Question

The pancreas secretes many enzymes, collectively referred to as ______ that are deposited into the first section of the small intestines as the creamy stomach fluid called ______ enters. The fluid is too acidic for pancreatic enzymes to function, so a buffering ion called ______ is secreted into area to bring the pH back up to about 7.8 to 8.2. In addition to pancreatic enzymes, the gall bladder secretes ______ through its own duct as well. This mixture aids in the digestion of lipids by breaking large fat drops into smaller droplets (increasing surface area for digestion) and by forming aggregates called ______ that alter the arrangement of the fat molecules to make them more easily digestible. Glands in this section of intestines also produce enzymes that aid in the chemical digestion of food. Water is added as well, creating a slurry of nutrients. In the next two sections of intestines, muscle contractions called ______ move the food forward and backward instead of just propelling it through the tract.

Answer 1

The process of food ingestion, digestion, absorption and excretion, is a pretty long and complex one, which requires not just physical and mechanical actions by the body, particularly the digestive tract, but also the action of diverse chemicals, best known as enzymes, that will ensure that nutrients in food can be taken from the food and used properly by the cells of the body. Starting with simple activation of the nervous system by smell, touch, sight, or simple thought, and ending with the actual excretion, digestion is a pretty interesting dance.

The answers, then, to the questions, would be as follows:

1. Pancreatic juices. These are vital for the digestion and absorption mainly of fats and sugars. Proteins are mostly the responsibility of stomach enzymes, though the pancreatic juices finalize what the stomach enzymes started.

2. The creamy content that leaves the stomach and enters the duodenum, is called the chyme. This is simply the fluid way in which the once solid foods, and liquid foods, travel down the system so that nutrients can be extracted.

3. Because the chyme is coming from the stomach, where large amounts of acid have been added to work on proteins, most pancreatic enzymes would become inactive. Therefore, the pancreas, especially the epithelial cells of it, secrete bicarbonate ions to bring the pH of the chyme down. Then can the different lipases, amylases, and other pancreatic enzymes, work.

4. The gallbladder functions mainly as a reservoir of bile, the substance created by the liver and which contains salts. However, it also adds to the bile produced by the liver by hyper-concentrating what is stored inside by removing water and electrolytes from it. This is why liver bile and gallbladder bile are not exactly the same. When lipid-rich food enters the system, cholesystokinin, CCK, is released by the duodenum and jejunum and thus the gallbladder responds by emptying its contents through the common bile duct.

5. The name of the aggregates are mycelles and these allow the pancreatic lipases and other enzymes to work on long-chain fat molecules.

6. The name of the motion that takes place in the small intestine, and which pushes the chyme back and forth, is called the segmental contractions and this allows the chyme to come into contact with the microvilli, which will be th ones taken up the necessary nutrients from the digested foods.