Which term corresponds to loss of internal stability?

• A. Homeostatic Failure
• B. Shock Index
• C. Critical Perfusion
• D. Cellular Death

Answer: (A)

Maintaining stable internal conditions is called homeostasis, kept by feedback systems that regulate temperature, pH, fluid balance, and energy supplies. When these regulatory mechanisms fail or are overwhelmed, the body's internal environment can no longer stay within the narrow ranges needed for proper function—that situation is homeostatic failure. The other options point to different ideas: a Shock Index is a calculated measure used to assess the risk of shock, not the loss of regulatory stability itself; Critical Perfusion isn’t a standard term for this concept; Cellular Death describes end-stage cell loss, which can result from severe disruption but doesn’t define the loss of internal stability itself.