The Panini: This is a normal ham, lettuce, tomato and olive oil panini.It’s journey through the digestive system will be recorded here. The panini bread mainly consists of carbohydrates. The ham containprotein. The lettuce contains fiber and small amounts of protein and carbohydratesand the olive oil contains lipids. The mouth: This is the start of the panini’s journey.
Asit passes into the mouth the teeth start crunching it and mixing it withsaliva. The saliva is used to soften the food to make it easier to chew, italso contains amylase which starts breaking down the carbohydrates into thedisaccharide maltose. The teeth chew the food into boli to increase the surfacearea so that chemical reaction takes place quicker. The Oesophagus: The bolus is squeezed quickly down theoesophagus by two antagonistic muscles, a circular muscle and a longitudinalmuscle. This is called peristalsis.
It takes the muscles 1-2 seconds to push the boli to the stomach. The stomach: As the bolus enters the stomach muscles in thestomach contract and relax churning the bolus with gastric acid which consistsof HCl and pepsin the HCl creates the optimum ph for pepsin to work. The pepsinbreaks down the protein into smaller polypeptides.
The newly churned formulaleaves the stomach via a sphincter muscle it is now called chyme. The Duodenum: This is the first part of the small intestine. The chymeis mixed with alkaline fluid to neutralize the mixture. Here the bile, which iscreated in the liver and stored in the gallbladder as well as the pancreaticjuice which is created in the pancreas is mixed in with the chyme. These arethoroughly mixed with the chyme due to the peristalsis This is how the enzymes in this mixture breakdown the food: The rest of the carbohydrates broken down to maltose usingamylase found in the pancreatic juice then broken down to glucose using maltasewhich is released by the walls of the small intestine, lipids are emulsified bybile salts then broken down to glycerol and fatty acids and finally thepolypeptides are broken down to amino acids. This is then passed into the Ileum.
The Ileum: The Ileum is the main region for chemical absorption.The walls are covered with Villi which absorb the nutrients and the broken downproducts into the bloodstream. These Villi increase the surface area to speedup the absorption, to help this the Villi are covered in Micro-Villi. At thispoint the chyme consists mainly of fiber, water and indigestible waste left inthe digestive tract. Large Intestine: As the chyme is pushed into the large intestines it ismixed with bacteria which then produce essential vitamins from the chyme andthe vitamins are then absorbed into the blood stream. The chyme is then slowlypushed through the intestine with peristalsis. The fiber is important here asit gives the chyme bulk so it easier to push. The Colon, Rectum and Anus: The chyme finally enters the colon where mostof the water is reabsorbed into the bloodstream.
It then enters the rectumwhere it is stored as faeces and it stays in the rectum until enough faeceshave been gathered at which point a message is sent to your brain telling youto go to the loo where the faeces are dispelled through the anus. The End