Transcript 17.3
The Respiratory System
Chapter 17 Lesson 3
Function of the Respiratory System
Respiration (the exchange of gases between your body and your
environment).
2 parts:
External respiration: exchange of oxygen and carbon dioxide between the blood and
air in the lungs.
Internal respiration: exchange of gases between the blood and cells of the body.
Structure of the Respiratory System
Lungs
Nose
Mouth
These are supported by the diaphragm (a muscle that separates the chest
and abdominal cavities).
Without the diaphragm, respiration would be impossible.
Lungs
Principal organ of your respiratory system.
Take in oxygen from the air you inhale and return carbon dioxide (c02) to
the air when you exhale.
Lungs get their power from the diaphragm.
The Breathing Process
When you inhale, the rib muscles and diaphragm contract.
Diaphragm moves downward and ribs pulled up and out.
This movement enlarges the chest cavity, creating lower pressure in the lungs.
Air rushes into the lungs to equalize the pressure between the lungs and
outside environment.
The reverse happens when you exhale (diaphragm relaxes, moving upward, and
the ribs move inward, increasing pressure within the lungs.
Video
Structure of the
Lungs
Each lung is divided into sections
called lobes.
3 lobes in the right lung & 2 in the left.
The airways that lead into the lungs
divide to form a network called
bronchioles.
At the end of each bronchiole is a
cluster of thin-walled air sacs called
alveoli.
These alveoli are covered with a lots of
capillaries.
It is these alveoli where the exchange
of air and carbon dioxide take place.
Other Respiratory Structures
There are two points of entry for air to get to your lungs:
Nose & Mouth
Breathing through the nose has an advantage in that it is filtered and
cleaned by mucous membranes and tiny hairs called cilia.
From your nose, air moves through the pharynx (throat) and into the
trachea (windpipe).
The trachea is also lined with mucous membranes and cilia.
These are the 2nd line of defense to trap foreign particles and keep them from entering
your lungs.
Air completes its journey to the lungs through the bronchi (the airways that
connect the trachea to the lungs).
Larynx & Epiglottis
On its journey to the lungs, air passes over two
structures that are not directly related to
inspiration (when oxygen is taken in) – but are
very important.
Larynx (voice box)
Contains vocal cords. As air passes over
these cords, the cords vibrate and
produce sound. Without them, speech is
not possible.
Epiglottis (flap of cartilage in front of the
entrance to the larynx).
At rest, the epiglottis is open to allow air to
pass into the lungs.
When you swallow, it closes to prevent
food and liquid from being inhaled.
“Went down the wrong pipe”
Epiglottis failed to close properly,
allowing food or drink to enter your
trachea.
Care of the Respiratory System
Respiratory System (RS) is highly susceptible to infection from both bacteria
and viruses.
Avoid putting your hands up to your nose or mouth – as your hands are a
carrier of disease organisms. It is vital to develop an awareness of this habit
and do it less. Wash your hands!
Avoid pollutants such as tobacco smoke.
Exercise regularly! This helps to keep your lungs working efficiently.
Respiratory System Problems
Bronchitis
Asthma
Pneumonia
Tuberculosis
Emphysema
Sinusitis
Bronchitis
Inflammation of the bronchi.
Symptoms: wheezing, shortness of breath, and
coughing.
Can be acute or chronic. Both types are
common in smokers and areas of high pollution.
Acute bronchitis comes on suddenly and usually
clears up quickly. It is usually a complication of a
viral infection such as cold or flu.
Chronic bronchitis is longer-lasting, and recurring.
Most important in the treatment of chronic
bronchitis is avoiding respiratory irritants such
as cigarette smoke, dust, fumes, and other
air pollutants.
Asthma
Is an inflammatory condition in which the
small airways in the lungs called bronchioles
become narrowed, causing difficulty
breathing.
The mucous lining swells and secretions
build up, making breathing more difficult.
Can be triggered by exertion, emotion,
infection, allergies, weather.
1 in 20 people (1 in 10 children) are
asthmatic.
Treatment: bronchodilators – medicine that
relaxes and widens airways.
Most people administer the medication
themselves.
Pneumonia
Pneumonia is inflammation of the lungs.
Not a single disease but the name for several types of lung
inflammation caused by bacteria or viruses.
2 main types:
Lobar pneumonia
One lobe of the lung is affected at first.
Bronchial pneumonia
Inflammation starts in the bronchi and then spreads to
lungs
Symptoms: fever, chills, shortness of breath, sever cough.
Chest pain that is worse when breathing may occur because
of pleurisy (inflammation of the membrane lining of the lungs
and chest cavity).
Tuberculosis
Infectious bacterial disease of the lungs.
Symptoms: fever, sweating, weakness,
poor appetite, shortness of breath, sever
coughing.
Pretty care in developed countries (such
as U.S.) because on modern antibiotic
medicines/immunizations.
Emphysema
Disease in which the alveoli in the
lungs burst and blend to form
fewer, larger sacs with less
surface area. As a result, normal
exchange of carbon dioxide and
oxygen in alveoli is disrupted.
Symptoms: difficulty breathing,
chronic cough.
Cause: breathing in foreign
matter such as smoke, and other
air pollutant over a long period of
time. In almost all cases it is
caused by cigarette smoking.
The condition cannot be
reversed.
Sinusitis
Sinusitis is an inflammation of
the membrane lining the
facial sinuses, the air-filled
cavities in the bones that
surround the nose.
Cause: infection that spreads
to the sinuses from the nose.
Symptoms: fever, stuffy nose,
ache in affected area
Treatment: antibiotics,
decongestant drops/spray, or
steam inhalation