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? When you eat ice-cream, where does it go? Is it magic that makes the ice-cream Is it magic that makes the ice-cream disappear?disappear?

• Mum and Dad maybe tell you that the food Mum and Dad maybe tell you that the food you eat is absorbed by your body, but how?you eat is absorbed by your body, but how?

• People usually say that our stomachs help us People usually say that our stomachs help us digest food, but does all the food become digest food, but does all the food become little molecule only in the stomach?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)

NOW, PACK YOUR THINGS AND LET’S START THIS AMAZING TRIP

Let’s do this

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

• Mouth: receive food, is bounded externally by the lips and cheeks.

• Start digestion of starch • Includes:1. Hard palate2. Soft palate3. Teeth4. Tongue5. lip

Today, we will start our trip to have a comprehensive look at oral cavity

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　Ｓｔａｒｃｈ ++　ｗａｔｅｒ－－＞　ｍａｌｔｏｓ　ｗａｔｅｒ－－＞　ｍａｌｔｏｓｅｅ

Ｓａｌｉｖａｒｙ　ａｍｙｌａｓｅ

Salivary amylase works better in a neutral pH condition

DAY ONE’S CONCLUSION

There are both physical and chemical digestions happen in our mouth.

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 SphincterWhen 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.

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.

Some extra note:

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• In stomach, protein digestion starts

pepsin

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

WARNING

DO NOT STAND NEAR THE GASTRIC GLANDS!!!!!!!!!!!!!

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 FourWe 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

EMUSIFIERBile 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:

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

-produces digestive enzymes and sodium bicarbonate

-pancreatic juice:

•Pancreatic amylase, trypsin, lipase and sodium bicarbonate

•Secreted into the duodenum via the pancreatic duct

PANCREAS

Both an exocrine and an endocrine organ

Exocrine: produces some enzymatic substance

Endocrine: produces hormones

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

As in duodenum trypsin converts protein into peptides

-peptidase: break down peptides into amino acids

Peptides +water amino acid

As in duodenum pancreatic amylase changes starch into maltose

-maltase: converts maltose to glucose

Maltose + water 2 glucoses

Small intestine secrets maltase and peptidase

peptidase maltase

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

MESENTERY

a double layer of peritoneum that attaches to the back wall of the abdominal cavity and supports the small intestines

WE HAVE FINISHED THE FOURTH DAY TRIP , YEP!!!!

DAY FIVEIT IS THE LAST DAY OF OUR TRIP

LARGE INTESTINESInclude:

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

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