The Digestive System Flashcards
what is the function of the appendix?
part of the large intestine - no known use.
what is the function of the liver?
this organ produces bile which is used to break down large fat globules into smaller droplets.
what is the function of the stomach?
this organ contains hydrochloric acid to kill bacteria and also contains the enzyme pepsin to digest protein.
what is the function of the mouth?
food broken down into small pieces by teeth - increases surface area.
mixed with saliva that contains amylase which digests starch.
what is the function of the oesophagus?
carries food to the stomach by waves of muscle contractions called peristalsis.
what is the duodenum?
the first part of the small intestine
what is the function of the duodenum?
In the duodenum enzymes from the pancreas mix with the food. These enzymes include, amylase, protease and lipase to digest starch, protein and lipids.
what is the alimentary canal?
the gut from the mouth to the anus.
what us the ileum?
the second part of the small intestine.
what is the function of the ileum?
the walls of the ileum make enzymes - maltase, protease and lipase.
Products of digestion (small soluble food molecules) are absorbed across the wall of the ileum into the blood.
what makes up the large intestine?
the colon and the rectum
what is the function of the colon?
colon absorbs water from the undigested food to produce faeces.
what is the function of the rectum?
at the end of the colon - this is where faeces is compacted and pushed out of the anus by egestion.
where is bile made?
the liver
where is bile stored?
gall bladder
what is the function of bile?
Bile always emulsifies fats- breaks them into smaller droplets, with a greater surface area. This speeds up digestion of lipids by lipase.
where does bile move to?
bile moves down the bile duct into the duodenum
why is bile alkaline?
Bile is alkaline so it neutralises the acid coming from the stomach.
how does the length (5mm) of the ileum help absorption?
this gives plenty of time for digestion to be completed, and for digested food to be absorbed as it passes through.
how does the cells in each villus help absorption in the ileum?
Each villus is covered in cells which have smaller projections on them called microvilli. This gives the inner of the small intestine a very large surface area. The larger the surface area, the faster the food can be absorbed.
how does the blood capillaries in the villi help absorption?
digested food passes into the blood to be taken to the liver and then round the body.
how do lacteals in the villi help absorption?
Villi contain lacteals which are part of the lymphatic system. Fats are absorbed into the lacteals.
how does the thickness of the walls of the villi help absorption?
The walls of the villi are only 1 cell thick so the digested food can easily cross the wall to reach the blood capillaries and lacteals.
