Transcript Digestive System

• Chemical and mechanical
breakdown of food so that it can
be absorbed
Mouth
•Where digestion starts
•Mechanical digestion: physical breakdown of food
•Chemical digestion: chemical breakdown of food
•Contains salivary glands
•Secrete saliva (spit)
•Contains amylase
•Enzyme that breaks down carbohydrates in
mouth
•Dissolves food
•Cleans mouth and teeth
Pharynx (Throat)
•Connects mouth to
esophagus
•Contains epiglottis
•Flap of tissue covers
windpipe when you
swallow
Esophagus
•Straight tube from pharynx to stomach
•Peristalsis: Wave-like muscle contraction that
sends food through the digestive system
Stomach
•Peristalsis in the stomach breaks down food into
chyme
•Chyme: Mix of food and digestive juices
•Digestive juices contain enzymes
•Enzymes: chemicals that break down food
more quickly
Stomach
•Absorbs a small amount of nutrients
•Liquids pass quickly
•Solids pass more slowly (a few hours)
•Carbohydrates pass the quickest (1 hour)
•Proteins pass at a medium rate
•Fats pass the slowest (3-6 hours)
Movement in Small Intestine
•Mixing and peristalsis constantly occurring
•Chyme takes 3-10 hours to pass through
Small Intestine
•Absorbs most of the nutrients from food
•Intestinal villi: hair-like structures that increase the
surface area
•More surface area = more absorption
•Area of your SI…. The size of a tennis court!
Large Intestine
•Diameter is larger than small
intestine
•Absorbs water and salt from
chyme
•Forms and stores feces
•No digestive function
•Secretes mucus (helps things
sliiiiiiide)
Feces
•Undigested material
•75% = water, mucus, bacteria
•Color comes from bile
•Odor comes from bacteria
Liver
•Just below the diaphragm
•Maintains blood and sugar
(carbohydrates) levels
•Removes damaged red blood
cells
•Removes toxins
•Drugs and alcohol
Liver
•Makes bile: yellowish liquid
•Breaks down fats
Gall Bladder
•Stores bile
between meals
Pancreas
•Makes pancreatic juice
•Insulin: helps absorb
carbohydrates
•Pepsin: enzyme that
breaks down proteins
•80% cases caused by
bacteria
•Causes severe stomach
pain
•If a hole forms, person
needs surgery
•Liver is damaged and no longer
functions well
•Liver damage caused by
cirrhosis CANNOT be reversed
•Caused by drugs, alcohol, and
certain diseases (hepatitis)
•Person starves them self
because the person thinks
they are overweight
•Affects girls much more
than boys
•Can cause death
•Person eats A LOT, then
throws it up
•Can cause death
•Caused by eating more
than you need, lack of
exercise, genetics,
hormones
•Cause MANY health
problems
•1 in 6 kids are obese