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Monday, December 21, 2009

Week 7 reflection

Digestive Juices

The digestive juices are the secretions of the digestive tract that break down food. They include saliva,gastric juice, pancreatic juice,bile,and intestinal juice.The digestive juices are secreted by different organs, it varies widely in chemical composition, and each play different roles in the digestive process.Each is constantly produced by the body in small amounts, but the presence of food as it passes through the digestive tract causes increased production and secretion.

Where does digestion begin in?

Digestion begins in the mouth, where the mechanical action of the teeth and tongue and the chemical action of saliva begin to break down food. Saliva is produced by the salivary glands in the mouth.Upon being swallowed, food heads to the stomach, where it is bathed in gastric juice, the second of the digestive juices. Gastric juice is a nearly colorless, strongly acidic liquid secreted by the gastric glands. Its active food-dissolving ingredients are the digestive enzymes pepsin and rennin, which break down proteins, and hydrochloric acid. Gastric juice also contains mucus to protect the stomach lining from being dissolved by the acid.

Sunday, December 6, 2009

Week 6 reflection


Digestion is the mechanical and chemical breaking down of food into smaller components, to a form that can be absorbed, for instance, into a blood stream. Digestion is a form of catabolism; a break-down of macro food molecules to smaller ones.
Digestion imammals, food enters the mouth, being chewed by teeth, with chemical processing beginning with chemicals in the saliva from the salivary glands. Then it travels down the esophagus into the stomach, where acid both kills most contaminating microorganisms and begins mechanical break down of some food, and chemical alteration of some. After some time, the results go through the small intestine, through the large intestine, and are excreted during defecation.

Why is digestion important?

When you eat foods—such as bread, meat, and vegetables—they are not in a form that the body can use as nourishment. Food and drink must be changed into smaller molecules of nutrients before they can be absorbed into the blood and carried to cells throughout the body. Digestion is the process by which food and drink are broken down into their smallest parts so the body can use them to build and nourish cells and to provide energy for your activities in daily life.

How is food digested?

Digestion involves mixing food with digestive juices, moving it through the digestive tract, and breaking down large molecules of food into smaller molecules. Digestion begins in the mouth, when you chew and swallow,through the stomach and is completed in the small intestine.

Week 5 reflection

Definitions of digestion:
  1. The process of decomposing organic matter (as in sewage) by bacteria or by chemical action or heat
  2. The organic process by which food is converted into substances that can be absorbed into the body
  3. learning and coming to understand ideas and information; "his appetite for facts was better than his digestion" 
  4. In alchemy, Digestion is a process in which gentle heat is applied to a substance over a period of several weeks.
  5. Digestion is the mechanical and chemical breaking down of food into smaller components, to a form that can be absorbed, for instance, by a blood ...
  6. Digestive - relating to or having the power to cause or promote digestion; "digestive juices"; "a digestive enzyme"; "digestive ferment" 
  7.  The process the body uses to break down food into simple substances for energy, growth and cell repair.
  8. The biochemical decomposition of organic matter, resulting in partial gasification, liquefaction, and mineralization of pollutants.
  9. The process in which digested food is broken down into molecules that are usable by cells.
  10. Process in which food is broken down by the stomach and small intestine and absorbed by the body.
  11. The process of breaking down food into its molecular and chemical components so that these nutrient molecules can cross plasma membranes.
  12. The breaking down of food into forms the body can use.
  13. The process by which larger molecules of food substance are broken down mechanically and chemically into smaller molecules that can be absorbed.
  14. An ulcer refers to a sore on the lining of the stomach or duodenum, which is the beginning of the small intestine.
  15. Either in the presence of oxygen (aerobic) or in an oxygen-depleted atmosphere (anaerobic), digestion is the process in which microbes digest biogenic carbonaceous materials and emit any number of energetic, inert gases and liquids.