1. The Respiratory System Part 1 – Structures
Grade 12 Biology
Ms. Marcos

2. Why do we need a respiratory system?
Need O2 in
for cellular respiration
make ATP
Need CO2 out
waste product
food
ATP O2
CO2

3. The basic terms: Breathe In!
Move air in
 Breathing
Take O2 from the air and put it in the blood
 External respiration
Take O2 from the blood and give it to the tissues
 Internal respiration
Use O2 (and food) to make ATP
Cellular respiration
Now get rid of CO2 by doing the opposite and breathe out!

4. What structures can you name?

5. Major parts of the Respiratory System
Nasal passages or mouth
receive the air
Warm / moisten
Hair and cilia
trap dust and debris
 Sensory nerves create a sense of smell

6.  Tonsils help to fight infection
Pharynx
Openings to the nose, mouth and lungs
What problems can happen here?
 Tonsils help to fight infection

7. Larynx Produces sound Vocal chords Enlarged in males
Opening (the glottis) covered by the epiglottis during swallowing
See the difference?

8. Movement of the glottis with different pitches

9. Trachea
Lined with cilia
C-shaped rings of cartilage

10. Trachea  bronchi  bronchioles  alveoli
From large  small
Trachea
Bronchi
Many bronchioles
End in small sacs called alveoli
Spongy
Large surface area
Gas exchange
Trachea  bronchi  bronchioles  alveoli

11. Alveoli Huge amount of surface area Surrounded by blood capillaries
Right: 3 lobes
Left: 2 lobes
Why would there be only 2 lobes on the left side?

12. Gas exchange occurs in alveoli

13. Diaphragm Band of muscle below the lungs
Contracts and relaxes to bring air into / out of the lungs

14. What structures can you name now?