Topic: Digestive System
Aim: Describe the parts and functions of the digestive
system.
Do Now:
1. Pass up your Food Label lab.
2. Take out your digestive system reading notes.
3. Identify the life process that requires the food we
ingest and digest.
http://www.youtube.com/watch?v=bo2Ape8JHqA
HW: Read text pgs. 525-529. Complete p. 529 #’s 1 -5.
Write the question and answer.
Did you know....
• Americans eat about 700 million pounds
of peanut butter.
• Americans eat over 2 billion pounds of
chocolate a year.
• In your lifetime, your digestive system
may handle about 50 tons of food!!
• What you ate for breakfast that was not
digested will come out in about 48 hoursnormally.
• From intake to outlet, the digestive
tract is about thirty feet long.
1. Describe the function (job) of the
digestive system.
• Breakdown of food into small
molecules so that they can be
absorbed into the blood and enter
your cells
2. Identify the structure where digestion
begins (or start).
• Mouth
• Oral cavity
TEETH
Incisors
Canine
Premolars
What kind
of
digestion
occurs in
your
mouth?
Molars
Tongue
Salivary
glands
Opening of a
salivary gland duct
“Wisdom”
tooth
3. How does the mouth CHEMICALLY
digest food?
• Saliva contains the
ENZYME amylase
which helps break
down
CARBOHYDRATES
in your food.
Where does the
saliva come
from???
Salivary
glands release
saliva into the
mouth.
Mumps is a highly contagious viral illness which
causes swelling of the parotid gland.
A vaccine is given to
children above one year of
age along with rubella and
measles vaccines. IMMRV
vaccine also available
which gives protection
against mumps, measles,
rubella and chicken pox.
4. How does the mouth MECHANICALLY
digest food?
• Your TEETH grind your food when you CHEW,
and your tongue pushes the food around your
mouth.
Did you know....
• We make 1 to 3 pints of saliva a day.
• Your teeth started growing 3 months
before you were even born.
• The hardest substance in your body is
the enamel on your teeth.
• As you are sitting there listening, more
than 100 million germs are swimming,
feeding, reproducing, and making waste
in the area behind your lips. In your
mouth there are more living things than
there are people in Australia and Canada
combined.
Uvula
Through history, scientists have
had many theories about the
uvula. Among them:
•That it once helped guide the flow
of food and water.
•That it induces the gag reflex.
And therefore isn’t the best place
to get a piercing.
•That it contributed to “chronic
cough.” A problem that 19thcentury doctors treated with a
“simple” “clipping” procedure.
Uvula
Several such studies have concluded
that the uvula is really good at
releasing saliva. A lot of saliva, in a
really short amount of time.
Because the uvula is basically unique
to humans, scientists basically agree
that it primarily serves as an accessory
to speech. You know what it’s like to
have your throat go dry before talking
to a large group? The uvula is there to
provide the proper lubrication for
complicated human speech.
5. What is the function of the EPIGLOTTIS?
• The epiglottis is a FLAP of SKIN that COVERS
the windpipe when you SWALLOW food or
liquid.
6. What happens when you cough or
choke?
• When you cough or choke, it means the
EPIGLOTTIS did not cover you WINDPIPE
sufficiently.
7. Describe the function of the
ESOPHAGUS?
• It connects your throat to your stomach.
8. How does the esophagus push food
down into the stomach?
• Smooth muscles on the walls of your
esophagus move in a wave motion to direct the
food to the stomach.
• PERISTALSIS
Opening to stomach from
the esophagus
Topic: Digestive System
Aim: Describe the parts and functions of the digestive
system.
Do Now: Pass up your HW.
Complete the exit card using the diagram on the next
slide.
HW: Midterm Remediation Castle Learning due Thursday.
Oral cavity
A
B Salivary glands
C Esophagus
E
F
D Stomach
H
G
I
J
9. Describe the function of the stomach.
9. Describe the function of the stomach.
• The stomach HOLDS
the food you swallow,
where it is BROKEN
DOWN food into a
liquid mixture by
GASTRIC JUICES and
strong MUSCLES in
stomach wall
• MECHANICAL and
CHEMCIAL digestion
http://www.youtube.com/watch?v=o18UycWRsaA
10. Identify the chemical in the stomach
that kills bacteria that may be in the food
that you eat.
• Hydrochloric acid
http://www.youtube.com/watch?v=SWMWsOXlBwE
Did you know....
• An adult’s stomach can hold
approximately 1.5 liters of material.
• Food sloshing in the stomach can
last 3-4 hours.
• The stomach's wall is lined with
three layers of powerful muscles.
https://www.youtube.com/watch?v=URHBBE3RKEs
SMALL INTESTINE
Length = 4-7 meters
Why is it called the SMALL intestine?
11. Describe the TWO functions of the
small intestine.
• Food is further digested.
(CHEMICAL digestion is COMPLETED)
• Food (nutrients) is absorbed by your body.
12. Identify 3 structures that aid (HELP) in
chemical digestion in the small intestine.
• Pancreas
• Liver
• Gall bladder
13. Describe the pancreas, liver and gall
bladder aid in chemical digestion in the SI.
• Pancreas secretes juices that help digest
proteins and fats.
(CHEMICAL DIGESTION)
13. Describe the pancreas, liver and gall
bladder aid in chemical digestion in the SI.
• Liver produces
bile and helps the
body absorb fats.
• Gall bladder
stores and
secretes bile.
BILE
Bile
emulsifies
fats.
Liver
Stomach
Gall
bladder
Small
Intestine
Pancreas
14. How are nutrients absorbed in the small
intestine?
• Wall of SI lined with VILLI (fingerlike
projections)
Which blood vessels are found inside each villus?
Topic: Digestive System
Aim: Describe the parts and functions of the digestive
system.
Do Now: Take out your digestive system reading notes.
HW: Midterm Remediation Castle Learning due tomorrow.
Flamin’ Hot Cheetos Reading Questions
If you stretched out an
adult's small intestine, it
would be about 22 feet
long.
1. Identify the type of
digestion that occurs in
the SI.
2. Identify the structures
that help chemically
digest food in the SI.
3. Explain what occurs once
digestion in completed.
http://www.youtube.com/watch?v=JCA
9HQ795i8
VILLI
15. Describe the function of the large
intestine.
• The large intestine
removes most of
any remaining
minerals or
FLUIDS that the
body can use from
the waste.
• Fluid = WATER
Did you know....
• Within the colon, a typical
person harbors more than 400
distinct species of bacteria.
16. Once water is absorbed in the LI, what
is the waste called?
• Stool
• Feces
17. Identify the structure that temporarily
stores stool?
• Rectum
18. Identify the structure that removes
stool from the body.
• Anus
How the bacteria in the large intestine are
beneficial to humans?
• Produce vitamins
• Bacteria feed on undigested material
(cellulose)
If you squeezed out all of the bacteria
that lives in your intestines, you could
almost fill up a coffee mug. Anyone want
a sip?
Let’s Review: Identify the digestive organ described.
1. Where chemical digestion begins. Oral cavity
2. Site of water absorption. Large intestine
3. All chemical digestion is completed here.Small
intestine
4. Where bile is stored. Gall bladder
5. Where feces is formed. Large intestine
6. Where mechanical digestion begins. Oral cavity
7. Releases many enzymes into the SI. Pancreas
8. Pushes food into the stomach. Esophagus
9. Produces saliva. Salivary glands
10. Where the absorption of nutrients occurs.Small
intestine
1. Lining is protected by a mucus layer. Stomach
2. Lined with villi. Small intestine
3. Produces bile. Liver
STARCH
Oral cavity
A
B Salivary glands
C Esophagus
Liver
E
F
Gall bladder
Large G
intestine
PROTEINS
D Stomach
H Pancreas
I Small
intestine
J Rectum
Identify the organs of the digestive system that
aid in digestion but food does not pass
through.
Gallstones occur when
 Bile forms solid particles
(stones) in the gallbladder
 Stones form when the amount
of cholesterol or bilirubin in the
bile is high.
Risk factors for the formation of
cholesterol gallstones include
the following:
 female gender
 being overweight,
 losing a lot of weight quickly on
a "crash" or starvation diet
taking certain medications such
as birth control pills or
cholesterol lowering drugs
As the stones mix with liquid
bile
they can block the outflow of
bile from the gallbladder
can block the outflow of
digestive enzymes from the
pancreas.
If blockage persists, these
organs can become inflamed.
Inflammation of the gallbladder
is called cholecystitis.
Inflammation of the pancreas is
called pancreatitis.
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 diarrheal illnesses.
Other experts believe the
appendix is just a useless
remnant from our evolutionary
past. Surgical removal of the
appendix causes no
observable health problems.
http://www.youtube.com/watch?v=_QYwscALNng
STARCH
Oral cavity
A
B Salivary glands
C Esophagus
Liver
E
F
Gall bladder
Large G
intestine
PROTEINS
D Stomach
H Pancreas
I Small
intestine
J Rectum
Salivary glands
Esophagus
Liver
Gall baldder
Small intestine
Appendix
Stomach
Pancreas
Large
intestine
http://www.youtube.com/watch?v=bo2Ape8J
HqA
http://www.youtube.com/watch?v=ttQtDfv6d
Co
Oral cavity
Gall
bladder
Large
intestinne
Stomach
Pancreas
Small intestine
Rectum
Let’s review…
1.Describe the FUNCTION of the digestive system.
2.Identify the type of digestion that occurs in the
mouth.
3.Identify the tube and the process that pushed
food into the stomach.
4.Identify the flap of tissue that prevents you from
choking when swallowing food or liquid.
5.Identify the type of digestion that occurs in the
mouth.
6.How is the stomach lining protected from the
hydrochloric acid?
Oral cavity
A
B Salivary glands
C Esophagus
E
F
D Stomach
H
G
I
J
The main function of the human
digestive system is to
1) rid the body of cellular waste materials
2) break down large molecules so they
can enter cells
3) break down glucose in order to release
energy
4) change amino acids into proteins and
carbohydrates
Food is ingested through the
1) salivary glands
2) small intestine
3) mouth
4) rectum
Mechanical digestion in the oral
cavity is primarily the result of
1) peristalsis
2) chewing food
3) absorption
4) egestion
Chemical digestion in the mouth is
the result of
1) enzymes
2) hydrochloric acid
3) bile
4) pancreatic juice
Food that is swallowed enters the
1) stomach
2) small intestine
3) esophagus
4) large intestine
The esophagus pushed food
down into the stomach by the
involuntary process of
1. digestion
2. peristalsis
3. absorption
4. excretion
Identify the type of digestion that
takes place in the stomach.
1) mechanical digestion
2) chemical digestion
3) both mechanical and chemical
digestion
How does mechanical digestion in
the stomach occur?
1) enzymes
2) hydrochloric acid
3) peristalsis
4) mucus
How does chemical digestion in the
stomach occur?
1) peristalsis
2) enzymes
3) mucus
4) ulcers
Which substances in the small
intestine of humans serve to
increase the surface area for
absorption?
1. intestinal glands
2. villi
3. pseudopodia
4. cilia
Identify how the stomach lining is
protected from hydrochloric acid.
1) peristalsis
2) mucus
3) enzymes
4) bacteria
Identify the type of digestion that
occurs in the small intestine.
1) mechanical digestion
2) chemical digestion
3) both mechanical and chemical
digestion
Which statement regarding the small
intestine is incorrect?
1. Villi on the lining of the small intestine
absorb nutrients into the blood.
2. Chemical digestion is completed in the
small intestine.
3. Mechanical digestion is completed in the
small intestine.
4. The small intestine is where most
digestion occurs.
Which structures in the small
intestine absorb nutrients into the
blood?
1. intestinal glands
2. villi
3. pseudopods
4. cilia
Which substances are released into the
small intestine of a human and aid in the
digestion of food?
1) bile, pancreatic juice, and intestinal juice
2) hydrochloric acid, pancreatic juice, and
intestinal juice
3) salivary amylase, intestinal juice, and
pancreatic juice
4) bile, hydrochloric acid, and salivary
amylase
https://www.youtube.com/watch?v=_QYwscALNng
Which statement regarding the large
intestine is correct?
1. The large intestine absorbs nutrients.
2. Chemical digestion is completed in the
large intestine.
3. Mechanical digestion is completed in the
small intestine.
4. The large intestine absorbs excess
water.