What physiological response is triggered by systemic inflammatory mediators in septic shock?

• A. Vasoconstriction
• B. Vasodilation
• C. Hypertension
• D. Increased heart rate

Answer: (B)

In septic shock, systemic inflammatory mediators, such as cytokines, promote vasodilation, which is a key feature of the body's response to infection and inflammation. This vasodilation results from the release of substances like nitric oxide and prostaglandins, which relax the smooth muscles in blood vessels, leading to their widening.

This response helps to increase blood flow to vital organs in an effort to deliver necessary nutrients and oxygen as the body attempts to combat the infection. However, the accompanying reduction in systemic vascular resistance can cause a drop in blood pressure, leading to further complications such as organ dysfunction.

In contrast, vasoconstriction, hypertension, or an isolated increase in heart rate do not reflect the primary physiological state described in septic shock, where the predominant response is one of widespread vasodilation, leading to hypotension and potential organ failure.