THE DIGESTIVE SYSTEM

THE DIGESTIVE SYSTEM1DIGESTIVE SYSTEM ASSIGNMENTIn a group of 3 or 4 you are to create an information handout of a particular structure of the digestive system and present their information to the class.Your handout must include: description and picture of the structure, function of structure, and how the structure works to achieve its contribution to digestion. Your choices are: the oral cavity esophagous stomach small intestine large intestine salivary glands liver and gallbladder pancreas rectum & anusEach group must have a different topic (NO OVERLAP). Handouts must be complete by the end of the period. Copy and paste into my hand-in file. Presentations will be done on Wednesday.

2DIGESTIVE SYSTEM FUN FACTSWe each eat about 250 kg (1/4 ton) of food per year. False: we eat about 500 kg (1/2 ton) of food each yearWe each produce 1.7 litres of saliva every year.TrueMuscles contract in waves to move the food down the oesophagus. This means that food would get to a persons stomach even if they were standing on their head.True

3An adult stomach can hold approximately 1.5 litres of material.TrueThe digestive system of an adult human is about 5 m long.False: its about 8 m longEvery day 11.5 litres of digested food, liquids and digestive juices flow through the digestive system, but only 100 mLs is lost in faeces (poo)True

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Salivary glandseosophagustracheastomachpancreasSmall intestineLarge intestineRectum/anusMouth/teethGall bladderliverduodenumappendix5Digestion presentations6Handouts: the digestive organs : distinguishing b/w mechanical and chemical digestion Article: the Bacteria in my gut

7DIGESTIVE SYSTEM DISORDERS/ DIAGNOSIS TECHNIQUESFor this group (2-3 people) assignment you are to prepare a summary of the information you gather. The summary should include the following:If you are doing a disorder: include cause, symptoms, complications, diagnosis and treatment,If you are doing diagnosis techniques: include a description of the technique and any complications.

DISORDERDIAGNOSIS TECHNIQUESheartburnUpper GI seriesGall stonesUpper endoscopyLactose intoleranceFlexible sigmoidoscopyCirrhosis of the liverLower GI seriesInflammatory bowel diseasecolonoscopyulcersEndoscopic retrograde cholangiopancreatography (ERCP)Diverticular diseaseIrritable bowel syndrome8DIGESTIVE ENZYMESBiological catalystsProteinsBreakdown nutrients through process of hydrolysis9Human enzymes of DigestionENZYME GROUPAMYLASEPROTEASELIPASEExample of this enzymeSourceSubstrateProductsOptimum pHSalivary amylasepepsinPancreatic lipasestarchWall of stomachpancreasSalivary glandsproteinsTriglycerides (fats or oils/maltoseSmall polypeptidesFatty acids and glycerolpH 7pH 1.5pH 710

DIGESTION OFCARBOHYDRATES11Insert pic of digestion of fats

THE DIGESTION OF FATS12Insert pic of digestion of proteins

13Lab: how enzymes are affected by temperature?14An example of HomeostasisREGULATING BLOOD SUGAR15HOMEOSTASIS: the process by which an organism maintains a constant internal environmentIncludes the control of constant temperature, blood pressure and blood sugar levels16HOW DOES HOMEOSTASIS OCCUR?All of the bodys organ systems are involved in this work. They use a negative feedback system.i.e. The body has a set of conditions under which it operates. If one of these conditions is broken, receptors send signals to other organs in the body.When organs receive these signals, they respond in such a way that counteracts the change to the system.17BLOOD SUGAR CONTROL AS AN EXAMPLE OF HOMEOSTASISPancreas is the primary organ involved in regulating blood sugar. Cells in the Islets of Langerhans, alpha and beta cells, monitor and control blood sugar levels.The set level of blood sugar in the body is 4-6 mmol/L

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19After you eat, blood sugar levels rise. Receptors signal the pancreas to release insulin (via beta cells) into the blood stream.When receptor cells sense a return to the set level of blood sugar, they signal the pancreas to stop releasing insulin, and stimulate storage of extra glucose as glycogen in the liverWhen blood sugar levels bet below set point, alpha cells release a hormone classed glucagon that induces the release of glucose from the liver by changing glycogen back into glucose20Diabetes clip?Tw: p 274 # 5, 6, 7

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