Download File

Mouth
The mouth includes teeth and the tongue.
 Teeth cut and grind food.
 The tongue moves food around the mouth to help you chew.
Salivary glands
Salivary glands produce saliva.
 Enzymes in saliva break down starches and salts in food.
 Saliva lubricates food to make it easier to swallow.
Pharnyx (throat)
The pharnyx pushes food into the esophagus.
 Muscles in the pharnyx contract and expand to move food down.
 A flap of cartilage called the epiglottis opens and closes at certain times to keep food
from going down your air passage (trachea)
Esophagus
The esophagus connects the pharynx to the stomach.
 Food travels down this 10-inch-long tube to go to the stomach.
Stomach
The stomach stores and digests food.


Parietal cells in the stomach produce hydrochloric acid. The acid kills harmful bacteria.
Enzymes in the stomach help break down food.
o the enzyme lipase breaks down fats
o the enzyme pepsin breaks down protein
1 to 2 hours later the liquified food is moved towards the small intestine. This movement is
caused by waves of muscle contractions – a process called peristalsis
Liver
The liver has over 250 functions (jobs) in the body! During digestion, it:
 removes nutrients from the bloodstream to make amino acids
 kills bacteria and other foreign threats
 makes alcohol and some other poisons less toxic
 stores minerals (iron, copper) and some vitamins (A, B12, D, E, and K)
 produces bile, which is used by the gallbladder and small intestine
Gallbladder
The gallbladder stores bile and releases it to the small intestine after a meal.
Pancreas
The pancreas produces chemical compounds that neutralize the stomach’s hydrochloric acid.
(If the acid was not neutralized, it would damage the rest of your body.)
The pancreas produces enzymes that break down carbohydrates, lipids, and proteins.
 Lipase enzymes break triglycerides into fatty acids and monoglycerides
 Amylase enzymes breaks down carbohydrates into smaller pieces
 Protease enzymes break down proteins into peptides and amino acids
Small intestine
The small intestine breaks down the final food particles and absorbs nutrients.


Bile (made by the liver) and enzymes (made by the pancreas) break down food particles.
Nutrients are absorbed by tiny, finger-shaped villi in the intestinal wall.
o blood vessels inside the villi carry nutrients to the liver
o fun fact: there are five million villi in the small intestine!
Large intestine
The large intestine solidifies digestive waste and prepares it for export from the body.
Cecum
 The cecum connects the small intestine to the colon.
Colon
 Bacteria that live in your colon break down food components that your body cannot.
o For example, cellulose (a plant fiber) cannot be broken down by human enzymes
o The bacteria break down the cellulose. They use some of the nutrients and give
some of the nutrients to us.
 The colon changes liquified digestive waste into solid waste.
 The solidified waste is moved towards the rectum for export.
Rectum
 The rectum is a passageway between the colon and anus.
 During defecation, feces goes through the rectum and out of the body through the anus.
Your assignment
Create an artistic representation of the digestive system. This can be a poem, song, skit, dance,
model, drawing, or something else. You may work individually, with a partner, or in a group.
Whatever you decide to create, you must:
Use one from each:
1. mouth, salivary glands, pharnyx, esophagus
2. stomach
3. liver, gallbladder, pancreas
4. small intestine
5. large intestine
Include one action for each of the five words above.
Example: The liver stores minerals and vitamins.
Example: The pharnyx pushes food into the esophagus.
Note: You do not have to say or write the action (although you may if you wish), but you must
express that action somehow and be able to explain your presentation of it.