who discovered the working of stomach and how
William Beaumont By August 1825, Beaumont had been relocated to Fort Niagara in New York, and Alexis St. Martin had come with him. Beaumont recognized that he had in St. Martin an unusual opportunity to observe digestive processes. Dr. Beaumont began to perform experiments on digestion using the stomach of St. Martin. Most of the experiments were conducted by tying a piece of food to a string and inserting it through the hole into St. Martin's stomach. Every few hours, Beaumont would remove the food and observe how well it had been digested. Beaumont also extracted a sample of gastric acid from St. Martin's stomach for analysis. In September, Alexis St. Martin ran away from Dr. Beaumont and moved to Canada, leaving Beaumont to concentrate on his duties as an army surgeon but Dr. Beaumont had him caught to continue to exhibit him. Beaumont also used samples of stomach acid taken out of St. Martin to "digest" bits of food in cups. This led to the important discovery that the stomach acid, and not solely the mashing, pounding and squeezing of the stomach, digests the food into nutrients the stomach can use; in other words, digestion was primarily a chemical process and not a mechanical one.[8]
Gizzard Birds swallow food and store it in their crop if necessary. Then the food passes into their glandular stomach, also called the proventriculus, which is also sometimes referred to as the true stomach. This is the secretory part of the stomach. Then the food passes into the gizzard (also known as the muscular stomach or ventriculus). The gizzard can grind the food with previously swallowed stones and pass it back to the true stomach, and vice versa. In layman's terms, the gizzard 'chews' the food for the bird as it does not have teeth to chew food the way humans do. Bird gizzards are lined with a tough layer made of the carbohydrate-protein complex koilin, to protect the muscles in the gizzard.