Download Digestive system Notes PP

1.
2.
3.
When you swallow, your food
is inside a 30-foot food tube.
It’s a winding canal that leads
from your mouth to your
rectum.
Those hunks of food must be
broken down into simpler
substances. Your cells can’t
use the food you eat. The
process of breaking down
chemicals into something your
body can use is digestion.
This process takes place in
the food canal. As it is broken
down, it is absorbed into your
blood and blood carries it to
cells throughout the body.
4. There are two
basic ways of
getting fuel:
•
•
Create your own
food using sunlight
through the process
of photosynthesis
Eat living or
formerly living
things. (Animals)
Digestion starts
with your teeth and
tongue.
5. Types of teeth
a. Incisors (8) work like
scissors. They cut.
b. Canines (4) sharp,
pointy teeth that are
used for ripping and
tearing.
c. Bicuspids (8) have
two points. They grind.
d. Molars (8) they
grind.
6. Mouths contain many kinds of
bacteria. Your mouth is the
most contaminated part of your
body. Bacteria in your mouth
devours food you and it
produces acid. The acid
attacks the enamel of your
teeth.
7. The hardest substance in your
body is enamel which covers
your teeth. Once enamel is
gone it cannot be replaced by
the body.
8. The jobs of the tongue:
a.
b.
c.
Taste
Chew
Helps with swallowing
9.
Your tongue and cheeks keep
food between your upper and
lower teeth. Your tongue rolls
the food into a ball. Your teeth
batter down the food into bits.
As this takes place, salivary
glands make a saliva that is
squirted into the food to soften
and moisten it. Your mouth
makes about a quart of saliva
a day.
10. Saliva contains chemicals
called enzymes which breaks
down starches into sugar.
11. There are 700 different
enzymes in your body.
Amylase (enzyme) changes
starch into sugar.
12. The jobs of enzymes:
a.
b.
Controlling the release of energy in
the body. Ex. One piece of chocolate
cake can raise a 100 lb persons
temp. to 117 degrees.
Food breakdown
13. When you are done chewing, you
swallow. When you swallow
doors close above and below the
back of the throat at the pharnyx.
Food cant go into your nose or
lungs. The door that covers your
trachea to stop food from going
down is called the epiglottis. The
mouthful of food goes down the
esophagus, approximately 10 in,
long. Food does not free fall into
the stomach. The food is
squeezed down the esophagus
by muscles. That’s why you could
swallow standing on your head.
14. It only takes 2-7 seconds for
your food to travel down the
esophagus to your stomach.
There is a valve at the bottom of
the esophagus that controls the
amount of food that goes into
your stomach.
15. Glands are bags of liquids in your
body. Some are large and some
are small.
16. Glands dump their liquids
through ducts into your mouth,
stomach and small intestines and
they will help with digestion. After
leaving your esophagus, food
goes into your stomach for 3-4
hours.
17. Your stomach can hold 1.5 quarts
of food.
18. In your stomach, food is in a
strong acid, while the stomach
churns it about.
19. Your stomach walls are three
layers of smooth muscle
(involuntary). Millions of tiny
glands in the stomach walls
make a liquid. The acid and the
enzymes in the liquid digest the
food.
20. The acid can break down meats
and kills bacteria. Your stomach
has a mucous lining, which
protects it from the acid. Any
breaks in the lining and in a
couple of hours the stomach will
have eaten a hole in itself
21. When you are tense or
nervous, extra acids go into
the stomach. These acids
cause ulcers.
22. Ulcers are sores inside
your stomach.
23. The opening in the bottom
of the stomach is called the
pyloric valve.
24. Opens every few minutes
to allow a couple of
spoonfuls of food into the
small intestine.
25. Now the food is mashed up
into a milky liquid called
chyme.
26. The small intestine is a 20
ft. long curly tube with a
shaggy lining. It has
millions of tiny villi on the
inside surface.
27. Villi are fingerlike things
that absorb the valuable
parts of the useful food in
to the bloodstream.
28. Your small intestine has its
own digestive juices which
are used for the final food
breakdown. The walls hug
and squeeze food along in
an action called peristalsis.
29. All of the squishing and squeezing
makes a lot of noise. That’s your gut
rumbling. It takes 8 hours for food to
make its way through the small
intestines.
30. Most digestion takes place in the small
intestine. The unused food that leaves
the small intestine and travels into the
blood stream goes to your liver.
31. You have two large glands that put juices
into your small intestine. These two
glands are the liver and pancreas.
32. The liver is the largest gland in your
body. It is reddish-brown in color. It is
located on the right side of your
stomach.
Jobs of the liver:
1. Make bile. Bile dissolves fat into
tiny pieces so it can be digested. The
bile leaves the liver and is stored in
the gall bladder.
2. The gall bladder stores the bile
until it is needed in the small
intestines.
3. The liver stores food. Blood picks
up nutrients and other food in the
small intestine. The food goes to the
liver and the liver stores it.
4. The liver releases the stored food
into the bloodstream slowly day and
night
33. Food is stored in many
parts of your body.
This stored food is
called fat. Fat is under
your skin to keep you
warm. Fat is about 1/7
of your weight.
34. Your pancreas is
shaped like a carrot. A
duct takes the
pancreatic juice into the
small intestine.
Job of the pancreas
a. Makes chemicals that
digest all types of
foods.
35. Your intestines contains a whole population of
bacteria. Bacteria are tiny microscopic
creatures. Only a few bacteria mean trouble to
humans.
Why bacteria is good:
a. Devours remains of food in your intestines.
b. Secrete vitamins K, B12, thiamine and
riboflavin.
36. Bacteria are not only in your food canal, but
also in every crack and crease on your surface.
There are more bacteria living on you, than
there are people living on earth. Your body’s
bacteria could fill a regular size soda can.
37. The non useful food parts move out of the small intestine
and by the appendix. There is no known job for the
appendix.
38. The unused parts and water move into the large
intestine.
39. The jobs of the large intestine:
a. Recycles water for body use.
b. as the water is absorbed, the mass becomes fairly thick.
40. The end of the large
intestine is called the
rectum.
41. The jobs of the
rectum:
a. Stores waste until
passed from the body.