When food intake ceases, the body enters the<unk>  response. Initially, the body's glycogen stores are used up in about 24 hours. The level of insulin in circulation is low and the level of glucagon is very high. The main means of energy production is lipolysis. Gluconeogenesis converts glycerol into glucose and the Cori cycle converts lactate into usable glucose.  Two systems of energy enter the gluconeogenesis: proteolysis provides alanine and lactate produced from pyruvate, while acetyl CoA produces dissolved nutrients (Ketone bodies), which can be detected in urine and are used by the brain as a source of energy.
In terms of insulin resistance,<unk>  conditions make more glucose available to the brain.
Starvation pathophysiology
Sepsis pathophysiology
Zollinger-Ellison syndrome pathophysiology
Hamman-Rich syndrome pathophysiology
Hyperthermia pathophysiology
Heat stroke pathophysiology
Volvulus pathophysiology
Acute diarrhea pathophysiology