AEMCA Practice Exam

What is erythropoietin and where is it released from?

1. A hormone released from the spleen that stimulates white blood cell production

2. A hormone released from the liver that stimulates RBC production

3. A type of enzyme released from the pancreas

4. A neurotransmitter released by nerve cells

The correct answer is: A hormone released from the liver that stimulates RBC production

Erythropoietin is a glycoprotein hormone primarily produced and released by the kidneys, although it is often discussed in the context of systemic production involving other organs, such as the liver during fetal development. Its main function is to stimulate the production of red blood cells (RBCs) in the bone marrow in response to low oxygen levels in the blood, a condition known as hypoxia. The answer specifically stating that erythropoietin is released from the liver does not accurately describe its principal source, which is mostly the kidneys in adults. Therefore, acknowledging the importance of the kidneys in this hormonal response is crucial for understanding its role in erythropoiesis (the formation of red blood cells). The other options mention processes or functions that are unrelated to erythropoietin. For instance, the spleen is more involved in filtering blood and recycling iron from hemoglobin rather than producing erythropoietin or stimulating white blood cells. Enzymes from the pancreas are associated with digestion and metabolic processes, not with red blood cell production. Lastly, neurotransmitters are chemical messengers used by nerve cells to communicate, which is entirely different from the role of erythropoietin in hematopoiesis