1. Digestive System
In Class Notes:

2. Function (29.1)
The digestion system breaks down foods, provides nutrients, and helps eliminate the waste.
Four Steps:
1.Ingestion: eating
2.Digestion: breaking down food
3.Absorption: certain cells absorb small molecules
4.Elimination: undigested material passes out of the body
Mechanical Digestion:
Ex: Chewing
Chemical Digestion:
Ex: Acids and enzymes in your stomach

3. Organs Involved: (29.2)
Mouth: mechanical digestion, smashes food into smaller pieces for swallowing, creates greater surface area.
Pharynx: (upper portion of the throat) junction of the alimentary canal and the passageway by which air enters the lungs.
Esophagus: muscular tube connecting pharynx to the stomach. Pushes food down by contracting through peristalsis.
Stomach: elastic muscular sac. Gastric juices secreted by glands in the stomach lining. Contracts and uses gastric juices to kill bacteria and break apart the cells in food.

4. Organs involved (cont.)
Small Intestine: Long and narrow, digestion is completed; most absorption takes place. Peristalsis moves chyme produced by the stomach. First section: duodenum. Villi breaks down food further and kills bacteria.
Liver: Bile is produced to prepare fats for digestion and stored in the gallbladder.
Pancreas: produces and secretes pancreatic juice into small intestine. Neutralizes chyme.
Large Intestine: (colon) Very end of digestive process. Absorbs water and digestive juices left over from the process. Feces become solid due to water being removed; moves through the large intestine and is removed generally taking from hours.

5. Sequence of digestion:
Enters mouth (mechanical digestion starts)
Esophagus pushes food to stomach
Stomach uses acid to breakdown food
Food leaves the stomach as chyme to the small intestine
Before long, the liver and gallbladder contribute bile
Nutrients from the food are collected in the villi while traveling in the small intestine
Villi have blood vessels which is cleaned in kidneys
Undigested material flows through the large intestine
The feces is ejected by the rectum through the anus

6. Diagram:
Here are all the parts:

7. Parts you should know:

8. Nutrition: (29.3)

9. Serving Suggestions
Fruits- one banana,six strawberries, two plums, fifteen grapes, one apple, one peach, one half cup of orange or other fruit juice
Vegetables- five broccoli florets, ten baby carrots, one roma tomato, 3/4 cup tomato juice, half of a baked sweet potato, one ear of corn, four slices of an onion
Dairy- 1 cup of fat-free or low-fat milk, 1 cup of fat-free or low-fat yogurt, 1 ounce of low-fat cheese
Grain- a slice of bread (35 g), ½ pita bread (35 g) or 125 mL (½ cup) of - cooked pasta, rice or couscous
Meat- 2 to 3 ounces of cooked lean meat, poultry or fish

10. Vocabulary: Bolus- A clump of food that leaves mouth to stomach
Peristalsis- Muscle contractions that move food
Constipation- When you cant poop
Diarrhea- When you cant stop pooping
Nutrition- Healthy amount of food
Ingestion- Eating
Absorption- absorbing vitamins from food
Elimination- pooping out your food
Feces- poop in the large intestine
Chyme- Stomach acid and food
Saliva- liquid in mouth to break up food

11. Nutritional Disorders (29.4)
Malnutrition: A diet lacking one or more essential nutrients
Under nutrition: Lack nutrients and calories in a diet.
Obesity: The condition of being seriously overweight can increase risk of heart disease, diabetes, stroke, and asthma. About 60% of Americans suffer from Obesity. About 13% are children/teens.
Eating Disorders: mental condition that affects a persons diet. Ex: Are Anorexia and Bulimia.

12. Digestive System Disorders:
A. Gluten Allergy- “Celiac Disease” Scars lining of the small intestine.
B. Anorexia- Eating disorder. Self-starvation.
C. Ulcers- Open painful wound in the stomach. D:
D. Constipation- Colon absorbs too much water, poor diet can be another factor.
E. Cronn’s Disease- Genetic. Inflamed GI track.
F. Heartburn- Stomach acid gets into the esophagus. Also called acid reflux.
G. IBS- “Irritable Bowel Syndrome” Genetic.
.::That’s all Folks::.