Download Louie`s Biology Travel Brochure - TangHua2012-2013

Human Digestive System
Travelling
by Duodenum Dynamics Ad
Agency
Model: Mr. BASS
We will visit Mr. Bass digestive system to
see how it works
Money: $2240/ one person
Tip:$105/one person
Maximum number of visiters:6
If you want to visit cardiovascular system or
somewhere else, please contact agency
Instruction
Instructor:
Ms. Win
Telephone:
56879213
Gathering Time and location:
Mr. Bass’s shoulder
March 22th, 9:00a.m.
This trip will help you
find out
• When you eat ice-cream, where does it go?
Is it magic that makes the ice-cream
disappear?
• Mum and Dad maybe tell you that the food
you eat is absorbed by your body, but how?
• People usually say that our stomachs help us
digest food, but does all the food become
little molecule only in the stomach?
Items suggest to bring
- digestive system passport (must bring or
you will not be allowed to visit)
- Umbrella
- mask (keep safety from HCl in stomach)
- Carsick medicine (may be useful when
experience physical digestion in stomach)
Let’s do this
NOW, PACK YOUR THINGS
AND LET’S START THIS
AMAZING TRIP
Some information
The function of digestive system:
• to ingest food
• Digest it to nutrients
• Eliminate indigestible remains
• It includes both the physical and chemical
process that reduce food to small soluble
molecules that can be absorbed.
Compare and Contrast
Mechanical digestion:
• large pieces of food becomes smaller
piece, readying them for the chemical
digestion
• Begin with chewing food in the mouth and
continues with the churning and mixing of
food in the stomach.
• Increasing surface area so enzyme can
work on them
Chemical digestion:
• Many different enzymes break down
macromolecules to small organic
molecules that can be absorbed.
Day One
Today, we will start our trip to have a comprehensive look at oral cavity
•
•
•
1.
2.
3.
4.
5.
Mouth: receive food, is bounded
externally by the lips and cheeks.
Start digestion of starch
Includes:
Hard palate
Soft palate
Teeth
Tongue
lip
Never, ever stand on teeth, or you will
become fragments
1.Tongue:
-directs food into teeth(help chewing)
-pushes chewed food to the pharynx
2. Lips:
-hold food in the oral cavity
-help direct food onto the teeth(help chewing)
3.Teeth:
-mechanical digestion: start cutting food into
smaller pieces
-2 parts: crown & root ( contains nerve)
4.Palate:
-separates the nasal cavity from the oral
cavity
- 2 kinds of palate
Hard palate:
-has bones
-places in the front
Soft palate:
-simply muscle
-behind the hard palate
-ends in the projection
called uvula
Some other thing:
Tonsil- helps to against infection
Salivary glands
-Produce saliva
-saliva moistens food, and contains
enzymes
There are three salivary glands in
our mouth:
-sublingual gland (beneath the
tongue)
-sub maxillary gland (under mouth)
-parotid gland ( in front of ears)
ducts into mouth in front of the
second molar
The physical and chemical digestion in our
mouth:
Physical: teeth chewing food
Chemical:
• salivary glands produce salivary amylase
• salivary amylase works on starch and converts
it into maltose
• the process is hydrolysis
Ｓｔａｒｃｈ+
Ｓａｌｉｖａｒｙ
ａｍｙｌａｓｅ
ｗａｔｅｒ－－＞
ｍａｌｔｏｓｅ
Salivary amylase works better in a neutral pH condition
There are both physical and chemical digestions happen in our
mouth.
DAY ONE’S CONCLUSION
WE WILL STAY IN SOFT
PALATE HOTEL TONIGHT
Day Two
Hotel: esophageal hotel
Activity: canoeing down into
esophagus (bring carsick medicine)
Pharynx
-back of people throat where oral and nasal
cavities meet each other
-it is the place where swallowing occurs
Epiglottis:
-it is a flap of tissue that close off the
opening of the trachea when people
swallow food
-keeps foods from entering the air passage
-usually, people will cough when food enters
into trachea in order to force it back to
esophagus
-very, very important to
human or we will
choke to death
Esophagus:
-the muscle tube leads
from the pharynx to
the stomach
-food moves down the
esophagus due to the
process of peristalsis
Peristalsis
• It is a rhythmical contraction of the
muscles in the esophageal wall
• Smooth muscle lining the esophageal wall
pushes food down
The pharynx and esophagus are pass ways
which let food go into stomach.
The peristalsis process facilitate the starch
digestion for mixing saliva with food.
Actually, nothing great happens in Day Two’s journey.
It is a pretty relaxing day
Take a good rest! Tomorrow's trip will be quiet dangerous and tired
DAY THREE
It will be an exhausting day. Take
a deep breath and we will enter
the abdominal cavity
The Abdominal Cavity
Structures:
1.Stomach
2.Liver
3.Pancreas
4. Gall Bladder
5.Instestines(small & large)
Cardiac Sphincter
When we leave the esophagus, we are in the cardiac sphincter
which is the connection between stomach and esophagus. Cardiac
sphincter are strong muscle. Its relaxation and contraction control
food entrance . It prevents the acid in stomach comes back towards
the esophagus.
Some
extra
note:
Heat Burn
•One problem is caused by the malfunction of cardiac sphincter.
•It is a burning sensation in the chest, just behind the breastbone or in the epigastria, the upper
central abdomen. The pain often rises in the chest and may radiate to the neck, throat, or angle
of the jaw.
•Heartburn is usually associated with regurgitation of gastric acid (gastric reflux) which is the
major symptom of gastro esophageal reflux disease. It may also be a symptom of ischemic heart
disease, though this is true for only 0.6% of those experiencing heartburn.
Stomach
-J-shaped organ which stores and
churns food
-churning helps physical digestion
of food
-churning results in the product
called chyme
chyme: a soupy liquid of food
-chemical digestion of proteins
begins in the stomach
-cardiac sphincter (lower
esophageal sphincter)
-pyloric sphincter
• band of muscle which closes off
the bottom of the stomach
• allows small amounts of chyme to
enter the intestine
•If it malfunction, chyme cannot
enter the small intestine and be
digested
chemical and physical digestion
in stomach
Chemical:
• There is gastric gland in stomach which produces gastric
juice
• Gastric juice is hydrochloric acid, pepsinogen
• When pepsinogen meets HCl, they produce pepsin
Pepsinogen + hydrochloric  pepsin
• Pepsin works on protein and changes it into peptides
Protein + water  peptides
pepsin
• In stomach, protein digestion starts
Pepsin works better in an acidic condition
How to control the stomach
secretions
•Gatrin: a hormone produce in
the lower part of the stomach
•Gastrin enters the bloodstream
and later stimulates gastric
gloands in the upper part of the
stomach to produce
pepsinogen and HCl
•HCl can burn the lining of the
stomach, so mucous is
produced to protect the
stomach lining
•HCl is acid which is erosive
Some problems:
If a portion of the stomach does get burned,
it is called an ulcer
DO NOT STAND NEAR THE
GASTRIC GLANDS!!!!!!!!!!!!!
WARNING
DAY THREE END
• We have finished the
visiting in our
stomach.
• Pretty dangerous uh…
• Today, we stay at
peptic hotel
• Tomorrow will be a
stunning experience
as well, be prepared
Day Four
We are going to see the small intestine, liver, gall bladder and pancreas. Their
relationships are pretty complex and hope you have a clear understanding when we come
back to the hotel.
Keep your heads up and watch out. Danger is
still hidden somewhere
Liver
An essential organ
which places many
roles in people’s lives
1.
produce bile
2.
Destroys old red blood cell and converts
hemoglobin to a product in bile
3.
Stores glucose as glycogen after eating and
breaks down glycogen to glucose between
eating to help maintain glucose (sugar) level
of blood
4.
Produces urea from the breakdown of amino
acid (deamination)
5.
Makes blood protein from amino acids
6.
Detoxifiers the blood by removing poisons
substances and metabolizing them
(converting them into harmless substance)
7.
Stores iron and vitamin A, C, E
EMUSIFIER
Bile has non-polar and polar head. When it meets fat droplets, the
non-polar head injects the fat which cause the droplet become
polar and can disperse in water
fat+ water  fat droplets
Bile salt
Gall Bladder
•the organ places under the liver
and attach to it
•Store bile which is produced by
liver
•Bile is not an enzyme
Pancreas:
-produces digestive enzymes and
sodium bicarbonate
-pancreatic juice:
•Pancreatic amylase, trypsin, lipase
and sodium bicarbonate
•Secreted into the duodenum via
the pancreatic duct
1. Pancreatic amylase: act
on starch to convert it to
maltose
2. Trypsin: breaks down
proteins to peptides
3. Lipase: breaks down fat
droplets into glycerol
and 3 fatty acids
4. NaHCO3: is a base and
neutralize acid in the
stomach, prevent
burning intestine
Both an exocrine and an endocrine organ
Exocrine: produces some enzymatic substance
Endocrine: produces hormones
PANCREAS
Hormone in pancreas
insulin
-secreted when blood sugar
concentration is high
-causes liver and muscles to
take up and store excess
glucose as glycogen
-promotes synthesis of
protein
glucagon
-secreted when blood sugar
concentration is low
-causes liver and muscles to
break down glycogen into
glucose
-stop protein and fat
synthesis
Small intestine
DUODENUM:
-first 10 inches of the small intestine
-in the duodenum, enzymes from
the pancreas enter and help
chemical digestions of all 3 kinds of
food-protein, fat, carbohydrates
-bile enters the duodenum from the
gall bladder and emulsifies fats
-duodenal wall produces hormones,
secretin and CCK
•Secretin stimulates the release of
pancreatic juice from the pancreas
•CCK stimulates the release of bile
from the gall bladder
Villi:
-final digestion of food takes place in the
small intestine
-site of absorption of nutrients through the
villi
-small intestine is specialized for absorption
of nutrients
-it is very long with convoluted walls which
increases surface area (more surface area
means more surface for absorption)
-walls have villi along the wall
-within each villus are small blood vessels
and a small lymph vessel called a lacteal
-the lacteal absorbs fluids and returns it to
the vein
Chemical digestion
Small intestine secrets maltase and peptidase
As in duodenum trypsin
converts protein into
peptides
-peptidase: break down
peptides into amino
acids
peptidase
Peptides +water 
amino acid
As in duodenum
pancreatic amylase
changes starch into
maltose
-maltase: converts
maltose to glucose
maltase
Maltose + water  2
glucoses
maltase, peptidase work better in a basic pH
Fatty acid and 3 glycerol are absorbed into
lacteal
Amino acid and glucose enter the blood
vessel in villi
a double layer of peritoneum that attaches to the back wall of the
abdominal cavity and supports the small intestines
MESENTERY
WE HAVE FINISHED THE
FOURTH DAY TRIP , YEP!!!!
DAY FIVE
IT IS THE LAST DAY OF OUR TRIP
LARGE INTESTINES
Include:
4 colons –reabsorb the water in the remains
and some mineral and vitamin
-ascending colon
-transverse colon
-descending colon
-sigmoid colon (enter rectum)
Appendix:
-junction of the small and large intestine
-help against infection
Pelvic cavity
• Rectum
-enlarge portion of the
colon
-store undigested food
temporarily
• Anus
-also named “anal
sphincter”
-bands of muscle which
allow undigested
waste to exist the
body in the form of
feces
Elimination:
All contents of food that cannot be digested exist
the body by the process of elimination or defecation
E.Coli Bacteria
• In large intestine
• Consume any substance that
were not digested earlier
• When the bacteria break
down these substances, they
gives of odorous molecules
that cause the characteristic
odor of feces, or “passing
gas”
Tips
• If you want to buy
some postcard, you’d
better buy some
before we go out the
final door, once we
come out, Ms. Win
will collect your
passport and you
cannot go back again.
Finally, finally we come out …
Thank you, MR. Bass for your
contribution to this trip
Bibliography
Chemical Digestion PPT
Images:
www.bing.com
http://www.bing.com/images/search?q=pancreas&FORM=HDRSC2
http://www.bing.com/images/search?q=e.coli&go=&qs=n&form=QBIR&pq=e.coli
&sc=8&sp=1&sk=#view=detail&id=36A8462F8ECC891C695424C5815C9A1189
892D97&selectedIndex=0