Kids Learning Science

   

4th Standard Science Term - I

My Body

  I. Internal Organs  

There are some body parts such as eyes, nose ears, hands and legs that we can see.  Such parts are called external organs. 

There are some body parts such as stomach, lungs and heart that are inside our body.  We are unable to see them.  These body parts are called internal organs.

Let s learn more about these parts now.

  1. Brain  

Brain is an important organ of our body and it is protected by the skull.  It has three main parts namely:

1. Forebrain

2. Midbrain

3. Hindbrain

Brain is the commanding centre of our body and it helps us to think and perform various actions.  Every action that we do like moving our hands, sitting or walking is possible only because of our brain.

Do you Know?

The human brain weighs about 1.3 kg. 

  Let us Play  

Memory Chain - A Brain Game (Teacher led activity)

How to play?

1. Make students to sit in a circle.

2. Place a tray with picture cards of different body parts and an empty tray.

3. Now ask a student to pick a card and name the body part and put the card in the other tray.

4. Call the next student.  Ask him to pick another card and name the first and the second card.

5. Then ask the next student to pick a card and tell the name of the first two cards and the new card.

6. In the same way, ask all the students to take the cards one by one and tell the names in the previous cards and the name of the new card also.

  2. Lungs  

Lungs are a pair of spongy, sac-like organs located in the chest.  They help us to breathe.

• When we breathe in, we take in oxygen from air through the nose and pass it to the lungs.  So, the lungs expands (becomes large)

• When we breathe out, we give out carbon dioxide from the lungs through the nose into the air.  So, the lungs contract (becomes small).

  Let us Play  

Bigger and Smaller

(Teacher gives balloons to all the children)

Teacher : Blow the balloon... What do you see?

Students : It becomes bigger.

Teacher : Like this, when we breathe in, the lungs become bigger.  If you let the air out from the balloon, what will happen?

Students : The balloon becomes small.

Teacher : Yes, like this, when we breathe out air, the lungs become smaller.

The lungs act like two balloons inside our chest.  As we draw air into the breathing system, the lungs get bigger as they are filled with air.  When you breathe out, air is pushed out of the lungs and they get smaller.

  3. Stomach  

Stomach is a 'J' shaped bag found below the lungs.  It breaks down food items and gives us energy.  It contains special juice to digest food.

  4. Heart  

Our heart is the pumping organ.  It pumps blood to all parts of the body.  It lies in between the lungs almost in the centre of the chest.  It is made up of muscles.

  More to Know  

The heart beats about 72 times in a minute.

  Let us Make  

Stethoscope

Things we need : Flexible tube, Two small funnel, Duct tape, Medium-size balloon and Scissor.

Steps to construct :

1. Put the small end of  the funnel at both ends of the flexible tube tightly.

2. Tape the funnel and the tube using duct tape.

3. Inflate the balloon to stretch it out.

4. Let the air out and then cut the neck of the balloon.

5. Stretch the remaining part of the balloon tightly over the open end of the funnel, tape it in place.

6. Place one funnel end off the stethoscope on the heart and the other funnel end near your ear.

7. Can you listen to the sound of the heart?

  5. Kidneys  

We have two kidneys.  They are bean shaped organs.

The kidneys purify blood by filtering excess water and toxins.

  6. Bones and Muscles   

 

Our body is made up of bones and muscles.  Press your upper arms.  The portion that is hard to touch is the bone.  The portion that is soft to touch is the muscle.

The bones give us shape.  They are the frame for our body and allow us to jump, run or just lie down.  Bones also protect the internal parts of the body.

Muscles are the soft parts that cover our bones.  They help us to move different parts of our body by contracting or relaxing, like a rubber band.

In order to maintain healthy bones we need to have healthy food, such as milk, cheese and eggs.  For strong muscles, we need to exercise and stay active.

  Do you Know?  

Babies are born with 300 bones but by adulthood the number is reduced to 206.

Amazing Fact

17 muscles are functioning while smiling and 43 while frowning.

So smile and save your energy!

  Let us Take care  

If your care for your,

Brain                   -    Sleep for eight hours

Heart                   -    Avoid fatty food

Stomach              -    Eat healthy food on time

Kidney               -    Drink more water

Bone and Muscles -    Exercise regularly    

  Let us Do  

Muscle Activity : To know that our muscles send information to our brain.  

Things we need : Two large plastic cups, Large bag of rice or beans.

Activity

• Blindfold your partner.
• Have your partner hold one cup in each hand.
• Take the cups back and add a small amount of beans or rice to one cup.
• Return the cups to your partner.  Ask him whether they weigh more.
• If your partner says one is heavier, ask him which one?
• Here we understand that weight difference felt by the muscles was sent to the brain as message.

 

  II. Teeth  

  1. Teeth and its types  

The teeth are the hardest parts in our body.  They are helpful for cutting and chewing the food.  The teeth are found inside our mouth.

We develop two sets of teeth in our lifetime.

1. Milk teeth : The first set of teeth starts to develop from the age of six months.  They are called milk teeth and they are 20 in number.  At the age of 6 or 7 the second set of teeth grow after milk teeth fall.

2. Permanent Teeth : Second set of teeth are called permanent teeth.  There are four types of teeth : incisors, canines, premolars and molars.  If permanent teeth fall, we cannot grow one more set of teeth.  So, it is important to take care of our teeth.  There are 32 permanent teeth.

  2. Importance of Oral Health  

As we learnt, it is important to take care of our teeth and also our mouth.  If you do not care your mouth and teeth, you will have problems with eating and speaking.

  3. Healthy Mouth  

It is important to take care of our teeth and mouth.  Brushing teeth, eating healthy food and regular dental checkup keep us healthy.  We should brush our teeth twice a day.

  4. Foods for Healthy Mouth and Teeth  

• Take plenty of fruits, vegetables and dairy products.
• Drink water or milk instead of sugary juices.
• Eat candy, cake and ice cream as less as possible.

  5. Taking Care of Mouth and Teeth  

• Change toothbrush once in every three months.
• Avoid sticky food.
• Brush twice a day (After getting up and before going to bed).
• Rinse your mouth with water after you eat.

  6. Neem Toothbrush  

Researchers believe that use of neem toothbrushes is the reason behind the bright smiles and healthy teeth of Indian villagers.  Indians traditionally chew neem twigs to keep their gums and teeth healthy.

  III. Good Touch, Bad Touch and Don't Touch  

"Good touch" and "Bad touch" are the words most commonly used to explain what touch is okay and what is not okay.  This helps us to understand when to tell a trustworthy person about bad touch and ask for help.  "Good touch" is a touch that cares for us or makes us feel safe.  "Bad touch" is any touch that we don't want or makes us feel scare.  Let us learn how to keep ourself safe.

Activities related to good Touch

• Parents hug and kisses.
• Father pats you on the head.
• Friendly hugs by family members.
• Shaking hands.

Activities related to bad touch

• Touching the buttocks and other private parts.
• Hitting, slopping, pushing, pinching or kissing.
• Activities that make you feel scared or nervous or ashamed.
• Dirty talk and dirty pictures.

MY BODY IS MY OWN.  I never allow others to misuse it.

Never be afraid to shout and say "Don't touch me".

It is never your foult.

Students must be taught that offenders might approach with the following "Dirty Tricks"

• Your mother is admitted in the hospital.  So, I have come to take you there.
• Could you please accompany me and guide me to reach this address?
• Tempting you with gifts or money.
• Distracting you with the promise of sweets or food.
• Offering to play 'doctor game' and 'hide and seek' game trying to touch you under that pretext.
• Pretending to show great concern for you.

Safety tips every child should know :

• Tell everything to your parents especially to mother.
• Don't share address and phone numbers with strangers.
• Don't answer the phone or open the door without and adult's presence.
• Never eat anything you get from strangers.
• Have emergency telephone number.

For teacher / parents :

How to prevent sexual abuse and what and the signs of sexual abuse?

• Behaviour changes of the child to be watched.
• Depressed and withdrawn from their peer group.
• Moving away from a particular individual, excessive dependence, decline in learning and dominant behaviour.  
• Internet can cause adverse impact.