Download Lesson 10a: Respiratory System

SNC2P: Biology
NAME:
MS. WONG (ANSWER KEY)
Date: _______________
 The task of respiratory system is to exchange oxygen and
carbon dioxide between the body and its surroundings.
 The main parts of the respiratory system are nose, mouth,
trachea, bronchi, bronchioles, lungs, rib cage +
muscle, and diaphragm.
 Gas exchange takes place in the air sacs (alveoli) in the lungs.
These sacs are surrounded by capillaries.
Respiration 3D Medical Animation
http://www.youtube.com/watch?v=HiT621PrrO0
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 Branching out → to increase surface area (such as tree roots) where
oxygen can be absorbed; much more than if the lungs were one
hollow chamber.
 Tiny thin-walled blood vessels called capillaries surround each
alveolus.
 Oxygen passes through the walls of the alveoli and into the
capillaries and is carried throughout the body.
 Oxygen is used to burn food in the form of simple sugars, to release
energy. This is called cellular respiration.
 The waste products of this process are carbon dioxide and water,
which diffuse from the cells through the capillary walls and into the
blood. They are carried back to the alveoli and exhaled from the
lungs.
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Gas Exchange
Oxygen Transport
 The air we breathe into our lungs has a higher concentration of oxygen
than the blood in the capillaries around the air sacs (alveoli).
 The oxygen diffuses through the air sacs (alveoli) and the
capillaries into the blood.
 Oxygen moves from the lungs into the blood, and the blood transport the
oxygen to other parts of the body.
Removing Carbon Dioxide
 Carbon dioxide is a waste gas produced by the body as the body uses
energy to move, grow and repair itself.
 The blood carries carbon dioxide to the lungs.
 Carbon dioxide diffuses from the blood into the air sacs (alveoli).
 Carbon dioxide is then released through the mouth or nose when we
breathe out.
Respiration
http://www.youtube.com/watch?v=bwXvqSqAgKc
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Breathing
Breathing air in and out is simply a mechanical process related to
pressure changes caused by the increase and decrease of the chest
cavity size.
Breathing
http://www.youtube.com/watch?v=gYSIWceGMxY&NR=1
http://www.youtube.com/watch?v=Mf8xTqfspp4&feature=related
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When inhaling,
 diaphragm contracts and drops down.
 ribs expand outward, making the chest cavity larger.
 This causes the pressure in the cavity to decrease, resulting
in air being drawn into the lungs which causes them to
expand.
When exhaling,
 the diaphragm relaxes and moves up, and
 the ribs settle down.
 The cavity is made smaller, causing the pressure to
increase and results in the lungs contracting and forcing
carbon dioxide-laden air out of the lungs.
MUCUS & CILIA
The nose and air passages produce a slippery liquid called
mucus, which helps to warm and moisten the air and allows it to
travel the airways more easily.
Mucus also helps to trap dirt and dust particles and some
bacteria.
Tiny hairs called cilia, located on the inner walls of the air
passages, slowly move the mucus up toward the throat and
nose, carrying with it any foreign particles. If particles irritate the
nose, a sneeze may occur.
If the particles are located deeper in the air passages a hearty
cough will move them out. Much more mucus is produced
when the body is fighting a cold.
There are special epithelial cells that line the larger bronchi.
Each cell has about 250 cilia growing from it.
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Goblet cells located between the epithelial cells produce
almost half a cup of mucus a day.
As the cilia beat (about 1,0001,500 times per minute), they
move the mucus containing trapped foreign matter about 1020 mm in a minute or about a mile in a week.
When the mucus gets into the upper airways, it can be
coughed out. A cough is triggered when mucus or foreign
matter irritates nerve endings in the larynx, trachea, or larger
bronchi.
When irritating particles stimulate the nerve endings at the back
of the nasal cavity, a sneeze results. The impulse to sneeze can
be turned off briefly by pressing hard with a finger under the
nose.
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Respiratory Diseases
Chronic obstructive pulmonary diseases (COPD):
 Diseases that reduce the flow of air into and out of
the lungs; make it difficult to breathe
 Three main types: asthma, emphysema and chronic
bronchitis affect the ability of the respiratory system
to exchange gases.
 Asthma: airway swelling and mucus production
 Emphysema: tiny air sacs in the lungs collapse
and the wall between them are destroyed; less
oxygen can be picked up by the blood.
 Chronic bronchitis: tissues lining the airway
become swollen. Passageway for air is narrowed,
causing coughing and breathlessness.
Causes of respiratory disease:
1. Smoking and exposure to second-hand smoke
2. Exposure to pollution
3. Exposed to chlorine in swimming pools
Asthma
http://www.youtube.com/watch?v=S04dci7NTPk&feature=related
COPD
http://www.youtube.com/watch?v=u775bGjJazM
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What is Asthma?


Asthma is a chronic (long-term) disease that makes it hard to breathe.
If you have asthma, your airways (breathing passages) are extra sensitive. When
you are around certain things, your extra-sensitive airways can:
o Become red and swollen - your airways get inflamed inside. They fill up
with mucus. The swelling and mucus make your airways narrower, so it's
harder for the air to pass through.
o Become "twitchy" and go into spasm - the muscles around your airways
squeeze together and tighten. This makes your airways narrower, leaving
less room for the air to pass through.
o The more red and swollen your airways are, the more twitchy they
become.
Normal airways
Airways of a person without
asthma
Airways of a person with
asthma - redness and
swelling (inflammation)
Airways of a person with
asthma - tightened muscles
(bronchospasm)
In people without asthma, the
muscles around the airways are
relaxed, allowing the airways to
stay open. There is no swelling
or mucus inside the airways.
In people with asthma, the
inside of the airways can get
red, swollen, and filled with
mucus.
In people with asthma, the
muscles around the airways can
spasm and squeeze tighter.
This leaves less room for air to
pass through
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Emphysema
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
The bronchi and bronchioles are inflamed and continually swollen and clogged. This
causes the alveoli to swell. These fragile air sacs burst and merge together. This damage to
the alveoli makes it more difficult for the transfer of oxygen and carbon dioxide to take
place.

People with emphysema have difficulty breathing. It is usually caused by cigarette
smoking, or a severe form of bronchitis called chronic obstructive bronchitis. Very often, a
combination of these factors produces emphysema.
Who Gets Emphysema?

Both emphysema and COPD are very rare in young people, but the incidence * steadily
increases as people grow older, particularly during or after middle age. This is believed to
be due in large part to the cumulative effect of smoking on the lungs.

One person cannot catch it from another.

Emphysema is more common in men than it is in women, probably because more men
smoke cigarettes than women. However, it is believed that this difference will become
smaller because more teenage girls and young women are smoking cigarettes today than
years ago.

In the United States, more than 2 million people have emphysema, making it a common
disorder. More than 6 million people suffer from COPD. About 6 or 7 people per 100,000
die from emphysema each year, and COPD is the fourth most common cause of death in
the United States. The incidence of emphysema is even higher in European countries.
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Effects of Smoking and Other Causes

The great majority of emphysema cases are associated with cigarette smoking. It has been
found that people who are heavy smokers of cigarettes are 10 to 15 times more likely to
develop emphysema than are nonsmokers.

Environmental air pollution also may make a person more likely to develop chronic
bronchitis and emphysema.
What Are the Symptoms of Emphysema?

The main symptom of emphysema is shortness of breath. The person must breathe harder
to force carbon dioxide out of the lungs and draw in oxygen. A common outward sign of
emphysema is a barrel-shaped chest caused by overinflation of the lungs.
A slice of human lung tissue with pulmonary emphysema. The
affected lung area is the top portion, with severe lung damage in
the blackened area. Normal lung tissue is shown on the bottom
for comparison.
Dr. E Walker/Science Photo Library, Photo Researchers, Inc.
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Chronic Bronchitis
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If you have chronic bronchitis:
 the cells lining the inside of the bronchi are continuously red and swollen
 the airways in your lungs have become narrow and partly clogged with mucus
With chronic bronchitis, the mucus cannot be cleared. Instead of helping to clean the
lungs, the mucus blocks your airways. The mucus is thicker and more difficult to cough
up. This means it's easier for bacteria to settle in your lower airways and become
infected.
Chronic bronchitis is usually caused by cigarette smoke. It can also be caused by other
things. The main symptoms of chronic bronchitis are:

a persistent cough (cough that won't go away)

extra mucus (phlegm) in the lungs
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Number
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Functions
nasal cavity
mouth
epiglottis
trachea
bronchi
ribs
muscles
lungs
diaphragm
esophagus
bronchioles
capillaries
alveoli
warm, moisten and filter air
warm, moisten and filter air
ANSWERS
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
Functions
nasal cavity
mouth
epiglottis
trachea
bronchi
ribs
muscles
lungs
diaphragm
esophagus
bronchioles
capillaries
alveoli
warm, moisten and filter air
warm, moisten and filter air
prevent food from entering trachea
carries air to the bronchi
carry air to the lungs
helping with the process of breathing
helping with the process of breathing
gas exchange happens here
helping with the process of breathing
carries air to the alveoli
gas exchange (part of circulatory system)
gas exchange
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A flow chart showing the path oxygen takes when it
enters respiratory system
mouth or nose
trachea
bronchi
bronchioles
alveoli
capillaries
A flow chart showing the path carbon dioxide takes when
it leaves the circulatory system into the respiratory
system
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The Respiratory System
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The Respiratory System
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