Download Respiratory System - Sr Biology: 7(AE)

Respiratory System
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Respiratory System
What are the major organs and
functions of the respiratory system?
Organs: Air
passages, lungs
Function: Carries air
into and out of lungs,
where gases (oxygen
and carbon dioxide
are exchanged)
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Introduction to Respiratory System
- Respiratory system consists
of tubes that filter incoming
air and transport it to
microscopic alveoli where
gases are exchanged.
- Process of exchanging gases
between atmosphere and
body cells is called
respiration and consists of:
- 1. Ventilation - gas
exchange between blood and
lungs
- 2. Gas transport in
bloodstream
- 3. Gas exchange between
blood and body cells
- 4. Cellular respiration
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Were you listening?
Respiration consists of four parts.
What are they?
1. Ventilation - gas
exchange between
blood and lungs
2. Gas transport in
bloodstream
3. Gas exchange between
blood and body cells
4. Cellular respiration
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Organs of the Respiratory System
Two groups:
Upper respiratory
tract (nose,
nasal cavity,
sinuses, and
pharynx)
Lower respiratory
tract (larynx,
trachea,
bronchial tree,
and lungs)
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Nose
- Bones and
cartilage support
nose
- Two openings
(nostrils)
- Hair filters large
particles
- Mucous traps
smaller particles
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Nasal Cavity
- Hollow space
behind the nose
- Nasal septum –
divides the nose
(bone)
- Deviated Septum
– when the
septum bends to
one side
Air is warmed as it enters the nasal
cavity, sticky mucus traps particles which
are pushed toward the pharynx and
swallowed.
Paranasal Sinuses
- Pairs of air filled
sacs surrounding
the nasal cavity,
above and
between the
eyes, and behind
the cheeks
- Reduce the
weight of the
skull
- Resonant
chambers for
voice
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Pharynx
- Behind oral
cavity
- Between nasal
cavity and
larynx
- Common
passageway for
air and food.
- Aids in producing
sounds for
speech.
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Larynx
- Enlargement at top of
trachea and below
pharynx
- Conducts air in and out
of trachea
- Houses vocal cords
- Composed of framework
of muscles and cartilage
- Thyroid cartilage “Adam’s
Apple”
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Larynx
- False vocal folds
(do not produce
sound) – help close
airway during
swallowing
- True vocal folds
(produce sound) –
changing shape of
pharynx and oral
cavity changes
sounds into words
Contracting and relaxing muscles
changes pitch (increased tension =
higher pitch)
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Trachea
- Epiglottis – flaplike
structure above trachea,
allows air to enter larynx,
during swallowing it
presses downward and
prevents food from
entering air passages
- Trachea (windpipe) –
flexible cylinder, extends
downward in front of
esophagus (tube from
mouth to stomach)
- Contains 20 C-shaped
pieces of hyaline cartilage
that prevent trachea from
collapsing
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Bronchial Tree
- Bronchial tree
consists of
branched tubes
leading from
trachea to
alveoli.
- Bronchial tree
begins with the
two primary
bronchi, each
leading to a lung.
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Alveoli
- Gas exchange
between blood
and air occurs
in the alveoli.
Primary bronchii – left and right  bronchioles 
alveolar ducts  alveolar sacs  alveoli (gases are
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exchanged between alveoli and blood stream)
Diffusion
- Gases diffuse from
areas of higher pressure
to areas of lower
pressure.
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Alveolar Gas Exchanges
- Alveoli are the
only sites of gas
exchange between
atmosphere and
blood.
- Alveoli are tiny
air sacs clustered
at the end of the
bronchioles.
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Lungs
- Soft
spongy,
cone-shaped
organs in
chest cavity
- Alveoli look
like a
cluster of
grapes
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Lungs
- Left Lung –
smaller, 2
lobes
- Right Lung –
larger than
left, 3 lobes
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Review
Complete the chart below by describing the
functions of the major respiratory organs.
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Gas Transport
- Over 98% of oxygen is
carried in blood bound to
hemoglobin of red blood
cells, producing
oxyhemoglobin.
- Oxyhemoglobin is
unstable in areas where
concentration of oxygen is
low, and gives up its
oxygen molecules in those
areas.
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Breathing Mechanism
- Ventilation
(breathing) movement of
air in and out
of lungs
- Inspiration –
inhalation
- Expiration exhalation
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Inspiration (Inhalation)
-
-
-
Diaphragm moves
downward and
atmospheric pressure in
lungs falls, forcing air
into airways
Muscles around ribs
contract, raising ribs and
sternum and enlarging
chest cavity.
Lungs expand with air
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Expiration (Exhalation)
-
-
Diaphragm and other
muscles relax and
move upward.
Pressure forces air
out.
Contractions increase
air pressure within
chest cavity, forcing
air out.
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Respiratory Air Volumes and
Capacities
-
-
-
Spirometry:
Measurement of
different air volumes.
It describes four
distinct respiratory
volumes.
Respiratory cycle: One
inspiration followed by
one expiration.
Tidal volume: Amount
of air that enters or
leaves lungs during one
respiratory cycle.
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Respiratory Air Volumes and
Capacities
-
-
-
Inspiratory reserve
volume:During
forced inspiration,
an additional volume
that can be inhaled
into the lungs.
Expiratory reserve
volume During a
maximal forced
expiration, the
amount of air that
can be exhaled
Residual volume: air
that remains in
lungs after
maximum
expiration.
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Respiratory Air Volumes and
Capacities
-
-
Vital capacity:
the maximum
volume of air
that can be
exhaled after
taking deepest
breath possible
Dead space:
the air
remaining in
bronchial tree
that does not
contribute to
gas exchange.
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Term Review!
Give the definitions for each of the
air volumes and capacities.
Tidal Volume
Amount of air that enters or leaves lungs during one respiratory cycle
Inspiratory Reserve Volume
During forced inspiration, an additional volume that can be inhaled into lungs.
Expiratory Reserve Volume
During a maximal forced expiration the additional volume that can be exhaled.
Vital Capacity
maximum volume of air that can be exhaled after taking deepest breath possible
Dead Space
air remaining in bronchial tree that does not contribute to gas exchange
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Control of Breathing
- Breathing is
involuntary act
- Muscles under some
voluntary control (we
can choose to hold
our breath)
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Respiratory Center
- Respiratory
Center: groups
of neurons in
brain that
control
inspiration and
expiration
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Factors Affecting Breathing
-
Chemosensitive Areas –
detect concentrations of
chemicals like carbon
dioxide and hydrogen
- 1. Rise in CO2
- 2. Low blood oxygen
- 3. Inflation Reflex –
regulates depth of
breathing, prevents
overinflation of lungs
- 4. Emotional Upset,
fear and pain
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Factors Affecting Breathing
- Hyperventilation – increase
breathing for a short time
lowers the blood CO2
concentration. Following
hyperventilation you can hold
your breath for a longer
period because it takes
longer to increase the blood
CO2 levels. People breathe
into a paper bag to increase
CO2 levels so that they will
maintain the proper balance.
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Review Question
What is the respiratory center and
in what area(s) of the brain is it
based?
The respiratory center is
groups of neurons in brain
that control inspiration
and expiration
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Hypoxia
Oxygen
deficiency
Can be caused
by inadequate
blood flow or
poisons
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Asphyxia
Excess C02 in the blood, lack of oxygen
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Illnesses Related to the
Respiratory System
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Cystic Fibrosis
Asthma
Bronchitis
Apnea
Emphysema
Lung Cancer
Altitude Sickness
Chronic Obstructive Pulmonary Disease (COPD)
Sinusitis
Bacterial or Viral Infections (cold, flu, pneumonia)
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