Biological Systems MCAT Practice Exam 2025 – The Comprehensive All-in-One Guide for Exam Success!

The primary function of erythropoietin is to stimulate red blood cell production. This glycoprotein hormone is primarily produced by the kidneys in response to low oxygen levels in the blood (hypoxia). When the body senses decreased oxygen availability, erythropoietin is released into the bloodstream, where it acts on the bone marrow to encourage the differentiation and proliferation of precursor cells into mature red blood cells. This response is crucial for increasing the oxygen-carrying capacity of the blood, thus helping to maintain adequate oxygen levels in the body’s tissues.

The mechanisms that govern this hormone's action are vital for ensuring that the body can adapt to varying levels of oxygen demand, such as during exercise or at high altitudes. Enhanced red blood cell production directly correlates with improvements in oxygen delivery throughout the body, which is why erythropoietin plays a key role in maintaining homeostasis and supporting overall health.