THE DIGESTIVE SYSTEM Flashcards
what is the definition of digestion?
the chemical and mechanical breakdown of food. it converts large insoluble molecules into small soluble molecules which can be absorbed into the bloodstream.
how is digestion sped up?
by enzymes
what is the function of the mouth?
the mechanical breakdown of food.
what is the function of the salivary gland?
produces saliva which contains the enzyme amylase.
what is the function of the oesophagus?
tube that connects the mouth to the stomach. muscular contractions for swallowing.
what is the function of the liver?
produces bile
what is the function of the gall bladder?
stores bile from the liver.
what is the function of the stomach?
contains the enzyme pepsin, and hydrochloric acid to kill bacteria.
what is the function of the pancreas?
produces amylase, lipase and protease enzymes and releases them into the duodenum.
what is the function of the ileum?
where the absorption of food molecules into the blood stream takes place.
what is the function of the duodenum?
where the food comes into contact with the bile.
what is the function of the colon?
water from waste food is absorbed here.
what is the function of the rectum?
where feaces is stored.
what is the function of the aenus?
feaces leaves the body here.
what is peristalsis?
a wave of muscular contractions moves along the gut. circular muscles contract and longitudinal muscles relax to narrow the tube and to push the food along.
how is the ileum adapted to the absorption of food?
villi have large surface area and a good blood supply to absorb nutrients.
what is ingestion?
the consumption of food.
what is chemical digestion?
the involvement of enzymes to breakdown food.
what is physical digestion?
when the food is physically broken down by the teeth in the mouth.
what is absorption?
taking in nutrients into the blood stream.
what is assimilation?
soluble food molecules are absorbed from the blood into the cells of tissues and are used to build new parts of cells.
what is egestion?
getting rid of waste products.
what is dietary fibre?
found in fruit and vegetables, helps the gut to contract. prevents constipation and colon cancer.
what are digestive enzymes?
a bio catalyst. work on living things to speed up chemical reactions, they are made of protein. digestive enzymes break up large insoluble molecules into smaller soluble molecules which can then be absorbed.
