Aarti PandeyBed 2010-2011

Roll no.90Subject: Science

Topic: Human Digestive System

Definitions and ConceptsDefinitions and Concepts

• Organ—a structure made up of two or more kinds of tissues organized in such a way that they can together perform a more complex function than can any tissue alone

• Organ system—a group of organs arranged in such a way that they can together perform a more complex function than can any organ alone

Human Digestive System

How is food digested?

Digestion involves:

• Breaking down of food into smaller pieces

• The mixing of food

• Movement through the digestive tract

• Chemical breakdown of the large molecules of food into smaller molecules

Organs of Digestion and there Functions

Mouth

• Teeth bite off and chew food into a soft pulp that is easy to swallow.

• Chewing mixes the food with saliva, from salivary glands around the mouth and face, to make it moist and easy to swallow.

Mouth

• Enzymes in the saliva begin digestion of carbohydrates.

Esophagus

• The esophagus is a muscular tube. It takes food from the throat and pushes it down through the neck, and into the stomach.

• It moves food by waves of muscle contraction called peristalsis.

Stomach

• The stomach has thick muscles in its wall. These contract to mash the food into a water soup called chyme.

• The stomach lining produces strong digestive juices.

Stomach

• These create chemical reactions in the stomach, breaking down and dissolving its nutrients.

Small Intestine

• This part of the digestive tract is narrow, but very long - about 20 feet.

• Enzymes continue

the chemical reactions

on the food.

Small Intestine

• The nutrients are broken down small enough to pass through the lining of the small intestine, and into the blood (diffusion).

• Nutrients are carried away to the liver and other body parts to be processed, stored and distributed.

Large Intestine

• Useful substances that were not absorbed in the small intestine, such as spare water and body minerals, are absorbed through the walls of the large intestine, back into the blood

• The remains are

formed into brown,

semi-solid feces, ready

to be removed from the body

Rectum and Anus

• The end of the large intestine and the next part of the tract, the rectum, store the feces.

• Feces are finally squeezed through a ring of muscle, the anus, and out of the body.

Pancreas

• The pancreas, like the stomach, makes digestive juices called enzymes which help to digest food further as it enters the small intestines.

Gall Bladder

• A small baglike part under the liver.

• It stores a fluid called bile, which is made in the liver. • As food from a meal enters the small intestine, bile flows from the gall bladder along the bile duct into the intestine.

• It helps to digest fatty foods and also contains wastes for removal.

Liver

• Blood from the intestines enters to the liver, carrying nutrients, vitamins and minerals, and other products from digestion.• The liver is like a food-processing factory with more than 200 different jobs. It stores some nutrients, changes them from one form to

another, and releases them into the blood according to the activities and needs of the body.

Identify the organs of digestive system

Q.1.Name some organ system in the human

body

Q.2. Name the organs of the digestive

system.

Q.3. Match the following:

Digestive system shape of digestive

organs

Stomach

Small intestine

Large intestine

Coil like part

Part with bulges on the

outside

Bag like part

Nasal Passage

Bronchiole

Alveoli

Pharynx

Trachea

Bronchi

Human Respiratory System Diagram

Oxygen CellHi I am O2 ,you can call me oxygen, and I will be your guide today.

I advise you keep all feet and hands inside the ride at all times.

JH

You may be asking, what is the Respiratory system? Well, the Respiratory system is the system that helps you breath in and out, so oxygen (02) can be pumped through your body and carbon dioxide (CO2) can be removed from the blood stream. You must remember that the Respiratory system is made up of many different organs.

JH

Where are we?

Nasal Passage

Bronchi Tubes

Alveoli (air-sacs)

Thin-walled blood vessels called capillaries

Very thin cells line the alveoli so that O2 and CO2 can pass in and out of the blood.

Bronchioles pass air to and from your alveoli.

The Trachea is held open by partial rings of cartilage.

Tongue

PharynxHere We Go!!!

JH

Here is a overview picture of the Respiratory System.

Just go to the next slide to seeit.

Picture Intro

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Respiratory Overview Picture

Nasal Cavity

Nose

Mouth

Bronchus

Bronchiole

Alveolus

Diaphragm

Throat

(pharynx)

Windpipe (Trachea)

Left lungs

Ribs

MB

Welcome

Now we will begin our tour.

Welcome to…

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This is where it all begins. This is where the oxygen first

enters your body and also where Carbon Dioxide leaves.

The Nose and Mouth

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The Nose and MouthWhen the air comes into your nose it gets

filtered by tiny hairs and it is moistened by the mucus that is in your nose.

Your sinuses also help out with your Respiratory System. They help to moisten

and heat the air that you breath.

Air can also get into your body through yourmouth/oral cavity but air is not filtered as

much when it enters in through your mouth.

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Nose and Mouth Picture

Nasal Cavity

Nostril

Oral CavityPharynx

Here is a picture of your nasal and oral cavity.

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The Pharynx and Trachea

Next we will head down to your pharynx(throat) and your trachea (windpipe).This is where the air passes from your

nose to your bronchi tubes and lungs.

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The Bronchi Tubes and Bronchiole

These bronchi tubes split up, like tree branches, and get smaller and smaller

inside your lungs.

The air flows past your bronchi tubesand into your bronchiole. These tubes

keep getting smaller and smaller until theyfinally end with small air sacs (called alveoli).

But we will go there later…

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The Pharynx and Trachea

Your pharynx (throat) gathers air after it passes through your nose and then the air is passed down to

your trachea (windpipe).

Your trachea is held open by “incomplete ringsof cartilage.” Without these rings your trachea might close off and air would not be able to get

to and from your lungs. MB

Pharynx

(Throat)

Mouth

Trachea

Your trachea (windpipe) splits up into two bronchi tubes. These two tubes keep

splitting up and form your bronchiole.

The Bronchi Tubes and Bronchiole Intro

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Alveoli and Bronchi Picture

Trachea

Bronchi Tubes

Bronchiole

Alveoli

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The Alveoli and Capillary Network

Your alveoli are tiny air sacsthat fill up with air/oxygen when you

breath in.

Your alveoli are surrounded bymany tiny blood vessels called

capillaries.

The walls of your alveoli (and capillaries) are so thin that the oxygen or carbon dioxide can

pass through them, traveling right into, orout of your blood stream.

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Alveoli Picture

Here is a closeup picture ofyour Alveoli

and a Capillarysurrounding it.

Capillary

Red Blood Cell

Oxygen is picked up

Carbon Dioxide is dropped off

Wall of the air sac

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Alveolus

Bronchiole

Respiratory Bronchiole

Alveolar Duct

Alveolar Sac

Capillaries

JH

Intro to

Diaphragm

Now we will look at the Diaphragm. You might be wondering, what does the Diaphragm do?

The Diaphragm is an important factor in breathing.

JH

Diagram of Diaphragm

JH

Experiment Instructions

1st you need a bottle that you can sacrifice to cut up.

2nd you cut the bottom of the bottle and put a big balloon on the bottom.

3rd get a rubber cork ( make sure it blocks the hole)and put a hole through it ( top to bottom). Insert a thin tube into the

cork and place a balloon on the bottom of the tube.

4th make sure the thing is airtight.

JH

Here is an experiment that you can try. Diaphragm Experiment

JH

Q.1. Which organs help in the function of

respiration?

Q.2. Find the odd-man-out:

diaphragm, pancreas, alveoli, trachea.

THANK YOU