1. THE DIGESTIVE SYSTEM

2. DIGESTIVE SYSTEM ASSIGNMENT
In 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 & anus Each 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.

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

4. An adult stomach can hold approximately 1.5 litres of material.
True
The digestive system of an adult human is about 5 m long.
False: its about 8 m long
Every 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)

5. Salivary glands
Mouth/teeth
eosophagus
trachea
Gall bladder
stomach
liver
pancreas
duodenum
Small intestine
Large intestine
appendix
Rectum/anus

6. Digestion presentations

7. Handouts: the digestive organs
: distinguishing b/w mechanical and chemical digestion
Article: the Bacteria in my gut

8. DIGESTIVE SYSTEM DISORDERS/ DIAGNOSIS TECHNIQUES
For 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.
DISORDER
DIAGNOSIS TECHNIQUES
heartburn
Upper GI series
Gall stones
Upper endoscopy
Lactose intolerance
Flexible sigmoidoscopy
Cirrhosis of the liver
Lower GI series
Inflammatory bowel disease
colonoscopy
ulcers
Endoscopic retrograde cholangiopancreatography (ERCP)
Diverticular disease
Irritable bowel syndrome

9. DIGESTIVE ENZYMES Biological catalysts Proteins
Breakdown nutrients through process of hydrolysis

10. Human enzymes of Digestion
ENZYME GROUP
AMYLASE
PROTEASE
LIPASE
Example of this enzyme
Source
Substrate
Products
Optimum pH
Salivary amylase
Pancreatic lipase
pepsin
Salivary glands
Wall of stomach
pancreas
starch
proteins
Triglycerides (fats or oils/
maltose
Small polypeptides
Fatty acids and glycerol
pH 7
pH 1.5
pH 7

11. DIGESTION OFCARBOHYDRATES

12. Insert pic of digestion of fats
THE DIGESTION OF FATS
Insert pic of digestion of fats

13. Insert pic of digestion of proteins

14. Lab: how enzymes are affected by temperature?

15. REGULATING BLOOD SUGAR
An example of Homeostasis

16. HOMEOSTASIS: the process by which an organism maintains a constant internal environment
Includes the control of constant temperature, blood pressure and blood sugar levels

17. HOW DOES HOMEOSTASIS OCCUR?
All of the body’s 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.

18. BLOOD SUGAR CONTROL AS AN EXAMPLE OF HOMEOSTASIS
Pancreas 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

20. After you eat, blood sugar levels rise
After 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 liver
When 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 glucose

21. Diabetes clip?
Tw: p 274 # 5, 6, 7