The Respiratory System
A GROUP OF DUCTS THAT ARE CAPABLE OF
FILTERING AIR FROM THE ENVIRONMENT
BEFORE ENTERING THE PULMONARY
SYSTEM
Respiratory Tracts
 Upper Respiratory Tract: nose, pharynx and larynx
 Lower Respiratory Tract: trachea, bronchial tree and
lungs
Respiratory Mucosa
 Specialized membrane that lines the air distribution
tubes in the respiratory tree
 Over 125 mL of mucous produced each day
 Mucus serves as an air purification mechanism by
trapping inspired irritants such as dust and pollen
 Cilia on mucosal cells beat in only 1 direction,
moving mucous upward to pharynx for removal.
The Nose
 Functions
Warms and moistens inhaled air
 Contains smell sense organs

 Structure
Nasal septum separates into two cavities
 Lined with mucus membrane
 Sinuses drain into nose

Warming Function of Nasal
Passageways Lab
A PARTNER, COMPUTER BASED LAB
Pharynx (throat)
 Functions
Passageway for food and liquids
 Air distribution

Larynx
 Functions:
Air distribution
 Voice production

 Structure
Thyroid cartilage: makes up Adam's apple
 Epiglottis: partially covers opening to larynx

Trachea
 Structure:
Tube approx. 11 cm long
 Lined with mucous
 C-shaped rings of cartilage hold the trachea open

 Functions:

Passageway for air to move to and from the lungs
*Blockage of the trachea results in 4000 deaths per year
in the United States
Bronchi, Bronchioles and Alveoli
 Function:
Bronchi and Bronchioles: air distribution
 Alveoli: exchange of gases between air and blood

 Structure:
Trachea branches into the right and left bronchi
 Each bronchus branches into smaller and smaller tubes eventually
leading to the bronchioles.
 Bronchioles end in clusters of microscopic alveolar sacs.
 The walls of the alveolar sacs are made up of alveoli

Respiration
THE MECHANICS OF BREATHING
http://www.youtube.com/watch?v=SwYEFu-GKP4&feature=related
The Respiration Reaction
Combustion:
the burning of an organic fuel (food)
in the presence of oxygen (from breathing)
to produce energy (ATP)
C6H12O6 + 602  6CO2 + 6H2O + Energy
Mechanics of Breathing or Pulmonary
Ventilation
 Inspiration: movement of air into lungs
Diaphragm flattens
 External intercostals contract elevating the ribs and increasing
length of thoracic cavity
 Increase in volume (size) causes a decrease in pressure and air
enters the lungs.

 Expiration: movement of air out of lungs
Thorax returns to resting size
 Elastic recoil of lung tissue aids this process
 This process can be forceful

Gas Exchange in the Lungs (External Respiration)
 Carbamino hemoglobin
breaks down into CO2 and
hemoglobin
 CO2 moves out of lung
capillary blood into alveolar
air and our of the body
 O2 moves from alveolar air
into lung capillaries
 Hemoglobin combines with
O2 producing oxyhemoglobin
http://youtube.com/watch?v=bwXvqSqAgKc
Gas Exchange in Tissues
 Oxyhemoglobin breaks down into O2 and
hemoglobin
 O2 moves our of tissue capillary blood and into
tissue cells
 CO2 moves from tissue cells into tissue capillary
blood
 Hemoglobin combines with Co2 forming carbamino
hemoglobin
Gas Exchange Diagram
Air Volumes
 Tidal Volume: amount normally breathed in or out




with each breat
Vital Capacity: largest amount of air that one can
breathe out in one expiration
Expiratory Reserve Volume: amount of air that can
be forcibly exhaled after expiring the tidal volume
Inspiratory Reserve Volume: amount of air that can
be forcibly inhaled after a normal inspiration
Residual Volume: air that remains in te lungs after
the most forceful expiration
Lung Volumes and Capacities
Lab
A CLASS DEMONSTRATION
Why Do I Yawn?
When you are sleepy or drowsy the lungs do not take
enough oxygen from the air.
This causes a shortage of oxygen in our bodies.
The brain senses this shortage of oxygen and sends a
message that causes you to take a deep long breath--a YAWN.
Why Do I Sneeze?
Sneezing is like a cough in the upper breathing
passages.
It is the body's way of removing an irritant from the
sensitive mucous membranes of the nose.
What Causes Hiccups?
Hiccups are the sudden involuntary movements of the
diaphragm.
There are many causes of hiccups. The diaphragm may
get irritated, you may have eaten to fast, or maybe
some substance in the blood could even have
brought on the hiccups.
Your Voice
http://video.google.com/videoplay?docid=7653546673169306790&q=the+vocal+cords&total=798&start=0&
num=10&so=0&type=search&plindex=0
http://video.google.com/videoplay?docid=4768747540890615043&q=the+vocal+cords&total=798&start=0&num=10&so=0&type=search&plindex=1
http://video.google.com/videoplay?docid=8806032677498551906
The Doctors: What Cigarettes Do To Your Body
http://www.youtube.com/watch?v=SwYEFu-GKP4&feature=related