2. The breathing or respiratory system is located in the head, neck and chest.
You use it to draw air deep into your lungs. Here, oxygen passes into the blood
and then spreads all around your body.
The upper airways in the head and neck include the throat and the nasal
chamber.
The lower airways include the trachea in the neck and the tubes called
bronchi and bronchioles, which carry air into the lungs. At the top of the trachea
is the larynx, also called “voice box,” which produce the voice when air passes
through it.
The most important muscles of the respiratory system are the dome-shaped
diaphragm below the lungs and the long muscles between the ribs called
intercostals. The backbone, ribs, and breastbone form a cage around the lungs to
protect it while still allowing the breathing process to occur.
3. Parts of the Respiratory System and Their Functions
1. Nose and Nasal Cavity
The nose is the uppermost part of the
respiratory tract. It forms a hollow passage
that connects the nostrils and the top of the
throat. This passage is called the nasal cavity.
The nose is separated into two nostrils by a
wall of cartilage. The nostrils have small hairs
inside them that catch bits of dust and other
particles floating in the air.
4. The nasal cavity is separated from the
mouth by the palate, which is divided into the
hard, bony palate at the front and the soft
palate at the back.
The lining of the nasal cavity is coated with a
layer of mucus---a thick, sticky fluid that
moistens the air and traps duct, germs, and
other particles. The adenoids are bulges of
tissue that help to trap and remove germs
from air.
5. 2. Throat
The throat connects your mouth and nasal
cavity to your trachea or windpipe, and the
esophagus, which is a tube down to the stomach.
The upper part of the throat is called pharynx, while
the lower part is called the larynx. At the sides of
the throat, there are bulges of special germ-killing
tissue called the tonsils, which like the adenoids,
help to fight infection.
6. The pharynx also acts like a station where the
food tube and the air tube meet. The food being
swallowed is prevented from entering the air tube
by a thin structure called epiglottis. This piece of
cartilage blocks the upper entrance to your
trachea, which means that food slides down into
the esophagus. It is not possible to breathe when
swallowing because the trachea is closed.
7. 3. Larynx and trachea
The larynx is at the top of the trachea. On
men and women, it can be seen as a hard bulge at
the front of the neck called the Adam’s apple.
However, it is more prominent in men than in
women. The larynx allows you to make sounds
that can be range from a quiet whisper to a loud
shout.
The vocal chords are two flap-like ridges or
strips that stick out from the inside of the larynx.
8. The trachea begins just below the larynx and
ends behind the upper part of the breastbone
where it divides to form two tubes. It is made of
elastic tissue and smooth muscles. It also has ring of
elastic cartilage that keep the trachea open when
the neck moves. It is lined with a mucous membrane
and hairlike projections called cilia.
9. 4. Bronchi, bronchioles, and alveoli
The system of branching airways is often compared to an upside-down
tree. The trachea serves as the main trunk of the tree. This divides into main
airway branches---the left bronchus and the right bronchus. These bronchi split
over and over again. They first form secondary bronchi. Then, they split to
become smaller and smaller until they eventually become the smallest airways,
known as bronchioles, which serve as the tree’s twigs.
Each bronchiole ends in balloon-like air sacs called alveoli. The alveoli have
thin walls which are surrounded by blood vessels. The bronchi and bronchioles
form the air passage into the lungs. The exchange of oxygen and carbon dioxide
takes in the alveoli. There are about 300 million alveoli in the lungs. These alveoli
increase the surface area of the lungs and allow many blood vessels to collect
oxygen.
11. 5. Lungs
The lungs are the main organ of the
respiratory system. There are two lungs which are
found in the chest on the right and the left side.
The pleurae (sing. Pleura) are the protective
linings that cover the lungs. From front to back,
the lungs fill the rib cage but are separated by the
heart, which lies in between them. The right lung
is slightly larger and heavier than the left.
The main function of the lungs is to help
oxygen from the air you breathe enter the cells in
the blood.
12. Breathing is the taking of air into and out of the lungs. You inhale when you take in
air, and exhale when you force it out.
Breathing involves the action of the rib muscles and the diaphragm. The diaphragm
is the sheet of muscles that separate the chest cavity from the abdominal cavity of your
body. When these muscles contract or relax, they make the size of the chest cavity
change.
You inhale air through your nostrils as you breathe in, which then passes through
the nasal cavity, from where the oxygen-rich air reaches your lungs through the
windpipe. When you inhale, the ribs move up and outwards while the diaphragm
moves down. An exact opposite movement occur during exhalation when the ribs
move down and inwards the diaphragm moves up.
Mechanism of Breathing
13. 1. Do breathing exercises.
2. Exercise regularly.
3. Cover your mouth and nose.
4. Avoid substances that are bad for the health.
Editor's Notes
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