digestive system Flashcards
unit 4
what are all the components of the digestive system
buccal cavity, salivary glands, epiglottis, oesophagus, stomach, small intestine, large intestine, liver, rectum, anus, gall bladder, bile duct, pancreatic duct, pancreas
buccal cavity
mouth
salivary glands
produce saliva to help moisten the food and make it easier to swallow
epiglottis
flap of cartilage which covers the opening if the windpipe and prevents chocking
oesophagus
preforms peristales which are muscle contractions that propel the food to our stomach
stomach
breaks food up into chunks, enzymes are released to break the food down into protiens. leaves the stomach as chyme and goes to the small intestine
liver
produces and sends bile to the gall bladder, the bile neutralises the chyme and helps breakdown fats.
gall bladder
secretes bile into the start of the small intestine
bile duct
bile passes here from the gall bladder to the stomach
pancreas
produces digestive juices and transfers bile into the stomach
pancreatic duct
produces another fluid containing enzymes (amylase/lipase) and alkaline salts from the pancreas into the stomach
small intestine
chyme from the stomach moves to the ileum which is part of the small intestine and the ileum is covered in villi that contain blood vessels, nutrients are carried into the blood stream. fats and broken down into fatty acids and proteins are broken down into amino acids.
large intestine
reabsorbs left over fibre, water and waste from the digested food. this is drained and turned into poo
rectum
will expand to release the waste
anus
this is where the bodys waste exits
what is mechanical digestion
chewing food to physically break it down, most important form takes place in the stomach where muscles in the walls of the stomach churn the food and break it down into smaller pieces
what is chemical digestion
proteins, carbs and fats are large nutrients which need chemicals to break them down, they have to be broken down by enzymes which break down the chemical bonds
what are the digestive roles of the liver and the pancreas
-enzymes in the saliva help to breakdown food, the stomach produces hydrochloric acid which continues to help the food to be broken down, the chyme enters the duedoum to become neutralised and alkaline saltes are added from bile which has entered from the liver and pancreatic juices from the pancreas, finally the chyme is broken down in order to be apssed into nutrients so that oit can go into the blood stream.
what is the role of the gall bladder
the gall bladder stores bile which is released when fat is eaten
how are the walls of the small intestine adapted for the absorption of nutrients
villi-large surface area on the walls of the small intestine
large capillaries in each villi so nutrients can be easily absorbed
villi contain one cell thick walls which causes a short diffusion pathway so nutrients can be easily absorbed
what is assimilation
movement of digested nutrients into the body cells to become part of the cells
what are some causes of ibs
triggers: alcohol, caffeine, stress, family history, infection of the large intestine
Intestine walls sensitive to certain foods
what are some symptoms of ibs
abdominal pain and bloating, increased wind, constipation
what are some treatments for ibs
reduce stress, avoid food triggers, probiotics, medication to relax bowel, extreme cases will lead to surgery
