1. Chapter 12
Digestion

2. The Start of Digestion The Mouth  Food enters here
The Teeth  mechanically breaks down food
The Tongue  Chemically recognizes food. Moves food around the mouth. Assists in swallowing
Salivary Glands  Releases Saliva into the mouth. Saliva starts chemical breakdown and moistens food for swallowing.

3. The Pharynx  The area in the very back of the mouth that receives air from the nasal cavities (air from the nose) and food from the mouth.
Esophagus  The food tube. The tube that goes from the mouth to the stomach. Many muscles surround this tube to help swallow. When muscles work to swallow its called Peristalsis
Trachea  Tube that goes down to the lungs to breath. This has cartridge rings so it is always open.
Epiglottis  covers the Trachea when swallowing so food does not go down into the lungs.

4. Nasal Cavity
Pharynx
Teeth
Mouth Cavity

5. During swallowing the Trachea moves up and forces the Epiglottis to close over the trachea’s opening

6. Swallowing
Step 1: food is chewed in the mouth. Saliva is added for lubrication. Saliva also contains the digestive enzyme Salivary amylase. This enzyme breaks down starches into disaccharides like maltose
Step 2: Food is turned into a Bolus ( a ball of food) and pushed back of mouth by tongue.
Step 3: Muscles move the bolus down the esophagus. This is called peristalsis. The trachea moves up and the epiglottis closes access to the trachea. A muscle in the pharynx closes access to the nasal cavity

7. Nasal Cavity
Pharynx
Epiglottis
Trachea
Esophagus

8. Bolus
Trachea

9. Into the Stomach
The bolus moves down the esophagus and into the stomach.
The cardiac sphincter prevents the food from going from the stomach back up the esophagus.
A sphincter is a muscle that goes around a tube to act as a valve.
The cardiac sphincter is located at the joining of the stomach and the esophagus

10. Gastric Juice Contains:
The stomach has many gastric glands the release gastric juices into the stomach
Gastric Juice Contains:
Pepsin  enzyme breaks proteins to peptides
HCl acid  the acid kills some bacteria, activates pepsin, and breaks up food (but does not digest)
Mucus  slime that covers your stomach wall to protect it against the acid
Muscles around the stomach help mix the food with the gastric juices

11. a
Cardiac Sphincter

12. Into the Small Intestine
After the stomach the pyloric sphincter opens and lets Chyme pass on into the small intestine
The first part of the small intestine is called the duodenum
The duodenum has ducts that enter the duodenum that release many different chemicals

13. Duodenum releases
Bile  comes from liver. Bile is often stored in the Gall Bladder Emulsifies fat.
Pancreatic Juices
Juices from the organ called the pancreas
Sodium bicarbonate  NaHCO3 turns the acidic chyme basic
Pancreatic amylase  breaks down starch into disaccharides. Enzyme.
Trypsin  breaks down protein into peptides. Enzyme
Lipase  breaks down fat. Enzyme
Nuclease  breaks down nucleic acid into nucleotides

15. The small intestine is designed to absorb nutrients.
It has a huge surface area. This is because the inside of the small intestine has finger-like projections called villi. Each villi has finger-like projections called microvilli
The small intestine has a thin layer of mucus over it. Under the mucus are the villi and microvilli. Sugars and amino acids pass through the mucus and get moved into the blood vessels.

16. Enzymes of the Small Intestine
The small intestine has many enzymes that work there to help let materials pass through the wall of the small intestine
Maltase  digests maltose into glucose
Peptidase  digests peptides into amino acids
Nucleosidases  digests nucleotides into bases, sugar, and phosphate

17. Amino acids, sugars, and components of nucleotides, move into the blood by going through the microvilli
The parts of Fat (glycerol and fatty acids ) get moved into the Lacteal.
The lacteal is part of the lymphatic system.

20. Moving into the Large Intestine
The Large Intestine is shorter in length but wider in diameter
Made up of several parts
Ascending colon – part of colon that goes up
Transverse colon – part of colon that goes along side
Descending colon – part of colon that goes down
Cecum – attached to ascending colon. Goes nowhere
Appendix – attached to cecum. Can get infected.
Rectum – where all the feces is stored. End of colon.
Anus – the muscular opening to expel feces.

21. Transverse Colon
Ascending
Colon
Descending
Colon
Cecum
Rectum
Appendix
Anus

22. What happens in the Large Intestine
The large intestine is full of bacteria. A lot the bacteria are anaerobic bacteria.
Anaerobic bacteria  bacteria that do not use oxygen. Bacteria that will die in the presence of oxygen.
These bacteria break down indigestible materials. They also produce some vitamins that are then absorbed by the large intestine wall.
The large intestine absorbs water out of the waste

23. Identify all the parts

24. Review Salivary Glands Stomach Pancreas
Salivary amylase, moistens food
Stomach
Gastric Juices: Pepsin, HCl, Mucus
Pancreas
Pancreatic Juices: NaHCO3, Trypsin, Lipase
Insulin hormone is secreted into the blood
This hormone tells cells in the body to take up glucose
This hormone is released after eating when there is high glucose levels in the blood

25. Pancreas Blood glucose levels are high  releases Insulin
Insulin causes cells to take up glucose
Blood glucose levels are low  releases Glucagon
Tells body to break down glycogen into glucose. Glycogen is found in the liver
Tells body to break down fat into glycerol and fatty acids.

26. Liver Makes Bile Removes any poisons from the blood
Stores Iron and many vitamins
Stores glycogen. This can be made into glucose
Regulates blood cholesterol levels
Produces Urea:
2NH3 + CO2  H2N-C-NH2 + H2O =O

27. Optimal pH for the Enzyme
Location pH
Salivary Amylase
Mouth. Salivary Gland
Neutral
Pancreatic Amylase
Duodenum. Pancreas
Basic
Pepsin
Stomach
Acidic
Trypsin
Pancreas. Duodenum
Peptidase
Small Intestine
Nuclease
Nucleosidase
Lipase
Pancreas, Duodenum

28. SOURCE ENZYME FOOD PRODUCT MOUTH (salivary glands) Salivary amylase
Polysaccharides
Maltose
STOMACH
Pepsin
Proteins
Peptides
PANCREAS
Pancreatic amylase Trypsin
Lipase
Polysaccharides Proteins
Fats
Maltose Peptides
Fatty acids and glycerol
SMALL INTESTINE
Maltase Peptidases
Glucose Amino acids

29. FOOD TYPE ENZYME SOURCE PRODUCTS CARBOHYDRATES
Salivary amylase Pancreatic amylase
Maltase
Salivary glands Pancreas
Small intestine
Maltose Maltose
Glucose
PROTEINS
Pepsin Trypsin
Peptidases
Stomach mucosa Pancreas
Intestinal mucosa
Peptides Peptides
Amino acids
FATS
Lipase
Pancreas
Fatty acids and glycerol

30. Name the Enzyme Involved
Polysaccharides  Maltose  Glucose
Proteins  Peptides  Amino Acids
Fats  Glycerol + Fatty Acids
Salivary amylase
Pancreatic Amylase
Maltase
Name the Enzyme Involved
Pepsin
Trypsin
Peptidase
Lipase

31. Remember to Drink lots of water