The respiratory system is made up of airways that collect and transport air through the nasal cavity, pharynx, larynx, trachea, bronchi and bronchioles to the lungs. The lungs are where gases like oxygen and carbon dioxide are exchanged between the air and blood through tiny sacs called alveoli. Respiration involves the rhythmic movement of the diaphragm and ribs to inhale air into the lungs during inspiration and exhale air during expiration, ensuring a continuous supply of oxygen to and removal of carbon dioxide from the body.

1. The respiratory system

2. Respiratory system
The respiratory system is made
up of:
 Airways: Tubes that collect
air. They are: nasal cavity,
pharynx, larynx, trachea,
bronchi and bronchioles.
 Lungs: These are where
gases are exchanged.

3. Questions
 Which gases are exchanged?
 What characteristics must air have when it
reaches the lungs?
 Is respiration the same as cellular
respiration? Why?

4. Airways
 Nasal cavity: Blood warms
the air. The mucosae start to
clean and moisten the air.
Clean, warm and moist.
 Pharynx: Tonsils, which
produce white blood cells.
 Larynx: Vocal cords. When
air passes through these
cords, they vibrate and emit
sounds.
 Vocal cord

5. Airways
 Trachea: Rings of cartilage.
Mucus and cilia.
 Bronchi and brochiolioles:
Each bronchus leads to a
lung. They split into smaller
tubes. These small tubes
lead to tiny sacs, called
alveoli

6. Lungs
 Elastic and sponge-like
organs.
 Right lung is made up of
three parts and left lung has
two lobes.
 The lungs are surrounded by
pleurae.
 Why is the left lung smaller?

7. Gas exchange

8. Gas exchange
 It takes place in the alveoli.
 Molecules pass from air to
the bloodstream by
difussion

9. Respiration
Inspiration and expiration

10. Inspiration
 The diaphragm moves down
and flattens.
 Ribs move up and out.
 The volume of chest cavity is
increasing

11. Expiration
 The diaphragm relaxes,
curves and move up.
 The ribs move down and in.
 The volume of chest cavity is
drecreasing.
 What reason does it chanche
breathing rhythm?