Download The Respiratory System

What is Breathing?
The mechanical
movement of air in
and out of your lungs
To
provide a constant supply of
oxygen to keep your body cells
functioning
To remove carbon dioxide from the
body cells
 The
Original Song
Organs of the Respiratory
System
 Brings
air into the body
 Nasal hairs in nostrils trap dust
 This is the first line of defense for the body
Warms
& moistens air
Glands
that produce sticky mucus
line the nasal cavity
Lined with Cilia


traps dust
sweep mucus and trapped material to the back
of the throat where it can be swallowed
 At
the lower end of the pharynx is a flap of
tissue called the epiglottis

covers the trachea during swallowing so that
food does not enter the lungs
Uvula
 “Voice
box”
 The airway where two folds of tissue,
called vocal cords, are attached
 Air-conducting
tube
 Connects the larynx to the bronchi
 Lined with mucous membranes and cilia
 Contains
Strong Cartilage Rings
to protect it from Collapse and Injury
 Smoking
paralyzes cilia for 20 min.
 Smoking increases production of mucous
 Two
short tubes that branch off the lower
end of the trachea
 Carries air into the lungs.
 Lined with some cartilage
 Tiny
branches of air tubes in the lungs
 Connect bronchi to alveoli
 No cartilage
 Tiny,
thin-walled, grapelike clusters at the
end of each bronchiole
 Lined
with thin moist membranes
 Surrounded
by capillaries (small blood
vessels)
Where
carbon dioxide and oxygen
exchange take place
 They
are the
 About
Respiratory Surface
30 million Alveoli in Lung
 Each
Alveolus has as many as 1,800
blood capillary contacts.
MAJOR SURFACE OF GAS EXCHANGE
 Blood
carried to the
lungs has a Low
Concentration of O2
and a High
Concentration of
CO2 compared to
the air in the alveoli
 CO2
diffuses out
through the alveoli
and O2 diffuses into
blood
CO2
O2
O2
CO2
O2
CO2
 Muscle
wall between the chest and the
abdomen that the body uses for
breathing
 Active
phase
 Diaphragm is pulled downward
 Lungs expand (oxygen fills up lungs)
 Ribs are pulled up and out
 Chest cavity is enlarged
 Pressure within the chest is reduced
 Passive
phase
 Diaphragm relaxes and pushes upward
 Lungs deflate (air in squeezed out)
 Size of chest cavity decreases
 Rib muscles relax – ribs drop
 Pressure in chest cavity increases
Fig. 42-25
Rib cage
expands as
rib muscles
contract
Air
inhaled
Rib cage gets
smaller as
rib muscles
relax
Air
exhaled
Lung
Diaphragm
INHALATION
Diaphragm contracts
(moves down)
EXHALATION
Diaphragm relaxes
(moves up)

Mainly an involuntary process
controlled by the medulla of the
brain
The
medulla monitors the amount of
CO2 in the blood
When
CO2 increases - nerve
impulses are sent to the diaphragm
and chest muscles to increase the
rate of breathing
 Sensors
in the aorta and carotid arteries
monitor CO2 concentrations in the blood
 These
sensors exert control over breathing
Fig. 42-27
Cerebrospinal
fluid
Pons
Breathing
control
centers
Medulla
oblongata
Carotid
arteries
Aorta
Diaphragm
Rib muscles
ASTHMA
A condition in which breathing is impaired
by constriction of bronchi and
bronchioles, cough, and thick mucus
secretions.
Causes:
- allergens ( pollen, pets, cockroach
proteins)
- pollutants
- Infection
- Emotional Stress.
Treatment:
Alleviate the symptoms immuno-suppressors and
bronchodilators
Bronchitis
Inflammation of the mucous membranes of
the bronchi.

Causes: Associated with smoking, pollution,
and bacterial or viral infections.
Pneumonia
Acute inflammation of the lungs.

Symptoms: high fever, chills, headache,
cough, and chest pain.


Causes: Bacterial, fungal, or viral infections.
Treatment: Antibiotics or other
antimicrobials.
Emphysema:
Permanent and irreversible destruction of
alveolar walls, resulting in ……….
Loss of lung elasticity and gas exchange
surface.
Emphysema:
 Symptoms:
shortness of breath, difficulty
breathing, cough, weakness, anxiety,
confusion, heart failure and respiratory
failure.
 Causes:
Smoking, pollution, old age, and
infections.
 Treatment:
No cure.
Oxygen to help breathing.
Tuberculosis
A
specific bacteria that infects the lungs.
The formation of a Tubercle and then
infection results in the loss of elasticity of
the capillaries around the alveoli causing
poor gas exchange.
Lung Cancer
Cancerous tumors grow and destroy the lung
tissue.

Symptoms: bloody sputum, persistent cough,
difficulty breathing, chest pain

Causes: Smoking (50% of all cases) and
pollution (radon, asbestos).

Treatment: Surgery is most effective, but only
50% of all lung cancers are operable by time
of detection. Other treatments include
radiation and chemotherapy.