Download Digestive System

Digestive
System
Organs of the Digestive System
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Mouth
Esophagus
Stomach
Small Intestine
Large Intestine
Rectum
Anus
Functions of the Digestive
System
1.
Ingestion = Food
enters the mouth.
Functions of the Digestive
System
1.
2.
Ingestion = Food enters the
mouth.
Digestion =
Process that breaks
food down into
small molecules that
can be used by cells
Functions of the Digestive
System
1.
2.
Ingestion = Food enters the
mouth.
Digestion = Process that
breaks food down into small
molecules that can be used by cells
a) Mechanical digestion =
Food is chewed, mixed,
or churned.
b) Chemical digestion =
Breaks down large food
molecules using chemical
reactions
Functions of the Digestive
System
1.
2.
3.
Ingestion = Food enters the
mouth.
Digestion = Process that
breaks food down into small
molecules that can be used by
cells
Absorption =
Small molecules of
food are moved into
the bloodstream.
Functions of the Digestive
System
1.
2.
3.
4.
Ingestion = Food enters the
mouth.
Digestion = Process that
breaks food down into small
molecules that can be used by cells
Absorption = Small
molecules of food are moved
into the bloodstream.
Elimination =
Wastes made of
unabsorbed food
molecules pass out of the body.
Large Intestine
Which is not a function of
the digestive system?
a)
b)
c)
d)
Breaking down food into
molecules the body cells can
use
Absorbing food molecules
into the blood to deliver to
the body cells
Changing waste into
molecules the body can
use
Eliminating undigested waste
from the body
Organs of the Digestive
Tract
1.
Mouth = Digestion starts here.
Organs of the Digestive
Tract
1.
Mouth = Digestion starts here.
a) The tongue & teeth mechanically
break food up.
Organs of the Digestive
Tract
1.
Mouth = Digestion starts here.
a) The tongue & teeth mechanically
break food up.
b) Saliva chemically digests food.
a) Saliva = Mostly made of
water, also contains mucus
and enzymes, which break
food molecules down with
chemical reactions.
Organs of the Digestive
Tract
1.
Mouth = Digestion starts here.
a) The tongue & teeth mechanically
break food up.
b) Saliva chemically digests food.
a) Saliva = Mostly made of
water, also contains
mucus and enzymes, which break
food down with chemical reactions
c) When swallowing, the epiglottis
(a small flap of tissue) automatically
closes over the trachea (windpipe).
Organs of the Digestive
Tract
2.
Esophagus
a) Smooth muscles force food into the
mucus-lined esophagus.
b) Rhythmic muscular
contractions
(peristalsis) push food
downward.
Organs of the Digestive
Tract
3.
Stomach
a) Food undergoes mechanical digestion
when stomach muscles churn the food
into chyme, a soupy substance.
b) Chemical digestion
happens when hydrochloric
acid (HCl) and pepsin
break down the complex
proteins.
c) Peristalsis pushes the chyme
toward stomach’s exit after 2-4 hours.
Which is not an example
of mechanical digestion?
a)
b)
c)
d)
Teeth chewing food
Tongue breaking up
food
Smooth muscles in
stomach churning
food
Hydrochloric acid
breaking down
proteins
Organs of the Digestive
Tract
4. Small Intestine (4-7 meters long)
a) Mechanical & Chemical
digestion happen here.
b) Intestinal juice
(full of enzymes)
breaks down food.
Organs of the Digestive
Tract
4. Small Intestine (4-7 meters long)
a)
b)
Mechanical & Chemical digestion happen here.
Intestinal juice (full of enzymes) breaks down food.
c) Accessory Organs
•
Liver = Bile is
produced here (Bile
breaks up fats like
dish detergent
breaks up grease.).
Organs of the Digestive Tract
4. Small Intestine (4-7 meters long)
a)
b)
Mechanical & Chemical digestion happen here.
Intestinal juice (full of enzymes) breaks down food.
c) Accessory Organs
•
Liver = Bile is produced
here (Bile breaks up fats
like dish detergent breaks
up grease.).
•
Gall bladder = Bile
is stored here until
released into the small intestine.
Organs of the Digestive
Tract
4. Small Intestine (4-7 meters long)
a)
b)
Mechanical & Chemical digestion happen here.
Intestinal juice (full of enzymes) breaks down food.
c) Accessory Organs
•
•
•
Liver = Bile is produced
here (Bile breaks up fats
like dish detergent breaks
up grease.).
Gall bladder = Bile is
stored here until released
into the small intestine.
Pancreas = Produces
pancreatic juices, like insulin, that
are released into the small intestine to break
down starches
Organs of the Digestive
Tract
4. Small Intestine (4-7 meters long)
a)
Mechanical & Chemical digestion happen
here.
b) Intestinal juice (full of
enzymes) breaks down food.
c) Accessory Organs
• Liver
• Gall bladder
• Pancreas
d) Digested food is absorbed
through the villi, ridges in the small
intestine, into capillaries that carry the
nutrients to all of the body cells.
Organs of the Digestive
Tract
4. Small Intestine (4-7 meters long)
a)
b)
c)
Mechanical & Chemical digestion happen
here.
Intestinal juice (full of enzymes)
breaks down food.
Accessory Organs
•
d)
Liver, Gall bladder, Pancreas
Digested food is absorbed
through the villi into capillaries that carry
the nutrients to all of the body cells.
e) By the time food leaves the small
intestine, it is empty of all nutrients
except water.
Where does absorption of
nutrients take place?
a)
b)
c)
d)
Mouth
Stomach
Small intestine
Liver
Organs of the Digestive
Tract
5. Large Intestine (1.5 meters long)
a) Undigested food spends 18–24 hours
here, and most of the water is
re-absorbed. This
waste material is now
called feces.
Organs of the Digestive
Tract
5. Large Intestine (1.5 meters long)
a)
Undigested food spends 18–24 hours here, and most of
the water is re-absorbed.
b) Helpful bacteria
living in the large
intestine make
vitamins B and K.
Organs of the Digestive
Tract
5. Large Intestine (1.5 meters long)
a)
b)
Undigested food spends 18–24 hours here, and most of the
water is re-absorbed.
Helpful bacteria living in the
large intestine make vitamins
B and K.
c) Materials not
absorbed form into
solid waste (dead
bacteria, some fat and
protein, undigested
food, dried out parts of
digestive juices, and old intestinal cells).
Organs of the Digestive
Tract
5. Large Intestine (1.5 meters long)
a)
b)
c)
Undigested food spends 18–24 hours here, and most of the water is
re-absorbed.
Helpful bacteria living in the large
intestine make vitamins B and K.
Materials not absorbed form into
solid waste (dead bacteria,
some fat & protein, undigested
food, dried out parts of digestive
juices, and old intestinal cells).
d) Solid waste passes
into the rectum and is stored until it is
eliminated from the body through the anus.
Organs of the Digestive
Tract
6. Large Intestine (1.5 meters long)
Attached to the large intestine is a
worm-like structure called the
appendix.
Little is understood about the function of
the appendix. The function of the
appendix is unknown. One theory is that
the appendix acts as a storehouse for
good bacteria, “rebooting” the digestive
system after illnesses. Other experts
believe the appendix played a part in the
digestion of early-man’s diet.