1. A Tour of the Digestive System

2. A note about the small intestine…
Most of digestion and absorption of nutrients occur here
How long is your small intestine?
About 6m (20 feet!)

3. Small intestine zones 3 Zones: Liquids enter duodenum from:
Duodenum (first 25 cm)
Jejenum
Ilium
Liquids enter duodenum from:
1. Liver
2. Pancreas
3. Gall Bladder

4. How it all fits together…

5. You can’t LIVE without it! (The liver)
produces bile (up to 1.5L per day!), stored in the Gall Bladder
a thick green liquid
breaks fat into droplets
What kind of digestion does bile perform?
Mechanical or Chemical?

6. Gall bladder problems…
Gall stones
usually from hardened cholesterol pieces

7. Surgical removal is sometimes necessary…
Q: How can you prevent gall stones from forming? A:
Q: If you didn’t have a gall bladder, how would your diet need to change?

9. What else does the liver do?
Keeps blood concentrations (of nutrients, hormones, glucose etc.) constant
Changing nutrients (e.g. carbohydrates into fats, amino acids into carbohydrates and fats).
Removes toxins from the blood

10. Destroys old red blood cells.
Makes urea (from the breakdown of amino acids)
Makes proteins in the blood
Makes cholesterol
Stores iron and vitamins

11. The Pancreas Connected to the duodenum by a duct Pancreatic juice has:
Sodium bicarbonate
 neutralizes the acidic chyme
Enzymes to further break down food
Pancreatic amylase
Starch  maltose
Trypsin
Protein  peptides
Lipase
Fats  glycerol and 3 fatty acids

12. Fats break down to molecular level!
Lipase
Fatty Acid
Glycerol
Fatty Acid
Glycerol
Fatty Acid
Fatty Acid
Fatty Acid
Fatty Acid
Fatty Acids
and Glycerol
Fat

13. More Important pancreatic functions
Regulation of blood sugar!
How long do you typically go without eating in 24 hours?
But your cells need a steady supply of blood glucose to function… not too much, not too little.
How do you manage this?

14. Puzzle Time! Blood sugar rises to normal (90mg/100mL)
Blood sugar falls to normal (90mg/100mL)
Insulin is released from the beta cells of the pancreas
Glucagon is released from the alpha cells of the pancreas
Cells intake of glucose is enhanced
Glycogen from the liver is broken down and released into the blood
You eat a meal and blood sugar rises above normal
You have not eaten for several hours and blood sugar lowers below normal
The liver stores some of the glucose as glycogen
Use the puzzle pieces to create the story of blood glucose regulation
Hint: This story is not a linear one!

15. Key points: When you eat, your blood glucose level rises
Between meals, your blood glucose is used up and levels fall
Your pancreas releases two hormones into the blood: Insulin and Glucagon
Insulin makes cells permeable to glucose
Insulin sticks glucose molecules together to be stored in the liver as glycogen
Glucagon breaks down glycogen (releasing glucose)
Insulin
Glucagon

18. What if you didn’t have insulin?
Diabetes mellitus
A few early symptoms:
Increased thirst
Large volume of dilute urine (Sugar present)
Unexplained weight loss
Increased fatigue
Blurry vision (Type II)
Cuts that are slow to heal (Type II)

19. Diabetes isn’t so sweet…
Some secondary and long-term effects of untreated diabetes:
Loss of vision
Skin lesions (sores)
Damage to gums
Loss of limbs (amputation could be necessary)
Chest pains / increased chance of heart failure
Kidney disease

20. (usually juvenile onset)
Type I diabetes
(usually juvenile onset)
Autoimmune disorder
The beta cells of the pancreas are destroyed
Must be controlled via regular insulin injections

21. Type II Diabetes (usually adult onset)
Less insulin or it does not work as well
Often controlled by diet and exercise
Some people take drugs to increase sensitivity to insulin
Blood sugar monitoring
is essential