Transcript The Respiratory System

UEQ: How do we exchange oxygen to
and carbon dioxide from the human
body?
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The system that
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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
structures.
 WHAT
ORGANS ARE APART OF
THE UPPER RESPIRATORY
TRACT?
Major Organs
Nose
Nasal cavities
Paranasal sinuses
Pharynx, or throat
Accessory
Oral
cavity , or mouth
Organs
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Bone and cartilage support the nose internally
Two nostrils or nares
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Air enters and leaves through here
Internal hairs guard nostrils
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Prevents larger particles carried in air
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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
passageways
 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
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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
speech
 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
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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.
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Snot:
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"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:
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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.
Achoo…
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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.. 
 WHAT
ORGANS ARE APART OF
THE LOWER RESPIRATORY
TRACT?
Major Organs
Larynx, or voicebox
Trachea, or
windpipe
The bronchial tree
The lungs
Accessory
Organs
Glottis
epiglottis
Diaphragm
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Cartilaginous structure that serves as a
passageway for air between the pharynx and
trachea.
A triangular box
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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
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Houses the vocal cords
Allows for air in and out of the trachea
Prevents foreign objects entering into trachea
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Vocal folds
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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
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True vocal cords
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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
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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.
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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.
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A tube that connects the larynx to the
primary bronchi
Walls consist of connective tissue and
smooth muscle
Reinforced by c-shaped cartilaginous rings
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Lies anterior to the esophagus
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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
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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
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Bronchi that are 1 mm in diameter are called bronchioles
Terminal bronchioles
 Respiratory bronchioles
 Alveolar ducts
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 Alveolar sacs
 Alveoli
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Paired, cone-shaped organs
Separated by the mediastinum
 Diaphragm and rib cage enclose them
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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
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 Filled with serous fluid
 Reduces friciton of lungs moving against the thoracic cavity
during breathing
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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
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Lungs have about 300 million alveoli
Each alveoli sac is surrounded by blood
capillaries
Made up of simple squamous epithelium
This is the site where gas exchange happens
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Your check it questions
The diagram at the back of the packet
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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.
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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?
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Has two phases
 Inspiration – moving air into the
lungs
 Expiration –moving air out of the
lungs
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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
naturally.
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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
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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
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Passive phase of ventilation
Come from elastic recoil and surface
tension
No effort is required for air to leave the
body
Diaphragm and muscles of the ribcage
relax – diaphragm looks cone shaped
Pressure within the alveoli increases to
about 1mmHg above atmospheric
pressure
Forces the air out of the lungs
The volume of the thoracic cavity will
decrease, so does the lung volume
MAXIMUM INSPIRATION
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Involves muscles of the
back, chest, and neck
Thoracic cavity
increases more than
normal, for maximum
lung capacity
Usually during exercise
FORCED EXPIRATION
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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
candle
And then the activity.
Warm UP: Are our lungs ever void
of air? Why or why not?
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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
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Spirometry is the test that measures air volumes
in or out of the lungs.
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Three distinct repiratory volumes can be measured:
 Resting Tidal volume
 Inspiratory reserve volume
 Expiratory reserve volume

One inspiration + one expiration = respiratory
cycle.

Air that enters of leaves during a respiratory cycle is
the tidal volume
Respiratory cycle: One inspiration plus one
expiriation. (Breathe in- breathe out)
1.
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.

During
Tidal
volume you
do not use
the total
amount of
space in
your lungs!
They only
use about
75-80%
2.
Inspiratory Reserve Volume: When you
take a deep breath in to hold more air than
a usual breath. “Forced inhalation”.
3.
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.
4.
2.
1.
5.
3.
6.
4.
5.
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
expiration
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Found within the pons and
medulla oblongata
Medulla oblongata has two
groups
Ventral respiratory group –
controls basic rhythm
 Dorsal respiratory group- controls
the diaphragm
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Factors that Affect breathing
flow charts.. CHECK IT!
 PP. 456- 458
 Create flow charts for the following factors that affect
breathing
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CO2 levels
O2 levels
Depth of breathing
Emotional upset
Holding your breath
Hyperventilation
HOW AND WHY GAS
EXCHANGE HAPPENS:
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
more”.
Diffusion of Gases:
 Due to the pressure gradient, oxygen
will move from the alveoli to the blood
stream.
 In other words, there is more oxygen in
the alveoli than the bloodstream, so
oxygen will naturally move into the
bloodstream.
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
GAS TRANSPORT
Factors affecting release of O2
 Increase in CO2
concentration= increase
in O2 release
 If blood
 Becomes acidic
 Temperate increases
 More O2 is released to
skeletal muscle during
physical activity; less O2
released to non active
cells
 HYPOXIA – deficiency of
O2 reaching tissues
GAS TRANSPORT - OXYGEN
HEMOGLOBIN
 98% of oxygen in blood
binds to hemoglobin
 a protein in red blood
cells that carries oxygen
OXYHEMOGLOBIN
 PO2is high – oxygen
dissolves in blood and
combines with
hemoglobin to form
oxyhemoglobin
 Unstable bonding
 As PO2 decreases in the
body, O2 is released from
oxyhemoglobin
 O2 diffues across the
membrane of cells to be
used in cellular respiration
CO2 Transport
 Capillary blood gains CO2, as tissues have increased
levels of PCO2
 Transported in three ways to the lungs:
 Dissolved in plasma
 Bound to hemoglobin
 Bicarbonate ions
 Amount of CO2 dissolved in plasma dependent on its
partial pressure
 Increased PCO2 = more CO2 in solution
 Only 7% of CO2 transports in this form
GAS TRANSPORT
Carbaminohemoglobin
 CO2 loosely bonds with
hemoglobin =
carbaminohemoglobin
 Decomposes readily in
regions of low PCO2 –
releasing CO2
Bicarbonate Ions
 Most important CO2
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 Only about 23% of the
CO2 carried in the blood
is formed in molecule, as
this reaction happens
slowly
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transport mechanism
CO2+ H2O => H2CO3
(carbonic acid)
Occurs slowly in plasma
Carbonic anhydrase speeds
up reaction, releasing H+
and HCO3- (bicarbonate
ions)
Bicarbonate ions diffuse into
the plasma – 70% of all CO2
in blood is transported this
way
CO2 Transport Continued
 Plasma release CO2
 Dissolved CO2 diffuses into the alveoli (alveoli PCO2
is low
 Bicarbonate Ions Release CO2
 As blood passes through the capillaries of the lungs
 At same time H+ and HCO3- combine to make H2CO3
under influence of carbonic anhydrase
 H2CO3 breaks down quickly to form CO2 and H2O
 CO2 then diffuses into the alveolus
CO2 Transport Continued
 Carbaminohemoglobin release of CO2
 As blood passes through the capillaries of the
lungs
 Release of CO2 happens
 Will continue until PCO2 of blood and alveolar
air are at equilibrium