (RBC) production, a process known as erythropoiesis.
In adults, the vast majority (approximately 90%) of EPO is produced and secreted by specialized cells within the kidneys.
The primary stimulus for the kidneys to release EPO is tissue hypoxia, or low oxygen levels.
Once released, EPO acts on the bone marrow to stimulate the development of RBCs, thereby increasing the oxygen-carrying capacity of the blood.

Option A: The lungs are the site of gas exchange, where oxygen enters the blood. While chronic lung disease can cause hypoxia that stimulates EPO production, the lungs themselves do not produce the hormone.
Option B: The small intestine is primarily involved in the digestion and absorption of nutrients. It absorbs essential components for RBC formation like iron, vitamin B12, and folic acid, but it does not synthesize EPO.
Option C: The liver is a secondary site for EPO production in adults, contributing only about 10% of the total amount. The kidneys are the primary source.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Site of erythropoietin (EPO) production as background academic context rather than a clinical decision trigger.
In patients with chronic kidney disease (CKD), the damaged kidneys fail to produce sufficient EPO, leading to anemia. Nurses must monitor these patients for fatigue, pallor, and shortness of breath.
Treatment for anemia of CKD involves administering synthetic EPO (erythropoiesis-stimulating agents or ESAs) to stimulate red blood cell production.
Monitoring hemoglobin and hematocrit levels is a key nursing responsibility for patients on ESA therapy to ensure effectiveness and avoid complications like hypertension or thrombosis from excessively high RBC counts.

How to Approach the Question

Identify the key term in the question: 'Erythropoietin'.
Recognize this as a factual recall question about the origin of a specific hormone in the human body.
Systematically review the function of each organ listed in the options in the context of hormone production.
Recall that the kidneys have major endocrine functions, including the production of erythropoietin and renin.
Differentiate between the primary site (kidneys) and the secondary site (liver) of production in adults to select the most accurate answer.

Concept Tested & Keywords

QvhHZLBIKgL_BWNWc94pCl

E6 Physiology Guyton 4SAE Part 1 p. 177-179

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 640-642

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart B (pp 240-463 of 478) p. 157-159

Practise the full JSSH Staff Nurse - 2019

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