| Term | Definition |
|---|
| small intestine | Approx. 2.5cm wide + 7m long. Arranged in series of orderly loops. Divided into 3 parts. |
| duodenum | first 25-30cm, most chemical digestion takes place here. |
| jejunum | 3m long, absorption into the circulatory and lymph system |
| ilium | 3m long, end of small intestine |
| mesentary | Contains nerves, blood vessels, to transport materials to and from intestine |
| muscle layers | circular and longitudinal, move material by peristalsis |
| mucosa | folds, projecting from folds are small finger like villi. increase surface area |
| lacteals | Found in center of each micro villi, provides products of fat digestion |
| liver | performs more than 500 functions, production of bile, stores glycogen etc. |
| gallbladder | Stores bile until needed |
| pancreas | produces sodium bicarbonate, and many digestive enzymes. |
| large intestine | shorter than small intestine, but twice the diameter. main use is reabsorption of water and production of vitamin B and K. has three sections |
| ascending colon | rises up on the right of the abdomen |
| transverse colon | crosses middle of abdomen |
| descending colon | goes down left side of abdomen, terminates at rectum. |
| fibre | in the form of cellulose is neccesary for a healthy colon. |
| mouth | Mechanical and chemical digestion begins here. Physical breakdown of food by teeth |
| gastrointestinal tract | a one-way digestive tract that makes possible the seperation of digested and undigested food. |
| tongue | forms a bolus (ball) out of the chewed food + pushes it to the back of the mouth into the pharynx |
| esophagus | inner layer called the mucosa, allows for smooth movement of food. Bolus activates stretch receptors which in turn activate smooth muscles that start peristalsis |
| peristalsis | Rhythmic, wavelike contractions |
| stomach | J-shaped - mostly involved in digestion but small amount of absorption |
| mucosa | is composed of three types of cells |
| mucous | protects stomach lining |
| enzymes | protein substances that speed up chemical reactions. |
| hydrochloric acid | assits in breakdown of fibrous tissue and destroys foreign organisms |
| pepsin | enzyme that breaks down proteins |
| mesentary | Outside layer - holds organ in place to help prevent damage |
| cardiac sphinctor | Regulates movement of food into stomach and helps to prevent it from going back into the esophagus. |
| pyloric sphinctor | located between stomach and small intestine, controls the movement of partially, digested food. |
| ingestion | the process of taking food into the body through the mouth (as by eating) |
| digestion | The breakdown of complex organic molecules into smaller components by physical and chemical means |
| absorption | the taking up of digested molecules into the cells of the digestive tract |
| egestion | the removal of waste food materials from the body |
Combine with other sets
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