Transcript Digestive System?

WHAT IS DIGESTION?
Form Group 3C
12th January 2007
Digestion ?
Digestive System?
• Process of breaking down • An organ system, is
large insoluble molecules
made of a group of
(e.g starch, proteins, fat)
organs all working
into smaller soluble
together.
molecules.
• Each organ has a
particular function and
only by working
together will they get
the job done.
What do you really know?
Digestion Process
1. Mouth
Salivary gland
In the mouth the food is broken into small
pieces and mixed with saliva.
2. Gullet or oesophagus
oesophagus
Part of the tube
responsible
for carry the food from
the mouth to the stomach.
3. Stomach
• Is a muscular bag
that produces gastric
juices.
• It includes dilute
hydrochloric acid and enzymes
that we call proteases.
4. Gall Bladder or the bile
Does not contain any enzymes but it
breaks down the fats into very small
droplets, giving a larger space to the fat
enzymes called lipases can work in the
small intestine.
Bile is produced by
the liver.
5. Pancreas
The pancreas
produces the
pancreatic
juice.
6. Small and Larger Intestine
•
Most food products are
absorbed in the small
intestine.
Small intestine
•
The large intestine is
responsible for
absorption of water and
excretion of solid waste
material.
Larger
intestine
rectum
Digestion happens in 2 ways.
Physical
The shape of the
food must be
physically changed
so that it can fit in
the digestive
system.
Chemical
This allows useful
chemicals to be
released and dissolve
in the blood. To be
broken down
chemically, the bonds
must be broken.
Enzymes...
Amylase
Protease
Lipase, Protease and Amylase.
Class Notes...
• Digestion involves breaking down large
insoluble food molecules ( like starch,
protein and fats) into smaller soluble
molecules.
• Find out what to write about the
function of which organ in the digestive
system...
(mouth,gullet, stomach, bile, pancreas,
smaller and larger intestine).