THE HUMAN BODY
The body and Its Functions
The human body is made up of bones, blood, nerves and muscles. The outer covering of the body is the skin. The body consists of different kinds of cells. A number of cells join together to make a tissue. A number of tissues together from an organ. Organs are external as well as internal.
External Organs
The external organs are eyes, ears, nose, tongue and skin. We can see these organs.
Theses external organs are our sense organs. Sense organs are important to us because they tell us about our surroundings. Stand in front of a mirror. Observe your body parts. These body parts can be grouped as follows:
1. Head: Turn your head sideways. Raise your head up and down. You can do these movements due to the neck. Note the other features of your head and their functions.
2. Neck: The neck rests on the shoulders. Below the shoulders lies the chest, stomach, waist, back and hips. When you have to pick up a fallen pencil, you bend at your waist. We can bend in front, sideways and little to our back.
3. Arms and legs: Every human being has similar body parts. Yet, we look different from one another. Why? The shape and size of the body parts differ from person to person. This makes us look different from one another. Thus, even in a crowded room, you can spot your friends easily. The differences in external body features, the height and build of the body make us different from one another. These differences help us to recognize one another.
Internal organs
We have a number of internal organs. We cannot see these organs. However, these organs help the body to functions smooth and keep us healthy and alive. The internal organs are brain, lungs, heart, liver, stomach, small and large intestines, bladder and kidneys.
A. The Brain:
The brain lies in the skull or head. The brain is the control center of the body. It receives messages from all parts of the body, understands and sends a reply message.
B. The Lungs:
The two lungs lie in the chest cavity. They are protected by the ribcage. The lungs help us to breathe.
C. The Heart:
The heart lies between the two lungs. The heart is the pumping station of the bloody supply. It supplies blood to the whole body. Your heart is the size of your fist.
D. The Liver:
The liver is the largest gland in the body. It lies in the upper right abdomen. The liver stores food. It purifies blood. It also helps in the digestion of food.
E. The Stomach
The stomach lies in the upper abdomen. Food that is eaten goes in to the stomach and remains there for 3-4 hours. The stomach helps to digest the food.
F. The Bladder and Kidneys:
These organs lie in the lower abdomen. The kidney is a bean-shaped organ. The two kidneys lie on each side of the spine in the lower parts of the back. The kidneys purify the blood by removing the waste matter from it. The bladder is a muscular organ that stores urine before expelling it from the body. A group of organs work together to form a system.The human body is made of bones, blood, nerves and muscles.
SENSE ORGANS AND THEIR CARE
Organs which help us to see, hear, smell, taste and feel are called sense organs. The organs which help us to know the world around us are eyes, ears,nose, tongue and skin. Sense organs are connected to the brain through nerves. Sense organs send messages to the brain. The brain responds to these messages and thus we know about the things around us.
1. Sense of Sight
The eyes can see things around us. We learn about shape, size and color of an object by looking at it.
2. Sense of Sound or Hearing
We hear different sounds through our ears. We learn the sounds of different things. Some sounds like music are pleasing and soothing. Other sounds like banging and screaming are loud and harsh. There are things like thunder which
- Cannot be see. Yet we hear the sound of thunder.
3. Sense of Smell
Smells are of many different kinds. Our nose picks up these smells and the brain tell us about it. Some tells us about it. Some smells are good. We like the smell of flower or food. If it is the smell of garbage we do not like it. We cover our nose to keep out the foul smell. The nose performs another important function which is breathing. It helps us to stay alive.
4. Sense of Taste
Taste-buds on the tongue tell us about the different tastes. There are four basic tastes-sweet, salty, sour and bitter.
5. Sense of Touch or Feel
The skin gives us a sense of touch and feel our finger tips are the most sensitive parts of our body. Lips, too, are very sensitive. Sense of touch helps us to know hot or cold, soft or hard and rough or smooth things.
Care of the Sense Organs
We must look after and take proper care or our sense organs.
We should keep our sense organs clean and protect them from damage.
1. The Eyes:
a. Eyes are the most delicate organs. We should be careful to protect the eyes from injury.
b. We should wash our eyes daily with fresh,and clean water.
c. We should not rub or touch the eyes with dirty fingers or a dirty hand kerchief.
d. Always study or read in proper light.
2. The Ears:
a. We should not clean the ears with any sharp or pointed object. This could damage the eardrum.
b. We should cover our ears if there is very loud sound.
3. The Nose:
a. When you wash your face every morning blow your nose to clean it.
b. Always use a clean tissue paper or a handkerchief to clean your nose.
4. The Tongue:
a. We should clean our tongue every morning when we brush our teeth.
5. The Skin:
Care of the body is care of the skin.
a. Clean every part of your body while taking a bath.
b. Dry your body with a clean towel before you wear fresh clean clothes.
c. Change undergarments daily.
I. Tick the correct answer.
a. Animals that live in water are called
Terrestrial animals Aquatic animals Arboreal animals
b. Which of these does not need to be cooked before eating?
potato cauliflower apple
c. Vitamins and minerals are called
Protective food Body building food Energy-giving food
d. Animals that eat both plants and animals are called
omnivores herbivores carnivores
II. Put ‘√’ for the True and ‘ x’ for the False statements.
1. Fishes breathe through gills.
2. Plant eating animals are called herbivores.
3. Vegetables should be washed before cutting.
4. Birds do not have hollow bones.
III. Name the following.
1. Nutrient present in butter, oil, cheese etc. ________________________________________
2. The polar bear is adapted to live in _____________________________________________
3. The yellow portion of the egg is called __________________________________________
IV. Look at the picture and complete the life cycle of the given animals.
V. Underline the correct answer.
1. Porcupines have (spines / fur) for protection.
2. Birds (lay eggs / give birth to babies).
3. Shedding of old skin is called (moulting / camouflage).
Please click on below link to download CBSE Class 4 Science Worksheet Set A
