The document outlines the structure and function of the respiratory system. It identifies the major organs that make up the system, including the nose, pharynx, larynx, trachea, bronchi, bronchioles and lungs. Gas exchange occurs in the alveoli of the lungs, where oxygen passes into the blood and carbon dioxide passes out. The conducting passageways warm, humidify and filter the air before it reaches the lungs. The respiratory system is essential for bringing oxygen into the body and removing carbon dioxide.

2. OBJECTIVE
S OF THE
LESSON:
Identify the structure and function of
respiratory system.
Explain how gas exchange happen inside
the body.
Acknowledge the importance of
respiratory system in bringing a purified
air as it moves into the lungs where
oxygen is distributed in different parts of
the body.

3.  The organs of the
respiratory system include
the nose, pharynx, larynx,
trachea, bronchi and their
smaller branches, and lungs,
which contain the alveoli.

4.  Alveoli or air sacs are the only respiratory sites where gas
exchange occurs;
Conducting passageways, which allows air to reach the
lungs. These passageways also purify, humidify, and
warm the air that reaches the lungs.

5. Nose
Pharynx
Larynx
Trachea
Bronchus/Bronchi
Bronchioles
Alveoli
Conducting
passageways
Exchange of gas
Note: Trachea, Bronchi, Bronchioles, and
Alveoli are parts of the Lungs

6. 1. NOSE - is the only visible part of the respiratory system.
a. Nostrils or external nares (openings that allow outside air to flow)
b. Anterior nasal passage (contains nasal hair that traps foreign particles)
c. Nasal Cavity (nasal septum, olfactory receptor, mucous glands, conchae)
PURPOSE:
Serves as entrance and filters particles that will enter
the lungs and moistens the air that prevents dryness
in the respiratory membranes.

7. Q1: WHY DOES
THE AIR WE
BREATHE
NEEDS TO BE
FILTERED
BEFORE IT
REACHES THE
LUNGS?

8. BREATHE
NEEDS TO BE
FILTERED
BEFORE IT
REACHES THE
LUNGS?
If the air will not be filtered in the respiratory
tract or passageways, it will cause
complications in the respiratory organs.

9. The Olfactory System
-is responsible for our
sense of smell. This
sense, also known as
olfaction, is one of
our five main
senses and involves
the detection and
identification of
molecules in the air.
Nasal Cavity

10. 2. Pharynx (Throat)
- directs air from the nose and mouth to
the larynx.
Three regions in the pharynx:
a. Nasopharynx - receives air
from the nasal cavity.
b. Oropharynx - passageway for
food and air.
c. Laryngopharynx - leads to
another respiratory tract.
Tonsils, are clusters of tissue that
protect the body from foreign invaders.

11. 3. Larynx (Voice box), plays a role in speech. It is formed by
cartilages.
 The largest cartilage is the shield-shaped thyroid cartilage,
which forms a protuberance commonly known as the “Adam’s
Apple”.

12. 3. Larynx (Voice box) directs air from the pharynx to the
trachea and contains vocal cords for vocalization.
-Epiglottis, is a cartilage that guards the opening of the
larynx from anything rather than air to prevent it from
reaching the lungs. (covers the upper part of larynx that
prevents food from entering the lungs)

13. Vocal folds or true vocal cords, are folds of membrane that
are located in the larynx.
 These membranes vibrate when air is expelled and allow a
person to speak.

14. 4. Trachea (windpipe) connects larynx to the bronchi;
splits into left and right bronchi that direct air to the left
and right lungs.
-Cilia (keeps the airways clear of mucus and dirt,
allowing us to breathe easily and without irritation).

15. 5. Bronchi are
extensions of the
windpipe.
 The air that passes into
the bronchi is already
warm, humidified, and
most likely free from
most impurities.
-Bronchioles (smaller
bronchial tubes within
the lungs that direct air
to small air sacs known
as alveoli)

16. 6. Alveoli is the functional unit inside the
lungs; bronchiole terminal sacs (alveolar sac)
that are surrounded by capillaries and are the
respiratory surfaces of the lungs.
An alveolar sac is a common air
space at the end of an alveolar
duct. It opens into two or more
alveoli in the lungs. So the
alveoli are clustered around the
alveolar sacs.

17. Lungs, are paired organs in
the chest cavity that enable
gas exchange between the
blood and the air.
Parts of the lungs:
Apex, the upper part of the
lungs, whereas the inferior
border is the base (Figure
1.11) which rest on a dome-
shaped muscle called the
diaphragm (Figure 1.12).

18.  The right lung is shorter and wider than the left lung. It has
three lobes, whereas the left lung has two.
 The right lung consists of three lobes: the right upper lobe
(RUL), the right middle lobe (RML), and the right lower
lobe (RLL).
 The left lung consists of two lobes: the left upper lobe
(LUL) and the left lower lobe (LLL).
 Each lung is covered by a membrane called pleura,
produces slippery secretion called the pleural fluid which
allows the lungs to glide over the wall of the thorax during
breathing.

19. Lungs also contain smaller
branches of bronchi called
secondary, bronchioles and
tertiary bronchi,
bronchioles, and alveolar
ducts, which end in alveolar
sacs that contain alveoli (Figure
1.14).
Alveolus is the functional unit
of lungs.

21. If one part of the respiratory system fails to work, the rest
of the parts will not be able to work as well. Our body will
not be able to get oxygen and might lead to death if not
treated on time.

22. Organs of the respiratory system work together in bringing
clean oxygen into our lungs in which our body needs for
cellular process. This makes oxygen as one of the essential
elements for life. If one of these organs fails, the system
cannot function properly in bringing oxygen into our lungs
and may lead to some serious health problems.

23. FOLLOW-UP!
1. What are the conducting passageways of the
respiratory system?
2. What is the function of the air sacs?
3. How are impurities filtered filtered in the
respiratory tracts?

24. For 10 pts. :
Draw and label the
parts of Respiratory
System.

25.  Guide Questions :
1. What are the parts and functions of the respiratory system?
2. How does gas exchange occur?
 Application:
Body movements involved in doing simple chores, such as
watering plants: in the garden and sweeping the floor, can keep
your respiratory system in good shape. Perform other body
movements in an area with fresh air. You may do them with
background music. (Document yourself doing the exercise using
your camera/phone. The maximum time of the video is 2 mins.
and store it in a flash drive.)