4th Class General Knowledge Our Body Our Body and Health

Our Body and Health

Category : 4th Class

Our Body and Health


Interesting Facts

  •             Your mouth produces about one litre of saliva each day!
  •             A cell takes 24 hours to form and then divide to form new cells.



Our body is made up of cells. Cells are the smallest unit of life. Cells, which are similar in structure and function, group together and perform a common function. These group of cells are called tissues. Accordingly, many similar tissues combine together and perform a common function called organ. Eyes, nose, heart, brain, lungs, skin etc., are different organs of the body.



1. Digestive system

Our body needs food to provide it with energy, vitamins, and minerals. The food is first broken down by the digestive system so nutrients can be released and used by our body for energy.


Do you know?

  •           The small intestine is the longest section of digestive tract
  •            Lungs are the only human organ that can float in water.
  •            Woman and children breathe at a faster rate than men.
  •           The small intestine is about 22 feet long. And about an inch in diameter.

2. Respiratory system

We take in air mostly through our nose, and then passes through the wind pipe into the lungs. The air we take in is called inhaled air. It is rich in oxygen. And the air, which is expelled from the lungs outside our body is called exhaled air, which is rich in carbon dioxide. This whole process of inhaling and exhaling of air is called respiration and the organs involved in the process are called respiratory organs. Breathing system can be simply represented as:


3. Skeletal system

All the bones together form the skeletal system. Bones protect the soft organs of the body. Skeletal system is the framework of the bones. It gives proper shape strength and rigidity to the body. Femur bone is the longest bone is the smallest bone of the human body is present in ear. There are 206 bones in the body. Joints fastens two or more bones together. Joints allow body to move in a particular direction.


4. Muscular system

Muscles constitutes more than half of the body. Muscles are attached to the bones and help in providing movement to the body. All the muscles together form the muscular system of the body. Muscles work by expanding and contracting. We can show happiness, sadness, anger on our face muscles. Legs and arms muscles get shorten and lengthen to bring movements. There are more than 650 muscles in our body.


Do you know?

  •            The nervous system helps different parts of our body to communicate and allows our brain to control what is going on.


5. Nervous system

The nervous system is made up of the brain, the spinal cord, and a large network of nerves that covers all parts of the body.

Coordination and Cooperation between Brain and Body

Everyday our body performs a lot of functions. Brain is at the centre of all the activities. Brain only tells us what to do or what not to do. For example, in the process of walking, brain just orders the related organ to move. Muscles which are involved in waking get active and perform walking.

Our eyes see a rose flower. This message reaches brain through a network of cells called nerves. Brain interprets the information and tells the eyes that it is a rose flower. The nerves act like messenger. Spinal cord connects all the parts of the body to the brain. Skull protects brain and backbone protects spinal cord from injury.

When finger touches the hot plate, receptor receives the information and sends it to brain through nerves. Brain analyzes the situation and orders the related muscles to remove the finger. This all happens in fraction of a second. This is how body performs function under the guidance of the brain.


6. Circulator system

The heart, the blood and the blood vessels constitutes the circulatory system. Blood is an important part of the body because it contains vital nutrients and oxygen to burn food and produce energy for the body to live. Blood has to reach to all the cells of the body. This work is performed by the heart. Heart behaves like pumping organ. It pumps blood to all the parts of the body through a network of blood vessels, which is actually thin tube-like structure. Heart is made up of muscles only and works non-stop. To do any heavy work or exercise, body requires more energy. Therefore, heart pumps blood faster to meet the demand. That is why, when we run, we feel our heart beating gets faster. When we rest, our heart beats about 72 times a minute.



7. Excretory system

Our body has a filtering system, called the excretory system. This system filters the blood to remove wastes that could be harmful to the body. There are four main parts that make up the excretory system: the kidney, ureters, bladder and urethra. Kidney filters excess water and. ammonia from the blood and make the blood pure. These unwanted substances are urine which is excreted or removed outside the body through the urinary bladder. Similarly our skin removes unwanted substance from the body in the form of sweat. 


Do you know?

  •            Eggs contain the highest quality of food protein.
  •            All parts of an egg are edible, including the shell, which has a high calcium content.



8. Reproductive System

Living organism produces offspring of its own kind to increase its number and to maintain the balance in the nature. Reproductive system performs the process of reproduction. Reproductive system is very essential for new life.



            Your food essentially contains five main nutrients.

            Nutrients are those components in food that we require to survive and grow.




1. Energy giving food      

Food we eat

Your food essentially contains five main nutrients. Nutrients are those components in food that we require to survive and grow.

Energy giving foods contain two main components, carbohydrates and fats.

Function: Carbohydrates provide instant energy to us.


Sources: Bread, rice, fruits, whole grains, etc.

Healthy suggestion: Carbohydrates are also present in chocolate and soft drinks, but they are bad for your teeth. Hence, it is better to eat natural sources of carbohydrates.

Functions: Fats are stored in our body and give energy to the body when required.

Sources: Meat, vegetable oil, butter, dry fruits, etc.

Healthy suggestion: Fat is essential for your body, but eating excess of fatty foods is harmful to the body and can lead to obesity.


2.       Body-building foods contain proteins.

Functions: Body-building foods are required for muscle building, repairing of worn-out tissues.

Sources: Chicken, fish, eggs, pulses, soya bean, mushroom, milk, etc.

Healthy suggestion: Growing children need more protein- rich food. It helps in the growth of their body and helps to build strong muscles.


3.       Protective Food

Protective foods contain two main components: vitamins and minerals.

Functions: Vitamins are needed for proper functioning of our body. It is needed to keep our body fit and increase our ability to fight with germs. There are 13 different type of vitamins

Sources: Fruits, green leafy vegetables, fish, etc.


Healthy suggestion: Our body needs vitamins in frequent and small doses.

Functions: Minerals keep our body healthy. They strengthen our bones and help in the growth and development of the body.

Sources: Milk, meat, vegetables, pulses, etc.

Healthy suggestion: Salt is a mineral that is required by our body in small amounts every day.


Balanced Diet

A diet that contains the proper proportions of carbohydrates, fats, proteins, vitamins, minerals and water to maintain good health is called balanced diet.




                 Cleaning the Raw Food

Fruits and vegetables are grown in fields, they have dust and mud stuck on them. These dust particles carry germs along with them. These foods are also sprayed with chemicals to protect them from insects. These germs and chemicals are harmful to us. Therefore, we must wash fruits and vegetables thoroughly before cutting them. If they are washed after cutting, some of their nutrients might be lost.


Precautions While Cooking

Fruits and some vegetables like cucumber, radish and carrots can be eaten raw. However, most of the vegetables have to be cooked before eating. You have learnt about different methods of cooking food like boiling, steaming, frying, roasting, and baking. Some precautions that need to be taken while cooking food are:


  •        Food should not be cooked for too long. It can destroy its nutritional values.
  •        Food should be cooked in just enough water. If the extra water is thrown away, the nutrients present in it will also be lost.
  •        The vessel should be covered while cooking food to save fuel.



Preserving Food

You must have seen that your mother keeps many food items in the refrigerator. Have you ever thought why? When food is kept out for a very long time it gets spoilt. It smells bad and this is due to germs and molds than grow on them and spoil the food. The perfect condition for food spoilage is warm temperature and presence on moisture. Food exposed to air for long hours gets spoiled due to the growth of microorganisms. You may fall sic« after eating such food. It can be prevented in man) ways. The process of preventing food spoilage is known as preservation of food. Jams, jellies, pickles, sauce, etc. are preserved food items. Some of the methods of food preservation are:                                 



Life is very precious to all of us. But at times we may endanger our lives by accident. Accident is an undesirable phenomena and it may occur anywhere, anytime. But many times, accidents occur because of our negligence. Such accidents can be prevented by following certain safety rules, outside and inside our houses.


1.         Safety Measures to be followed outside the House

  •             Always follow the traffic rules while moving on the road.
  •             Always walk to the left side of the road. If there is pavement, walk on it. 
  •             Always cross the road at the zebra crossing to avoid accidents. First look to the right and left and then cross the road.
  •             Never play near or on the road. 
  •             Always give signal with your hand before turning, if riding a bicycle or rickshaw.
  •            Never pick up any unattended articles, if you see any. In form to the nearest police station.

 2.         Safety Measures at School

  •             Climb up and down the stairs carefully without pushing anyone.
  •             Don't run on the corridors.
  •            Always follow lab rules while doing experiments in the lab.
  •            Never play or run in the classroom as one may get hurt while hitting the desks or benches.   
  •            Don't throw wastes on the floor as anyone may step on it and fall on the floor.
  •            Never insert fingers in the socket of the electric switch board.


3.         Safety Measures inside the House

  •            Never touch any electrical appliances or switch boards with wet hands. You may get fatal shock.
  •             Use sharp cutting instruments like knives, scissors, blades, etc., with care and protection.
  •            Always switch off the knob of the gas cylinder, if it is not in use.
  •              Do not run on the wet floor. You may slip and fall on the floor.
  •            Never play with matchsticks.
  •            Walk carefully on the wet floors of both room etc.



First aid is the immediate treatment given to an ill or injured person before regular medical aid can be obtained. In this chapter, we'll learn about the type of first aid, which should be provided to the injured person, in different situations.


1.    First aid in case of fracture: Do not let the affected area to move. Support the injured portion with stick and clothes in a comfortable position. Take the Patient to the hospital as soon as possible.


2.    First aid in case of burn: Wash the burn part with clean water. Antibiotic cream can be applied over the affected area. Light dressing can be done if the injury not serious. If the injury is due to any chemical, pour maximum possible amount of water to remove chemicals from the burnt area. Take the patient to the doctor.


3.    First aid in case of nose bleeding: Do not get panic. The patient lie down in an easy position, keeping the head downwards.

It would stop bleeding. If bleeding doesn't stop. Then old the nose between the thumb and the finger for 5-10 minutes. Ice can be applied over the nose. During the whole process ask the injured person to breathe through the mouth. If not cured take the patient to the concerned doctor.


4.  First aid in case of insect bite: Wash the infected area with detol and try to remove the sting with the help of sterilized needle Apply basic medium like baking soda or toothpaste over the affected area, if it is bee sting.  Which is acidic. Wasp sting is basic, so apply weak acid like vinegar, which is easily available. It will neutralize the effect. Take the patient to the doctor, if the injured person is not getting relief.


5.  First aid in case of drowning: Lie down the patient sterilized needle with flat on stomach and face, on side position.

Press the stomach to expel extra water from his/her body. Give artificial respiration, remove wet clothes and cover the body with blanket. Give hot coffee and tea to the patient on regaining consciousness.



In order to avoid loss and serious infection from injury, we should give first aid to the injured person. For that, every school and house should have a box containing necessary first-aid kid, that is, cotton, bandages, scissor, Detol. anife, antiseptic cream, magnifying glass, torch, etc.   

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