Which pathophysiologic process causes redness with acute inflammation?

Choice A reason: Cortisol, a stress hormone, suppresses immune and inflammatory responses, slowing fibroblast activity and collagen synthesis, which impairs wound healing. This anti-inflammatory effect prioritizes energy allocation to stress response over tissue repair, making decreased wound healing a correct effect of cortisol during stress.

Choice B reason: Cortisol stimulates gastric acid secretion by enhancing gastrin release and reducing mucosal protection, increasing the risk of ulcers. This effect supports energy mobilization during stress by promoting digestion but can lead to gastrointestinal complications, making increased gastric acid secretion a correct effect.

Choice C reason: Cortisol promotes gluconeogenesis and glycogenolysis in the liver, elevating blood glucose levels to provide energy for the stress response. It also induces insulin resistance, ensuring glucose availability for critical tissues like the brain, making increased blood glucose a correct effect of cortisol.

Choice D reason: Cortisol suppresses the immune response by inhibiting cytokine production and lymphocyte proliferation, reducing inflammation and immune activity. This does not align with increased immune response, as cortisol’s immunosuppressive effects are well-documented, making this choice incorrect for the stress response.

Choice E reason: Cortisol increases blood pressure via mineralocorticoid effects, enhancing sodium retention and vascular tone. This supports cardiovascular stability during stress, not decreased blood pressure, which would be counterproductive in a fight-or-flight response, making this choice incorrect for cortisol’s effects.

Choice A reason: Pyelonephritis, a bacterial kidney infection, causes intrarenal AKI by directly damaging renal parenchyma through inflammation and tubular injury. The infection disrupts nephron function, reducing filtration and leading to acute kidney injury, making this a correct cause of intrarenal damage.

Choice B reason: Nephrotoxins, such as certain drugs or chemicals, cause intrarenal AKI by directly injuring tubular epithelial cells. This disrupts renal filtration and reabsorption, leading to acute kidney injury through toxic cellular damage, making this a correct cause of intrarenal AKI.

Choice C reason: A bladder tumor causes postrenal AKI by obstructing urine outflow, leading to backpressure on the kidneys. It does not directly damage renal parenchyma, as intrarenal AKI requires, making this choice incorrect for intrarenal causes of kidney injury.

Choice D reason: Dehydration causes prerenal AKI by reducing blood volume and renal perfusion, not directly damaging the renal parenchyma. Intrarenal AKI involves intrinsic kidney damage, so dehydration’s hypoperfusion effect makes this choice incorrect for intrarenal AKI.

Choice E reason: Ureteral obstruction causes postrenal AKI by blocking urine flow, increasing pressure on the kidneys. It does not involve direct parenchymal damage, as required for intrarenal AKI, making this choice incorrect for the specified type of kidney injury.