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 contain
protein. The lettuce contains fiber and small amounts of protein and carbohydrates
and the olive oil contains lipids.
The mouth: This is the start of the panini’s journey. As
it passes into the mouth the teeth start crunching it and mixing it with
saliva. The saliva is used to soften the food to make it easier to chew, it
also contains amylase which starts breaking down the carbohydrates into the
disaccharide maltose. The teeth chew the food into boli to increase the surface
area so that chemical reaction takes place quicker.
The Oesophagus: The bolus is squeezed quickly down the
oesophagus by two antagonistic muscles, a circular muscle and a longitudinal
muscle. 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 the
stomach contract and relax churning the bolus with gastric acid which consists
of HCl and pepsin the HCl creates the optimum ph for pepsin to work. The pepsin
breaks down the protein into smaller polypeptides. The newly churned formula
leaves the stomach via a sphincter muscle it is now called chyme.
The Duodenum: This is the first part of the small intestine. The chyme
is mixed with alkaline fluid to neutralize the mixture. Here the bile, which is
created in the liver and stored in the gallbladder as well as the pancreatic
juice which is created in the pancreas is mixed in with the chyme. These are
thoroughly mixed with the chyme due to the peristalsis This is how the enzymes in this mixture break
down the food: The rest of the carbohydrates broken down to maltose using
amylase found in the pancreatic juice then broken down to glucose using maltase
which is released by the walls of the small intestine, lipids are emulsified by
bile salts then broken down to glycerol and fatty acids and finally the
polypeptides 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 down
products into the bloodstream. These Villi increase the surface area to speed
up the absorption, to help this the Villi are covered in Micro-Villi. At this
point the chyme consists mainly of fiber, water and indigestible waste left in
the digestive tract.
Large Intestine: As the chyme is pushed into the large intestines it is
mixed with bacteria which then produce essential vitamins from the chyme and
the vitamins are then absorbed into the blood stream. The chyme is then slowly
pushed through the intestine with peristalsis. The fiber is important here as
it gives the chyme bulk so it easier to push.
The Colon, Rectum and Anus: The chyme finally enters the colon where most
of the water is reabsorbed into the bloodstream. It then enters the rectum
where it is stored as faeces and it stays in the rectum until enough faeces
have been gathered at which point a message is sent to your brain telling you
to go to the loo where the faeces are dispelled through the anus.