RESPIRATORY SYSTEM
Your respiratory system brings O2 into your body and removes CO2
and H2O. This is very important, because a person could live for days
without food and water but only a matter of minutes without breathing.
BREATH IN, BREATH OUT
The purpose of breathing is to bring O2 to the cells of the body and
remove CO2.
INHALING & EXHALING
Air can enter the body through the mouth and/or the nose. Although
the nose is much healthier to breath through. Your nose warms, mucous
moistens the air and cleans the air as it passes. (cilia & mucous) Thus, the
nose acts like an air filter. Your lungs are not muscles (they are tissues),
thus your respiratory system needs help from the skeletal and muscular
systems. Your muscle called the diaphragm enables you to breath. When
you inhale, your diaphragm contracts and your lungs expand as air enters
your body. (ribs move outward) When you exhale, your diaphragm relaxes
and your lungs contract as air leaves your body.
TAKING A BREATH
When you inhale air enters through your nose or mouth. The place
where your nasal passages and mouth meet is called the pharynx. Then the
air enters your windpipe or trachea which leads to two tubes (the bronchi)
which carry the air to each lung. Rings of cartilage are responsible for
holding your trachea open. The epiglottis is the structure that prevents food
and liquid from entering your lungs.
IN THE LUNGS
As air enters the lungs, through the bronchi, passageways become
smaller and smaller branching into bronchioles. At the ends of these
branches form small grape-like air sacs called alveoli. It is here were gas
exchange takes place.
GAS EXCHANGE
Gas exchange takes place through capillary walls surrounding the air
sacs of the alveoli. Here oxygen enters the bloodstream while carbon
dioxide leaves. The air you breathe in is really a mixture of gases. Oxygen
accounts for 19-21%, while carbon dioxide is only .04%. Your blood can
only carry oxygen and carbon dioxide in large quantities.
SPEECH
The larynx is your voice box which houses your vocal cords. You
produce sounds by passing air through the larynx that causes the vocal cords
to vibrate.
CELLULAR RESPIRATION
Cellular respiration is the process by which a cell releases energy
from food. This occurs in the mitochondria. The two types of cellular
respiration are aerobic and anaerobic respiration.
Aerobic respiration is with oxygen. It is respiration requiring the
help of oxygen to foods such as sugar (glucose) and changing it into energy
and carbon dioxide and water (CO2 and H2O).
The overall reaction for aerobic respiration is:
C6H12O6 + 6O2
 6CO2
+ 6H2O + ATP
(glucose + oxygen  carbon dioxide + water + energy)
**the energy released is stored as ATP, this can be used by the cell to do
work when it is needed.
Anaerobic respiration is without oxygen. It is when the breakdown
occurs without oxygen (O2) to produce energy but it releases either lactic
acid or alcohol.
The overall reaction for anaerobic respiration is:
C6H12O6  CO2
+ alcohol + ATP
(glucose  carbon dioxide + alcohol + ATP)
or
C6H12O6  CO2
+ lactic acid + ATP
(glucose  carbon dioxide + lactic acid + ATP)
SUMMARY
 Mechanical respiration is the process in which the body obtains
oxygen and gets rid of carbon dioxide.
 Cellular respiration is the process by which cells release energy from
food.
 In aerobic respiration, glucose is broken down with the help of carbon
dioxide (O2).
 In anaerobic respiration, glucose is broken down without the help of
oxygen.
 The energy that is produced, stored, and used is ATP.
RESPIRATORY SYSTEM
RELATIONSHIPS between…
SKELETAL
SYSTEM
MUSCULAR
SYSTEM
CIRCULATORY
SYSTEM
 The ribs protect
the lungs.
 The diaphragm is
an involuntary and
voluntary muscle
which helps you
breathe.
 The blood carries
oxygen and carbon
dioxide to the lungs.
The lungs filter the
blood and this
oxygenated blood
returns to the heart.
 Protects the lungs
& other parts from
damage.
 Ribs expand
when you breathe in.
 Protects
 Transports gases
between the cells of
the body & lungs.
 Brings O2 to all
the cells of the body.
 Removes CO2 &
water from the cells.
 Transports gases
Between the cells of
body & lungs.
 Brings O2 to all
the cells of the body.
 Removes CO2
& H2O from the
cells.
The path of oxygen through the respiratory system is:
In through the nose (nasal cavity)/mouth → pharynx → epiglottis →
larynx → trachea → bronchi → bronchioles → alveoli → blood →
alveoli → bronchioles → bronchi → trachea → larynx → epiglottis
→ pharynx → nose (nasal cavity)/mouth