Transcript respiratorysystem

What’s up with our Lungs and
Respiratory System?
Why do we breathe?
Why we breathe
 Our bodies need oxygen, one of several
gasses in our air, to stay alive
 When we breathe air into our lungs, oxygen
passes through the thin walls of the air
sacs and into our blood
 Our heart pumps the blood and oxygen
around our body
Breathing cont’d
 The oxygen we breathe in mixes with a
sugar called glucose, which we get from
our food
 Oxygen and Glucose combined give us
energy
 Energy produces water and the gas Carbon
Dioxide
Breathing cont’d
 Our body does not need these two things
together and carries them back to our
lungs so we may breathe them out
Our Lungs
Our lungs are one of the largest organs in our
body
 They work with our Respiratory system to take in
fresh air, expel stale air and to help us talk
 Our lungs take up most of the space in our chests
 But they aren’t the same size (Left is a bit smaller,
leaves room for our heart)

Our Lungs
 The right lung has 3 sections or lobes
 The left has 2 lobes
 They are protected by our rib cage
 Beneath our lungs is the diaphragm, dome
shaped muscle that works with lungs to
inhale and exhale air
 From the outside healthy lungs are pink
and squishy
Lungs
 The RIGHT LUNG is divided into three LOBES,
or sections.
 The left lung is divided into two LOBES.
 The PLEURA are the two membranes, that
surround each lobe of the lungs and
separate the lungs from the chest wall.
Lungs
 The DIAPHRAGM is the strong wall of muscle
that separates the chest cavity from the
abdominal cavity. By moving downward, it
creates suction to draw in air and expand
the lungs.
 The smallest subdivisions of the bronchi
are called BRONCHIOLES, at the end of which
are the alveoli (plural of alveolus).
Lungs
 The ALVEOLI are the very small air sacs that
are the destination of air breathed in. The
CAPILLARIES are blood vessels that are
imbedded in the walls of the alveoli. Blood
passes through the capillaries, brought to
them by the PULMONARY ARTERY and taken
away by the PULMONARY VEIN. While in the
capillaries the blood discharges carbon
dioxide into the alveoli and takes up
oxygen from the air in the alveoli.
Ribs and Lungs
 The RIBS are bones supporting and
protecting the chest cavity. They move to a
limited degree, helping the lungs to expand
and contract.
 The trachea divides into the two main
BRONCHI (tubes), one for each lung. These,
in turn, subdivide further into bronchioles.
Pharynx and Epiglottis
 The PHARYNX (throat) collects incoming air
from the nose and passes it downward to
the trachea (windpipe).
 The EPIGLOTTIS is a flap of tissue that
guards the entrance to the trachea, closing
when anything is swallowed that should go
into the esophagus and stomach.
Larynx,Esophagus and Trachea
 The LARYNX (voice box) contains the vocal
cords. It is the place where moving air
being breathed in and out creates voice
sounds.
 The ESOPHAGUS is the passage leading
from the mouth and throat to the stomach.
 The TRACHEA (windpipe) is the passage
leading from the pharynx to the lungs.
Bronchial Tubes
 The bronchial tubes are lined with CILIA
(like very small hairs) that have a wave-like
motion. This motion carries MUCUS (sticky
phlegm or liquid) upward and out into the
throat, where it is either coughed up or
swallowed. The mucus catches and holds
much of the dust, germs, and other
unwanted matter that has invaded the
lungs and thus gets rid of it.
Bronchial Tubes
 At the bottom of our trachea (windpipe)
there are 2 large tubes, Main stem bronchi
 One main stem bronchus (sing.) goes to the
left, the other to the right
 The main stem bronchus branches off into
bronchi (other tubes that get smaller and
smaller, like tree branches)
 The tiniest tubes are called bronchioles
Bronchial Tubes and Aveoli
 About 30,000 bronchioles in each lung
 Each bronchiole is about the thickness of a
hair
 At the end of each bronchiole are teeny tiny
air sacs called aveoli
 About 600 million aveoli in the lungs,
stretched out they’d cover a tennis court
Alveoli
 Each alveolus (sing.) has mesh covering of
small blood vessels (capillaries- so small
cells in blood need to line up single file to
pass through)
When we Inhale
 Diaphragm contracts and flattens out,
moves down so lungs have more room to
get larger as they fill with water
 Rib muscles also lift ribs up and outward to
give lungs more space
 On the way down the windpipe, the tiny
hairs (cilia) move to keep mucus and dirt
out of lungs
Inhaling
 Air then goes through bronchi and
bronchioles (series of branches)
 Air finally reaches 600 million alveoli
 As the millions of alveoli fill up with air, the
lungs get bigger
 The alveoli allow oxygen from the air to
pass into the blood
Inhaling cont’d
 All cells in the body need oxygen every
minute
 Oxygen enters blood in the capillaries and
hitches a ride on red blood cells traveling
through layers of blood vessels to the heart
 The heart then sends all oxygenated blood
out to cells in the body
Exhaling
 The reverse, diaphragm moves up, pushing
air out, rib muscles relax, ribs move in
 Cells have used oxygen, blood carries out
CO2 – Carbon dioxide and other wastes that
must leave the body
 Lungs covered by pleural membranes that
keep junk from getting in
Other Parts of the Respiratory
System
 The SINUSES are hollow spaces in the
bones of the head. Small openings connect
them to the nasal cavity. The functions they
serve are not clearly understood, but
include helping to regulate the
temperature and humidity of air breathed
in, as well as to lighten the bone structure
of the head and to give resonance to the
voice.
Oral Cavity
 Air also enters through the ORAL CAVITY
(mouth), especially in people who have a
mouth-breathing habit or whose nasal
passages may be temporarily obstructed,
as by a cold.
Nasal Cavity
 The NASAL CAVITY (nose) is the preferred
entrance for outside air into the
Respiratory System. The hairs that line the
inside wall are part of the air-cleansing
system.
Adenoids
 The ADENOIDS are overgrown lymph tissue
at the top of the throat. When they interfere
with breathing, they are generally removed.
The lymph system, consisting of nodes
(knots of cells) and connecting vessels,
carries fluid throughout the body. This
system helps resist body infection by
filtering out foreign matter, including
germs, and producing cells (lymphocytes)
to fight them.
Tonsils
 The TONSILS are lymph nodes in the wall of
the pharynx that often become infected.
They are an unimportant part of the germfighting system of the body. When infected,
they are generally removed.
Sources
 www.kidshealth.org, Looking at Your Lungs
 Kittredge, Mary. The Respiratory System.
Philadelphia: Chelsea House Publishers,
2000.
Other Resources
Parker, Steve. Lungs. Brookfield, Connecticut:
Copper Beech Books, 1996.
 Parker, Steve. The Lungs and Respiratory System.
Austin, Texas: Raintree Steck-Vaugn Publishers.
 Stille, Darlene. The Respiratory System. New York,
NY: Children’s Press, 1997.
 Ylvisaker, Anne. Your Lungs. Mankato, Minnesota:
Capstone Press, 2002.
