Transcript No Slide Title

 Takes in Food (mouth)
 Hydrolyzes macromolecules to their basic
units. (see next slide)
 Absorbs the broken down food into the
blood stream which delivers it to your tissues
and organs.
Carbohydrate Digestion
Salivary amylase (made by salivary glands)…works in mouth Pancreatic
amylase (made by pancreas)…works in small intestine Maltase (made by
small intestine)…works in small intestine Lactase (made by small
intestine)…works in small intestine
Protein Digestion
Pepsin (made by stomach)…works in stomach
(made by pancreas)…works in small intestine
by small intestine)…works in small intestine
Trypsin
Peptidases (made
Fat Digestion
Lipase (made by pancreas)…works in small intestine
Nucleic Acid Digestion
Nuclease (made by pancreas)…works in small intestine Nucleosidases
(made by small intestine)…works in small
intestine
 CHEWING: breaks food into smaller pieces (increases
surface area) “Mechanical” digestion (20 baby teeth, 32 adult)
 SALIVA: slightly basic
SWALLOWING: soft palate is pushed up to close nasal
passages, trachea moves up under the epiglottis to close the
glottis.
 PERISTALSIS: muscle contraction
that moves food through the digestive
tract.
 Moves food from mouth to stomach in
5-8 seconds.
Lower Gastroesophageal Sphincter:
entrance of esophagus to stomach. Food
passes when relaxed.
Stores food and initiates digestion of protein.
Very muscular. It contracts to mix food,”mechanical
digestion”
Lined with millions of glands that secrete HCl
(acidic) and Pepsin (enzyme) “chemical digestion”
Food stays there for 2-4 hours
Gastric bypass attaches the upper part of the
stomach to the middle of the small intestine.
Structure:
 Muscular tube about 6m long
 “Small” because of its diameter
 Duodenum (first 25 cm) of small intestine…this is where
enzymes from the pancreas and liver are collected.
Bile from the liver causes fat droplets to disperse in water.
Since the fat molecules are smaller, lipase can now work.
This is where nutrients are absorbed into the blood.
 Food stays in the small intestine for 3-5 hours.
 Also known as the “Colon”
 Only contains things that can’t be digested…waste
 1.5m long and 6.5cm wide
 Water is absorbed into the blood here
 Bacteria live in here to further break down matter,
produce B complex vitamins (coenzymes) and most of the
vitamin K (needed for blood clotting) needed by our bodies

18-24 hours in the large intestine before the
feces reaches the rectum and leaves the anus.
Total time it takes to digest is 24-33 hours