A patient with a bacterial abscess develops fever. The final common mediator that acts on the hypothalamus to raise the thermoregulatory set point is:

• A Interleukin-1beta acting directly on hypothalamic neurons
• B Tumor necrosis factor acting on the anterior pituitary
• C Prostaglandin E2 synthesized in the hypothalamus ✓
• D Bradykinin acting on hypothalamic B2 receptors

Explanation

TNF, IL-1 and IL-6 reach the circumventricular organs and induce local production of prostaglandin E2, which resets the hypothalamic thermostat upward. This is why cyclooxygenase inhibitors such as aspirin and paracetamol are antipyretics. The cytokines themselves are upstream signals, not the final mediator, so option A fails. Bradykinin mediates pain and vasodilation peripherally and has no established role in the febrile response.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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