|MadSci Network: Anatomy|
One cannot say. Food remains in the stomach for a longer or shorter time, according to the nature of the substances ingested, the way they have been prepared and masticated, the motility of the stomach,etc. While the food is in the stomach, it is attacked by saliva, gastric enzymes and by HCl. Gastric juice and stomach movements convert the gastric contents into a semi liquid acidic paste called chyme.The chyme is passed through the pylorus into the duodenum at intervals and in small quantities. In the intestine it comes into contact with the secretions of the pancreas,the intestine, and the liver. Metabolism and detoxication of any toxicants can occur in each and/or all of these processes. Fasting, for any length of time, can be a dangerous activity. Storage fat is the principal source of energy in fasting. Mobilization of storage fat causes a rise in lipemia and liver fat. This increased fat utilization leads to the production of large quantities of specific acids. These acids are accumulated in the blood and excreted in the urine. These acids (ketone bodies) form a condition known as ketosis. Ketosis causes acidosis, ketonuria, increased urinary ammonia, diminished alkali reserves, hyperventilation, and a lowered alveolar CO2 tension.After the fat stores have been depleted, large quatities of protein are burned. Urinary nitrogen rises, and if the subject is not fed he dies. "Human Physiology".B.A.Houssay, McGraw-Hill Book Co. New York, 1951.
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