The respiratory system is a group of organs that perform some very important tasks in our body.
mitochondrion
+

+
+
In the mitrochondria of every cell in our body, a process called cellular respiration is carried out. In cellular
respiration, (click) glucose, which is carried by the bloodstream (click) reacts with oxygen, also carried by the
bloodstream (click) to produce carbon dioxide, which goes into the bloodstream, (click) water, (click) and energy.
The Respiratory System
gets oxygen
to the
bloodstream
+

removes
carbon
dioxide
from the
bloodstream
removes
some water
from the
bloodstream
+
+
The three main functions of our respiratory system are to (click) get oxygen to the bloodstream, which
carries it to all body cells, (click) remove carbon dioxide from the bloodstream and our body, (click) and
remove some of the excess water from the bloodstream and our body.
The
Respiratory
System
Now we’ll show you the main parts of the respiratory system and briefly explain what each of them
does.
nasal cavity
The air you breathe in with your nose goes into the nasal cavity. Hairs and mucous in the nose trap
some particles, and the air is also warmed and moistened.
nasal cavity
oral cavity
Of course, you can also breathe in air through the mouth or oval cavity.
nasal cavity
pharynx
oral cavity
Air from both the nasal and oral cavities goes into the pharynx, or throat.
nasal cavity
pharynx
oral cavity
glottis
The opening at the top of the windpipe, or trachea is called the glottis
nasal cavity
pharynx
oral cavity
glottis
epiglottis
A flap of tissue called the epiglottis covers the glottis when food is being swallowed. This prevents
food from entering the respiratory tract.
nasal cavity
pharynx
oral cavity
glottis
epiglottis
larynx
The top part of the trachea is called the larynx. The larynx contains the vocal chords.
nasal cavity
pharynx
oral cavity
glottis
larynx
epiglottis
trachea
The trachea is the main tube by which air moves from the pharynx to the lungs. The white rings which
surround the trachea are made of cartilidge, a tough type of tissue that is a bit softer than bone, but harder
than muscle. These rings prevent the trachea from collapsing.
nasal cavity
pharynx
oral cavity
glottis
larynx
epiglottis
trachea
bronchi
The trachea branches into two tubes called bronchi. One bronchus goes to each lung.
nasal cavity
pharynx
oral cavity
glottis
larynx
epiglottis
trachea
bronchi
bronchioles
The bronchi branch into many tubes called bronchioles. As they get further from the bronchi,
bronchioles get smaller and smaller. Bronchioles carry air to every part of each lung.
nasal cavity
pharynx
oral cavity
glottis
larynx
epiglottis
trachea
bronchi
bronchioles
rib cage
The rib cage surrounds the lungs. These ribs protect the lungs and also play a role in breathing, as
we’ll see later.
nasal cavity
pharynx
oral cavity
glottis
larynx
bronchi
epiglottis
trachea
lung
bronchioles
rib cage
The lungs are the organs in which gas exchange takes place. We have a left lung and a right lung.
nasal cavity
pharynx
oral cavity
glottis
larynx
bronchi
epiglottis
trachea
lung
bronchioles
diaphragm
rib cage
A large, parachute-shaped muscle at the bottom of the chest cavity is called the diaphragm. It separates the
chest cavity from the abdominal cavity. The diaphragm plays a very important role in breathing.
Now we’ll take a closer look at ends of the bronchioles. If we take this little blue square…
And enlarge it, we’ll represent it by this diagram.
alveolar
sacs
These are clusters of tiny air sacs, or aveolar sacs.
alveolar
sacs
alveoli
Each tiny sac is called an alveolus. It is hollow inside and has a very thin membrane on the outside. Gas exchange between the
lungs and the blood occurs through this membrane. The plural of alveolus is alveoli. It has been estimated that each lung
contains up to 300 million alveoli. This provides a huge surface area for the gas exchange needed by our body.
alveolar
sacs
bronchiole
Air enters and leaves the alveoli through the bronchioles.
alveoli
alveolar
sacs
capillaries
bronchiole
alveoli
A very dense bed of tiny capillaries surrounds each alveolus. This brings blood into very close
contact with the outer membranes of alveoli, through which oxygen and carbon dioxide diffuse.
alveolar
sacs
capillaries
bronchiole
deoxygenated blood
from the heart
alveoli
The blood vessels coloured blue are carrying deoxygenated blood from the heart. As this blood goes
through the capillary beds, it gradually absorbs oxygen from the alveoli and becomes red.
alveolar
sacs
capillaries
oxygenated blood
to the heart
bronchiole
deoxygenated blood
from the heart
These vessels carry red, or oxygenated blood back to the heart.
alveoli
Acknowledgements for Images Used
"Respiratory system complete en" by LadyofHats The image i did myself as sources i used the books:
Sobotta "atlas der anatomie des menschen" ISBN. 3
541 02828 9 , Churchill livingstone "gray's anatomy"
ISBN. 0 433 01505 8, Interamericana. McGraw-hill
"atlas forografico de anatomia del cuerpo humano"
ISBN. 968 25 1677 3. Also used several online
diagrams like ([1] and [2]) Image renamed from
Image:Respiratory system complete.svg. Licensed
under Public Domain via Wikimedia Commons http://commons.wikimedia.org/wiki/File:Respiratory
_system_complete_en.svg#/media/File:Respiratory_
system_complete_en.svg