03-15-2009, 10:21 PM
During starvation, there would be a drop in the blood glucose concentration therefore the tissue cells would want to obtain glucose from the blood. Due to the lack of blood glucose in bloodstream, this stimulates the islets of Langerhans in the pancreas to secrete glucagon so as to convert the stored glycogen in liver to glucose, which then oxidise in tissue respiration to release energy to keep up cell activities to keep the body going. the basic units of proteins, amino acids, are already converted to protoplasm for growth and repair of worn-out parts and the synthesis for hormones and enzymes, therefore, there is a decrease in the liver. as for the lipids, usually if the blood glucose concentration are between 70 to 90mg/100cm3 of blood, it is considered normal, and the fats would be stored in adipose tissues beneath skin and around heart and liver and use for the formation of protoplasm in nuclear and plasma membrane. However, in crisis like starvation, the fats are oxidised in tissue respiration to provide energy for cell activities.For example, in an anorexic, their bilirubin levels(bile pigments) would drop as there isn't enough iron in the body to break down the heme groups in the haemoglobin of worn out RBC. They may also go into shock, as the levels of essential products are lacking. for example, in an anorexic, they would constantly monitor the level of substance produced and excreted in the liver and kidneys. usually, anorexic would die of organ failure, like the liver, since it has more than 500 functions.Therefore, in starvation alone, the organs would slowly"die"hence we cannot live without food for a few days.My information are rather simplified and one-sided account since my knowledge is too limited and narrow. You could check out the net.
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