1. I. Objective
Describe the function of each part of the respiratory system.
II. Subject Matter
A. Function of the Different Parts of the Respiratory System
B. References:
PELC I.2.2
Into the Future 5, p. 19
C. Science Concept:
The functions of the different parts of the respiratory system are:
1. Nostrils – enables air to enter the nasal cavity
2. Pharynx – enables air from the nasal cavity to enter the trachea
3. Larynx – produces sounds
4. Trachea – enables air to get to the lungs
5. Bronchioles – allow for the exchange of oxygen and carbon dioxide
6. Lungs– filter and purifies air
D. Science Processes: observing, identifying
E. Materials: charts, activity sheet, illustration
III. Procedure
A. ENGAGE
1. Science Updates
Endoscopy means looking inside and typically refers to looking inside the body for
medical reasons using an endoscope, an instrument used to examine the interior of a
hollow organ or cavity of the body. Unlike most other medical imaging devices,
endoscopes are inserted directly into the organ. Endoscopy can also refer to using
a borescope in technical situations where direct line of-sight observation is not feasible.
2. Review
What are the parts of the respiratory system?
3. Science Vocabulary
bronchi bronchioles alveoli
4. Motivation
Show picture of the lungs.
What do you think is the function of the lungs in respiration?
B. EXPLORE

2.  Presentation
Using the diagram, pupils will identify the functions of each part of the respiratory
system.
a. Setting of standards to be followed in doing the activity
b. Group activity
C. EXPLAIN
 Analysis/Discussion
Group reporting
Answer the following questions
What enables air to enter the nasal cavity?
What is the role of the pharynx in the respiratory system?
What is the importance of the epiglottis in the respiratory system?
What is the function of the alveoli ?
What is the role of the lungs in the respiratory system?
 Concept Formation
What are the functions of the different parts of the respiratory system?
The functions of the different parts of the respiratory system are:
1. Nostrils – enables air to enter the nasal cavity
2. Pharynx – enables air from the nasal cavity to enter the trachea
3. Larynx – produces sounds
4. Trachea – enables air to get to the lungs
5. Bronchioles – allow for the exchange of oxygen and carbon
dioxide
6. Lungs – filter and purify air.
D. ELABORATE
 Application
Fill in the blanks with the correct answer. Choose your answer inside the box.
lungs alveoli windpipe or trachea pharynx
epiglottis bronchioles bronchial tubes nostrils

3. Respiration begins at the nose as air enters through the
_____________. Inside the nose are tiny hairs which filter the dust and germs
from the air. Mucus along the walls of the nose warm and moisten the air. That
is why at the end of the day, the inside of your nose becomes dirty.
Air goes down the ________________ . It serves as the passageway
for the both air and food. It leads to a long tube called
________________________. There is a little flap on the top of the trachea. It
is called ______________________. The epiglottis closes the windpipe when
one swallows food or liquids.
The trachea branches out into pipes called
_______________________ or bronchi. These lead to the lungs. The bronchi
further branch out into smaller tubes called ______________________. These
bronchioles look like the branches of a tree whose ends have balloonlike sacs
or bags. These sacks are filled with air giving the lungs a sponge like quality.
These sacks are called _________________. The __________________ are the
lightest organs in the body. It filters the air. The actual exchange of gases takes
place in the alveoli.
E. EVALUATE
Directions: Match the parts of the respiratory system in column A with its function in
column B. Write only the letter of your answer.
COLUMN A COLUMN B
1. nostrils A. closes when someone swallows food or drink
2. pharynx B. filter and purify air
3. epiglottis C. enables air to get to the lungs
4. trachea D. allow for the exchange of gases
5. lungs E. enables air to enter the trachea
F. enables air to enter the nasal cavity
IV. Assignment
Memorize the different parts and function of the respiratory system. Be ready to recite it
front of the class.
PL =