Which definition pertains to intra-renal failure?

Intra-renal failure, also known as intrinsic renal failure, specifically refers to kidney dysfunction that arises from issues within the kidney tissue itself, particularly affecting the renal cortex or medulla. Conditions like acute tubular necrosis, glomerulonephritis, and certain nephrotoxins are classic examples where the structure and function of the renal cells are impaired, leading to a decline in the kidneys' ability to filter waste and maintain fluid and electrolyte balance.

This understanding distinguishes intra-renal failure from other types of renal failure, such as pre-renal failure, which is caused by factors that affect blood flow to the kidneys, and post-renal failure, resulting from obstructions in the urinary tract. In particular, pre-renal failure is linked to impaired renal perfusion, while systemic dehydration and shock play a direct role in pre-renal conditions rather than intra-renal. The relationship between prolonged hypertension and kidney damage usually pertains to chronic kidney disease rather than acute intra-renal failure. Thus, the definition focusing on disorders affecting the renal cortex or medulla is the most accurate description of intra-renal failure.