The Respiratory System
 Respiration  taking in
O2 (oxygen) and releasing
CO2(carbon dioxide).
 Other functions include
inhaling and exhaling,
and conditioning the air
entering the body.
 Air is warmed by blood
vessels.
The Overall Respiratory System Labelled
Pleural
Membrane
Diaphragm
The Respiratory System – Flow of Air
 Air enters in through the nasal
passage. Dust is filtered out by hairs
(called cilia) and mucus. Air is also
warmed in this region
 Air also enters in through the mouth
 Air passes through the pharynx
(located at the back of the mouth) to
the trachea and into the lungs.
 The larynx is made of cartilage rings
and is lined with cilia
Cilia and Mucous
 Cilia are hair like
projections used to capture
bacteria and/or dust
particles
 Cilia can be found in the
linings of nasal
passageway, trachea,
bronchi, and bronchioles.
 Mucous is also located in
these regions
The Larynx
 The larynx is the enlarged
portion of the trachea; contains
muscular vocal cords. Vibrations
are mixed with air to produce
sound.
 The larynx, known as the voice box
 The vocal cords are made of folded
structures.
 While breathing, the vocal cords a
spread far apart
 When the vocal cords are brought
together they create vibrations as air
passes

Sound is made
Larynx – How Sound is Made (Video)
The Respiratory System – Flow of Air
 The epiglottis is located at the
top of the trachea. When you
swallow, it closes so that food
cannot enter your trachea.
 From the trachea, air enters the
bronchi and then into the small
extensions called the
bronchioles.
 The bronchioles are no longer
made up cartilage but rather they
consist of soft spongy tissue
What Happens When You Fluid goes
down the wrong pipe?
 When food or liquid is consumed
and it enters into the trachea
instead of the esophagus
 Known as pulmonary aspiration
 The cilia in the trachea will move
the food/liquid in the opposite
direction
 The diaphragm also helps to
reverse the process
Video: Epiglottis Preventing Choking
Larynx to Trachea
The Respiratory System – Alveoli
 Bronchioles branch into smaller alveoli. This is where gas exchange
with blood occurs. The blood receives O2 and releases CO2 through
the capillaries, in a process called diffusion.
Air Flow Chart
Pharynx
Trachea
Bronchus
Bronchiole
Alveoli
Breathing
What is air composed of?
Inhalation
 The process of taking air
into the lungs
 Occurs when air pressure
outside the body is greater
than inside

Diaphragm and intercostals
muscles contracts creating
more space in lungs  this
creates low pressure

Diaphragm moves down

Rib cage moves up and out
Exhalation
 The process of taking air
out of the lungs
 Occurs when air pressure
inside the body is greater
than outside

Diaphragm and intercostals
muscles relaxes creating less
space in lungs  this creates
high pressure

Rib cage moves down and in

Diaphragm moves up
Inhalation and Exhalation
The Respiratory System – Breathing
Constructing A Model Lung Using
Simple Materials - Demo
Exhalation vs. Inhalation Video
Clip
High Altitude Breathing
 At high altitudes, the air pressure is
lowered and thus thinner than at sea level
 Oxygen and other gases are present in the
air at equal amounts, however there is
less air in general.
 Breathing at these altitudes can be
difficult since a lack of oxygen is entering
the body
 The result is a condition known as hypoxia
(low oxygen)
High Altitude Breathing
 Altitude sickness often results from moving to high
altitudes and not adjusting to the air
 In response to low air, the body increases the
breathing rate which helps to bring in more oxygen
to the alveoli.
Adapting to Low Oxygen
 After approx. two weeks, individuals will adapt to
low oxygen levels by producing more red blood
cells.
 Individuals living at high altitudes have even evolved
to contain more alveoli and more lung capillaries.
Case Study: Athletes
 In the 1968 Olympics in Mexico
(~7000ft alt.), short explosive events
such as the 100-400m dash, produced
record-breaking levels whereas
endurance events were well below
expectations.
How can these results be
explained?
 At high altitudes, the air is less dense
thus allowing for less resistance.
 At high altitudes, there is less air
causing more rapid fatigue
5 minute
break
Respiratory Impairment
 Drowning:
 Laryngospasm: The larynx closes and death
occurs by asphyxiation (choking)
 Fresh water: Water wipes away lipoprotein
surrounding the alveoli  alveoli collapse  no gas
exchange
 Salt water: Water leaves blood and fills lungs 
oxygen cannot reach alveoli
 Carbon Monoxide (CO) Poisoning: CO binds
to the oxygen receptors in the red blood cells
more tightly than oxygen
 Prevents oxygen from entering blood
Respiratory Impairment
 Air Pollution:
 Includes airborne pollutants such as carbon monoxide,
nitrogen oxides, chlorine, methane, and dust particles
 Can lead to aggravated immune systems  asthma
Smoking
Statistics
 By 2030, if current trends continue, smoking will kill
one in six people.
 Every eight seconds, someone dies from tobacco use.
 About 15 billion cigarettes are sold daily - or 10 million
every minute.
 Among young teens (aged 13 to 15), about one in five
smokes worldwide.
 Between 80,000 and 100,000 children worldwide start
smoking every day - roughly half of whom live in Asia.
Activity: Smoking
 Use/share a smartphone and quickly research one
harmful chemical in cigarettes
Smoking
 Smoking primarily damages cilia
 Recall: Cilia helps filter out harmful
bacteria and dust particles
 Cigarette smoke has over 1000 times
the level of carbon monoxide that is
known to be harmful to human
health.
 Cigarette smoke contains 4000
chemicals
 40 of which increase the incidence of
cancer
List of Harmful Chemicals Discussion
Homework
Pg. 447 # 10-12