The Respiratory Systemh

UEQ: How do we exchange oxygen to
and carbon dioxide from the human
The system that
brings oxygen into the body
and expels carbon dioxide out
of the body.
ensures that during inspiration,
or inhalation, air is brought
from the atmosphere to the
lungs by a series of cavities,
tubes and openings.
ensures that during expiration,
or exhalation, air is pushed out
of the lungs into the
atmosphere using the same
Major Organs
Nasal cavities
Paranasal sinuses
Pharynx, or throat
cavity , or mouth
Bone and cartilage support the nose internally
Two nostrils or nares
Air enters and leaves through here
Internal hairs guard nostrils
Prevents larger particles carried in air
Hollow space behind the nose
Divided into narrow canals separated from each other by cartilage
and bone – nasal septum.
Nasal conchae
 bones and bony processes that divide the cavity into
 Support the mucous membrane
 Increases surface area
 Pseudostratified ciliated columnar epithelium
 Secretes mucous from goblet cells
 Water evaporates from this lining moistening the air
 Mucus traps debris coming in with the air
 Lined with blood vessels
 As air enters, heat from blood transfers to air and warms it
 Adjusts air temp to body temp
Air filled spaces within the frontal, ethmoid,
sphenoid and maxillary bones of the skull and
opening into the nasal cavity.
Lined with mucous membranes – continuous
with the lining of the nasal cavity
Reduce the weight of the skull
Resonance chambers that affect quality of voice
Funnel shaped passage way
that connects the nasal and
oral cavities to the larynx
 Passage way for food moving
to esophagus, and air moving
to the larynx
 Helps to produce sound of
 Has three parts:
1. Nasopharynx: where the
nasal cavities open above
the soft palate
2. Oropharynx: where the oral
cavity opens
3. Laryngopharynx: area that
opens up into the larynx
REMEMBER!!!! Each time that you take a breath,
there are three very important things that happen.
1. The air that you breathe in is cleaned by tiny
hairs in your nose, trapping little bits of dirt and dust
and germs that come in through your nose.
2. As you breathe, the air is made slightly wet.
Your nose having damp passages does this.
3. The next thing that takes place when air enters
your nose is that the air is warmed. This happens
because the blood flows through the lining of the
nose and gives off heat.
"Snot", is just another word for mucus. When bits of
stuff get stuck in your nose hairs, it’s the mucus or
snot that surrounds the stuff and traps it.
Boogers are dried-up snot and dirty nose debris.
Encrusted mucus is filled with the junk that’s in the
air you breathe - dust, pollen, germs, sand, fungi,
smoke, small particles from outer space.
Model made up of gelatin (protein) and corn
syrup (sugar)
Mucus is made mostly of sugars and protein.
The long, fine strings you could see inside your
fake snot when you moved it around are
protein strands.
These protein strands make snot sticky and
capable of stretching
Complete the questions for a stamp.. 
Major Organs
Larynx, or voicebox
Trachea, or
The bronchial tree
The lungs
Cartilaginous structure that serves as a
passageway for air between the pharynx and
A triangular box
top of the triangle is located to the front of the
neck (Adam’s apple)
Framework of muscles and cartilage
 Thyroid cartilage
 Cricoid cartilage
 Epiglottic cartilage
Houses the vocal cords
Allows for air in and out of the trachea
Prevents foreign objects entering into trachea
Vocal folds
Composed of muscle tissue and connective tissue
Covered with mucous membrane
False vocal cords
Upper folds
 Do not produce sound
 Muscle fibers help close airway when swallowing
True vocal cords
Muscle tissue and elastic fibers
Forced air between TVC causes them to vibrate and
produce sound
Words = changing shapes of pharynx, oral cavity; and
use of the tongue
Pitch= contracting or relaxing muscles that alter tension
Opening between vocal cords
Durning normal breathing, relaxed vocal cords,
the glottis opens
During swallowing/ eating, muscles around
the false vocal cords contract, the glottis closes.
A flap of soft tissue above the vocal cords
The larnyx will move upward against the
epiglottis when swallowing to prevent food,
water and saliva from entering the lungs.
A tube that connects the larynx to the
primary bronchi
Walls consist of connective tissue and
smooth muscle
Reinforced by c-shaped cartilaginous rings
Lies anterior to the esophagus
Prevents the trachea from collapsing
Soft tissue that completes the c-rings, allow for
esophagus to expand as food moves through
The outermost layer of the mucous
membrane that lines the trachea is
pseudostratified columnar epithelium with
goblet cells.
Traps particles and moves it upwards to
pharynx to be swallowed
Tubes that allow air to pass through, and are reinforced
with cartilaginous rings, like the trachea.
Divided into the left and right primary bronchi, which
lead into the lungs
Divison is located in the mediastinum, approximately at the level
of the 5th thoracic vertebrae
 Branch into the secondary bronchi
 tertiary bronchi
 keep dividing until they are about 1 mm in diameter
Bronchi that are 1 mm in diameter are called bronchioles
Terminal bronchioles
 Respiratory bronchioles
 Alveolar ducts
 Alveolar sacs
 Alveoli
Paired, cone-shaped organs
Separated by the mediastinum
 Diaphragm and rib cage enclose them
Suspended by the bronchus and major blood vessels
Visceral pleura surrounds each lung
 Continues to the parietal pleura which attaches and surounds
the throacic cavity
 Potential space between the pleura = pleural cavity
 Filled with serous fluid
 Reduces friciton of lungs moving against the thoracic cavity
during breathing
Right lung has three lobes, the left lung only two –
due to the heart pointing towards the left
Broken even further into lobules, which house
bronchioles serving the alveoli
Lungs have about 300 million alveoli
Each alveoli sac is surrounded by blood
Made up of simple squamous epithelium
This is the site where gas exchange happens
Your check it questions
The diagram at the back of the packet
Why is it important for the capillaries
from the cardiovascular system to be
numerous and surround the alveoli?
When finished
with the
question, take a
moment and
breathe – notice
what happens.
Write it down.
Oxygen diffuses from alveolar walls and
enters the blood.(where it can now go to other
cells in the body)
Carbon Dioxide diffuses from the blood
through the walls and enters the alveoli.
(where it can be exhaled and released)
Using the picture below EXPLAIN the gas
exchange process:
Why do the blood cells start blue and
then turn red?
Has two phases
 Inspiration – moving air into the
 Expiration –moving air out of the
Active phase of ventilation
In this phase the diaphragm and muscles of the
ribcage contract – diaphragm moves downward and
looks flattened
The volume of the thoracic cavity will increase, so
does the lung volume
The pressure within the alveoli is
less than the pressure outside in the
atmosphere. There is a difference in
pressure (or pressure gradient) and
air will move into the body
Pressure inside the lungs and alveoli
decrease, atmospheric pressure will push
outside air into airways
During this time the pressure in the alveoli
drops 2mmHg below atmospheric pressure
In response, atmospheric pressure forces air
into the airways
The external intercostal muscles between
ribs are stimulated and move the ribs and
sternum upwards
Enlarges thoracic cavity even further
Internal pressure is further reduced;
increases amount of air into the lungs
Water within the serous fluid found in
between the visceral and parietal pleura
creates an attraction between the pleura,
and the membranes move upward
during inspiration
This expands the lung in all directions.
Too much water in the alveolar sacs
creates a surface tension that may
collapse the alveoli.
Certain cells within the alveoli secrete a
surfactant – lipids and proteins
Fills the alveolar air spaces – reducing
the tendency to collaspe, especially
when lung volumes are low
Makes it easier to inflate alveoli
Passive phase of ventilation
Come from elastic recoil and surface
No effort is required for air to leave the
Diaphragm and muscles of the ribcage
relax – diaphragm looks cone shaped
Pressure within the alveoli increases to
about 1mmHg above atmospheric
Forces the air out of the lungs
The volume of the thoracic cavity will
decrease, so does the lung volume
Involves muscles of the
back, chest, and neck
Thoracic cavity
increases more than
normal, for maximum
lung capacity
Usually during exercise
Contraction of the ribcage
muscles forces the ribcage to
move downward and inward
Involves the abdominal
muscles pushing against the
abdominal organs which
pushes against the
diaphragm, pushing more out
of the lungs
Usually during exercise,
singing, playing an
instrument, or blowing out a
And then the activity.
Warm UP: Are our lungs ever void
of air? Why or why not?
Why do we need to know this?
Knowing the amounts of air in the lungs and
how it flows through the respiratory system
helps to diagnose respiratory issues
Spirometry is the test that measures air volumes
in or out of the lungs.
Three distinct repiratory volumes can be measured:
 Resting Tidal volume
 Inspiratory reserve volume
 Expiratory reserve volume
One inspiration + one expiration = respiratory
Air that enters of leaves during a respiratory cycle is
the tidal volume
Respiratory cycle: One inspiration plus one
expiriation. (Breathe in- breathe out)
Resting Tidal volume- the normal amount
of air that enters the lungs and leaves the
lungs during a respiratory cycle.
 The average is about 500 milliliters of air per
breath in and the same amount out.
volume you
do not use
the total
amount of
space in
your lungs!
They only
use about
Inspiratory Reserve Volume: When you
take a deep breath in to hold more air than
a usual breath. “Forced inhalation”.
Expiratory Reserve Volume: Forced
expiration. Expelling air beyond the tidal
volume. Even after the most forceful
exhale however you still have air left in
your lungs.
 This
left over air is called the Residual Volume.
Vital Capacity: Combining the tidal volume
with both the inspiratory reserve volume and
the expiratory reserve volume.
Total Lung Capacity: The vital capacity plus
the residual volume. All the possible air that
can come into or out of the lungs, including
the air that never leaves the lungs.
Respiratory centers and control of breathing…
 Medullary respiratory center-
controls both inspiration and
Found within the pons and
medulla oblongata
Medulla oblongata has two
Ventral respiratory group –
controls basic rhythm
 Dorsal respiratory group- controls
the diaphragm
Factors that Affect breathing
flow charts.. CHECK IT!
 PP. 456- 458
 Create flow charts for the following factors that affect
CO2 levels
O2 levels
Depth of breathing
Emotional upset
Holding your breath
Location: The alveoli
Method: Diffusion
 Partial pressure: In a mixture of
gases such as air or blood, each gas
accounts for a portion of the total
pressure the mixture produces. The
amount of pressure each gas
contributes is the partial pressure.
Diffusion of Gases:
When blood reaches the alveolus / lungs the blood
is oxygen poor- it has depleted its oxygen source
to the rest of the body and needs to “pick up
Diffusion of Gases:
 Due to the pressure gradient, oxygen
will move from the alveoli to the blood
 In other words, there is more oxygen in
the alveoli than the bloodstream, so
oxygen will naturally move into the
So what about
Carbon Dioxide?
 Carbon dioxide will be
higher or lower
in the bloodstream.
 Carbon dioxide will
move into or out of
the bloodstream into the
alveoli where it will be
expelled out of the body.
Color and label the diagram