The Human Body

For Class 3

Important Points on Human Body

• What are the five sense organs in our human body?
  Eyes: We see things around us with our eyes.
  Nose: We smell things around us with our nose.
  Ears: We hear what is happening around us with our ears.
  Tongue: We can taste things with our tongue.
  Skin: We can feel things around us with our skin.
• The skeletal system:
  206 bones present in our body are joined together to form skeleton. Skeleton protects all the soft organs inside our body. It also give our body its shape.
• The muscular system:
  Soft parts of our body are called muscles. Some muscles are attached to our bones. Muscles pull our bones to make them move.
• The digestive system:
  Digestion is the process of breaking down the food into very small pieces. After digestion the food are absorbed by the body to give energy. The group of organs which digest the food is called the digestive system.
• The breathing system:
  Nose, windpipe and lungs are parts of our breathing system. When we breathe air enters through our nose and passes through the wind pipe and enter the lungs. In the lungs, oxygen is absorbed from the air and enter the blood. Through blood, oxygen is taken to all parts of our body.
• The circulatory system:
  The heart, blood and blood vessels make up the circulatory system. The heart pumps blood to all parts of our body. The blood goes around our body in blood vessels.
• The excretory system:
  The lungs, kidneys and skin make up the excretory system. The excretory system helps to throw out waste material from our body in the form of urine and potty. Kidneys help to clean our blood. Skin helps to throw out excess water and salt in the form of sweat. When we breathe out carbon dioxide is thrown out of our body by lungs.
• The nervous system:
  Brain and nerves make up the nervous system. Brain controls all parts of our body. It send orders to all parts of our body by sending messages through nerves. Message from all parts of our body also comes to the brain through these nerves.

A. ANSWER THESE QUESTIONS.

1. Name five major organ systems in the human body.
   Show Answer
   
   The five major organ system in the human body are the skeletal system, the digestive system, the excretory system, the nervous system and the circulatory system.
2. Why brain is the most important organ in the body?
   Show Answer
   
   Brain orders each part of our body what to do by sending messages through our nerves. Since the brain controls our body therefore it is the most important organ in the body.
3. Why does the food you eat have to be digested?
   Show Answer
   
   For digestion the food has to be broken down into very small pieces. The food we eat have to be digested because after digestion the food can be absorbed by the body to give energy.
4. Name the five sense organs and its uses.
   Show Answer
   
   Five sense organ of human body are ears, eyes, nose, tongue and skin.
   Ears: We hear with our ears.
   Eyes: We see things with our eyes.
   Nose: We smell the things around us with our nose.
   Tongue: We taste things with our tongue.
   Skin: We feel things around us with our skin.
   

B. TRUE OR FALSE

1. Air enters the lungs through the ________.
2. The _______ pumps blood throughout the body.
3. The _______ keep our blood clean.
4. The _______ move the bones by pulling at them.
5. The brain and nerves form our _______ system.