USMLE (United States Medical Licensing Examination) Step 1 Practice Exam

Acute Tubular Necrosis (ATN) is a condition that leads to the death of tubular cells in the kidney, resulting in a decline in kidney function. One of the most prominent presentations of ATN is acute renal failure, which occurs when the kidneys suddenly lose their ability to filter waste products from the blood effectively.

In ATN, there is typically a significant level of damage to the renal tubules, often caused by ischemia, nephrotoxins, or other insults, which leads to an abrupt decline in the glomerular filtration rate (GFR). This decrease in GFR is characterized by the rise in serum creatinine and blood urea nitrogen (BUN) levels, clinical indicators of acute renal failure.

While conditions like renal artery stenosis or processes involving glomerulotubular balance and isosmotic reabsorption are related to kidney function, they do not directly describe the state or consequence of acute tubular necrosis. In contrast, acute renal failure is a direct outcome of the tubular injury during ATN, making it the most relevant association with this condition.