RESPIRATORY SYSTEM
Human physiology
BREATHING FOR LIFE
 Your cells need food (digestive system) and oxygen
 Respiration is the process that gets oxygen to the cells and
removes waste gases.
THE RESPIRATORY SYSTEM
 1st step: breathing air into your mouth and/or nose
• Nasal - nose cavity
• Oral – mouth cavity
• Diaphragm – sheet of muscle under lungs
 2nd step: air passes structure called larynx
• Larynx – voice box contains vocal cords
• Vocal cords vibrate to produce sounds for speech
THE RESPIRATORY SYSTEM
 3rd step: trachea
• Trachea a long tube leading to your lungs
• Trachea is also called your windpipe
• Epiglottis – flap of skin that closes over trachea when you swallow (so food
doesn’t get into lungs!
 4th step: bronchi &bronchioles
• Bronchi are 2 small tubes which enter the lungs
• Become smaller tubes within the lungs called bronchioles
 5th step: lungs
• Your lungs are like sponges
• Many small air sacs that fill up when you breath in
• Oxygen passes from air sacs into your blood
THE RESPIRATORY SYSTEM
 Your blood carries the oxygen to all of your cells
 Oxygen combines with food to make energy that you need
 Waste products (carbon dioxide and water vapor) are produced
 Waste products are carried back to you lungs and you breath
them out!
mouth
Bronchioles
Air sacs
EXIT SLIP
1. What path does air take after entering the body?
Air goes down the throat to the larynx, trachea, bronchi and then
lungs
2. How does oxygen pass from your lungs into your
blood?
Through the walls of the air sacs
3. What are the waste products that we breathe out?
Carbon dioxide and water vapor