A patient in septic shock shows signs of cortical necrosis in the kidneys. Which nephron structure is most likely to be affected?

• A. Collecting ducts
• B. Loop of Henle
• C. Proximal convoluted tubules
• D. Papillary ducts

Answer: (C)

In the context of septic shock and its impact on the kidneys, cortical necrosis typically affects areas of the nephron that are particularly susceptible to ischemia due to their high metabolic activity and oxygen demand. The proximal convoluted tubules are critical in reabsorbing nutrients, electrolytes, and water from the filtrate, which requires significant energy.

During septic shock, there is often a reduction in renal blood flow and subsequent ischemia, particularly affecting the outer cortex of the kidney where the proximal convoluted tubules are located. These cells are not only metabolically active but also vulnerable to ischemic injury, rendering them the most likely nephron structure to be damaged in this scenario.

While the other structures, such as the collecting ducts, loop of Henle, and papillary ducts, play important roles in kidney function, they are less susceptible to the immediate ischemic effects seen in septic shock when compared to the proximal convoluted tubules. In summary, the combination of high metabolic demands and specific anatomical location makes the proximal convoluted tubules the most likely nephron structure affected in cases of cortical necrosis due to septic shock.