Certified Dialysis Nurse Practice Test

The choice of erythropoietin as the hormone synthesized by the kidney is accurate because erythropoietin is a glycoprotein hormone produced primarily by renal peritubular interstitial cells in response to hypoxia (low oxygen levels) in the blood. Its main function is to stimulate the production of red blood cells in the bone marrow, thereby increasing the oxygen-carrying capacity of the blood. This makes it a crucial hormone for maintaining adequate oxygen levels in the body, particularly in conditions where oxygen supply is compromised.

In contrast, the other hormones listed are produced by different organs: insulin is synthesized by the pancreas and regulates blood glucose levels; cortisol, a steroid hormone, is produced by the adrenal glands and plays a role in stress response and metabolism; and thyroxine is secreted by the thyroid gland and is vital for regulating metabolism and growth. This delineation underscores the unique role the kidneys play in hormone synthesis, particularly in response to the body's oxygen needs.