Evolution would be the answer you may be looking for.
Answer: "homeostatic (dynamic equilibrium) range"
Homeostasis can be observed through the "homeostatic range (pre-set limits)" of the body's pH, temperature and blood glucose.
Explanation:
Homeostasis is the control of internal environment , physical and chemical conditions maintained by the living systems. A body takes control of its internal environment in spite of external forces interruptions. It can be defined as the body's defensive mechanisms.
Homeostasis is maintained and controlled by the nervous system.
Homeostasis is for optimal functioning of the internal environment such as body pH, body temperature, fluid balance, chemical ions balance (calcium, sodium and potassium) and blood glucose.
Body temperature is normally about 37.5° C (98.6° F).
Salt concentration in body fluids is normally about 0.9%
Blood glucose is normally about 10 mg/ml.
A disturbed (imbalanced body as a result of external forces) body regains its haemostasis balance by
Activating reflexes that fight the disturbance and maintaining behaviours to counteract the disturbance.
Think of blood as a gas/ fuel for the car ( your body). If there is no fuel, there's no movement (dead) so when the fuel tank is damaged the car won't function properly.
So if the heart becomes damaged, or weakened it would start making blood clots and damage the organs that need blood to function properly. The circulatory system wouldn't function properly and because other organs depend on the circulatory system it would cause a chain reaction, affecting other body systems. <span />