CRITICISM CLASS CLASS 9 TOPIC

1. BREATHING FOR ENERGY

2. BREATHING
Breathing means taking in air rich in
oxygen and giving out air rich in carbon
dioxide with the help of respiratory
organs.

3. PARTS OF HUMAN RESPIRATORY SYSTEM

4.  NOSTRIL : An opening through which air passes in and out of the body.
 NASAL CAVITY : The cavity which connects the nostrils with the pharynx
 TRACHEA : A long tube by C shaped cartilaginous ring
 BRONCHUS : Branches of trachea which enter the lungs.
 BRONCHIOLE : The terminal branches of bronchi that open to alveoli.
 ALVEOLI : Delicate air sacs, elastic in nature, seen at the tip of bronchioles. The exchange of
gases takes place here.
 DIAPHRAGM : The muscular wall that separates the thoracic and abdominal cavity.

5. ACTIVITY 1

6. ATMOSPHERIC AIR INTO LUNGS
 Breathing is a process that take place without our knowledge,
during which air is taken in and expelled.
 Act of breathing air into the lungs is called INHALATION.
 Act of letting air out of lungs is called EXHALATION.
 There is a rhythemic expansion and contraction occurs on the
thoracic cavity during respiratory movement.

7.  With the increase in size of the thoracic cavity, air enters
the lungs. This is called inspiration.
 As a result of the contraction of the thoracic cavity, air is
expelled from the lungs. This is called expiration.
 The combining works of intercoastal muscles and the
diaphragm help in increasing and decreasing the volume
of thoracic cavity.

8. RESPIRATORY MOVEMENTS

9. ACTIVITY 2

10. THANK YOU