Transcript Digestive System

Chapter 14
 Alimentary

Canal
Digests and absorbs
food
 Accessory
digestive
organs

Assist the process of
digestion
A.
B.
C.
D.
5
6
7
8
 Where
food enters digestive system
 1st organ of alimentary canal
 Mechanical and chemical digestion

Contains accessory organs:


Teeth- masticate (chew) food
Salivary glands- secretes saliva
 Saliva:



moistens and helps bind food together into a bolus
Contains enzymes that start to break down starch
Dissolves food so it can be tasted
A.
B.
C.
D.
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34
36
38
 Tube
connecting
mouth and esophagus
 2nd part of alimentary
canal
 Walls of tube contain
smooth muscle that
contract to propel
food down (called
peristalsis)
A.
B.
C.
D.
3-4 in
4-5 in
5-6 in
7-8 in
 Connect
pharynx to
stomach
 3rd part of alimentary
canal
 Conducts food by
peristalsis to the
stomach
A.
B.
C.
D.
6
7
8
9
in
in
in
in
 Connect
esophagus to small
intestines
 4th part of alimentary canal
 C shaped
 Food enters and is stored
 Stomach churns and mixes food
with gastric juices and
enzymes to form chyme (heavy
cream)
A.
B.
C.
D.
1 gallon
0.5 gallon
1.5 gallon
0.75 gallon
Digestion takes place primarily in the stomach.
Myth:
 Most digestion takes place in your small
intestines
If you cut down on your food intake, you'll
eventually shrink your stomach so you won't
be as hungry.
Myth:
 Once you are an adult, your stomach stays
the same size unless you have surgery on it
Thin people have naturally smaller
stomachs than people who are heavy.
Myth:
 While it may seem hard to believe, the
size of the stomach does not correlate
with weight or weight control. People
who are naturally thin can have the same
size or even larger stomachs than people
who battle their weight throughout a
lifetime.
Exercises like sit-ups or abdominal crunches
can reduce the size of your stomach.
Myth:
 No exercise can change the size of an organ
One way to reduce acid reflux is to lose as
little as 2 to 3 pounds.
Fact:
 Losing just 2 pounds of weight from the
abdominal area can make a difference.
Pregnancy is about the best example of
this, as the baby grows and pushes against
the internal organs, heartburn increases;
but once the baby is born and the
pressure is relieved, the heartburn is,
too.
Eating before bed can make you gain weight
faster than if you eat the same foods during
the day.
Myth:
 People gain weight when we take in more
calories than we burn up, it doesn’t matter
when you take in the calories
A 200-calorie snack of peanut butter and crackers
is more likely to control your appetite than just
eating 200 calories' worth of crackers.
Fact:
 Fats digest much slower than carbohydrates, and
they remain in the stomach longer, which means
we naturally feel full longer after eating a snack
that contains at least some fat . In addition,
simple carbohydrates (like crackers) elicit a
quick rise in blood sugar and insulin levels, which
subsequently drop just as quickly, causing
dramatic shifts in both mood and appetite.

Connects stomach to
large intestine

3 parts:



Duodenum
Jejunum
Ileum
5th part of the alimentary
canal
 Where most of digestion
and absorption occurs
 Capillaries in the cells of
the small intestine absorb
the digested food for use
by the bodies cells

A.
B.
C.
D.
3
4
5
6
m
m
m
m


Liver- secretes bile into small intestines to breakdown
fats
 When bile is in excess it is stored in gallbladder
Pancreas- produces and secretes enzymes into small
intestines to break down all types of foods
 Produces hormones insulin and glucagon that
regulate blood sugar
Liver
 Connects

small intestine and anus (exit)
4 parts:




 6th
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
part of alimentary canal
 Dries out food residues by absorbing water
 Lubricates feces with mucus
 Removes residues as feces through rectum
A.
B.
C.
D.
4-6 hours
6-8 hours
8-10 hours
10-12 hours