The document describes the human respiratory system and breathing mechanism. It outlines the key structures involved, including the nasal cavity, trachea, bronchi, bronchioles and alveoli. It explains that air is inhaled through the nose and travels through these structures to reach the alveoli in the lungs. The document also notes the role of the diaphragm and intercostal muscles in breathing by changing the pressure and volume of the thoracic cavity during inhalation and exhalation.

1. 3/20/2023 Chapter 1 Respiration
Topic 1.1(a)
HUMAN BREATHING
MECHANISM
Mekanisma Pernafasan Manusia

2. 3/20/2023 Chapter 1 Respiration
Students should be able to:
 1. Identify the structure of the human
respiratory system.
 2. Identify the structure of the lung.
 3. Describe the process of inhalation and
exhalation.
 4. Relate the changes of air pressure in the
thoracic cavity to inhalation and exhalation.
 5. Describe the breathing mechanism.

3. 3/20/2023 Chapter 1 Respiration
1.1a

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Human Respiratory System
 consists of
Lung
Ribs cage
Diaphragm
Intercostals muscles

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1. Breathing Organs
 Include …
Nasal cavity
Breathing channel
Lungs

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2. The Breathing Channel
 consists of …
Trachea
Bronchus
Bronchiole

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3. The Lungs
 consists of …

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The function of the nasal cavity is
to detect …
warm
moisten
filter fine particles

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The trachea …
 a channel which
branches into two.
Each branch is called
bronchus which enters
the lungs.
 Flows air into our body
through the nose /
mouth and then into
the bronchiole.

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Alveolus
 i. In the lungs, the
bronchus branches to
form many smaller
channels called
bronchiole.
 ii. Each bronchiole ends
with an alveolus.
 iii. Each alveolus has a
very thin wall which is
moist and contains a
network of blood
capillaries.

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Intercostals muscles …
 i. situated between the ribs.
 ii. two types
 A. internal intercostals muscles
 B. external intercostals
muscles
 ii. contract and relax to help
the breathing process.

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The ribs …
 protect the
lungs and
internal
organs.

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The diaphragm …
 piece of
muscles
situated at
the
bottom of
the lungs.

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Air is inhaled through …
 the nose inhales air and taken through
the trachea, bronchus, bronchiole and
finally to the alveolus.
Nose Trachea
Bronchus
Bronchiole
Alveolus

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Structure of Human
Respiratory System
Nasal Cavity Bronchiole
Pharynx
Epiglottis
Larynx
Lungs
Alveoli
Trachea
Bronchi

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Air passing over the mucous membrane
of the nasal cavity is moistened,
warmed and filtered
Or throat is located where
passage from the nose and
mouth come together
Is a flap of elastic tissue
that forms a lid over the
opening to trachea
1
2
3

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Or voice box is located between
The pharynx and the trachea.
Its contains two ligaments –
the vocal cords – that produce
sound when air moves
through them
If one of lobe is injured or
disease, the order lobes may
be able to function normally
4
5

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Inside the lungs, the
bronchi branch into
smaller tubes called
the bronchioles
6

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At the ends of the bronchiole are
bunches of alveoli, air sacs,
arranged like grapes on a stem
From the larynx, air enters the
Trachea or windpipe, which
Leads toward the lung
The trachea divides into two
Tubes called bronchi
7
8
9

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4. Next Page 1.1b: Breathing Mechanism
Review 1.1
3. Structure of the Human Respiratory System
1. Learning Outcomes
2. Human Respiratory System
 HUMAN BREATHING MECHANISM
EXIT
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