Digestive System
Function: disassemble the food you eat into molecules your body can use as energy.
Parts:
Mouth- food enters and process begins
-Mechanical Digestion- food is chewed, mixed and churned
-Chemical Digestion- changing food on a molecular level through enzymes (proteins that speed up
chemical reactions in the body)
Esophagus- Muscular tube moves food to the stomach using peristalsis (waves of muscle contractions)
Stomach- food is digested mechanically by peristalsis and chemically by digestive enzyme pepsin and
hydrochloric acid
Small Intestine-most chemical digesting happens here. Absorption of nutrients (increased by villi- small
protection that increases surface area)
- Liver- produces bile (breaks up fat particles)
- Gall Bladder- stores bile
- Pancreas- produce enzymes that flow into small intestines that help break down starches, proteins
and fats
Large Intestine – absorbs water from undigested chime into the bloodstream. Contains bacteria to break down
remaining nutrients
Rectum/Anus- expels waste
Digestive Secretions
Secretion/Enzyme
Location
Function
Saliva
Pepsin
Hydrochloric Acid (HCl)
Bile
Insulin
Mouth
Stomach
Stomach
Liver
Pancreas
Begins chemical digestion
Breaks down food
Breaks down food
Breaks down fat
Breaks down starch, protein and fats