1. SBI 3U WARM UP USING YOUR TEXTBOOK (PAGE 290) LABEL THE DIGESTIVE SYSTEM DIAGRAM

2. RESPIRATORY SYSTEM PRIMARY function: BREATHING (for gas exchange):
uptake oxygen needed by the cells
release carbon dioxide produced by the cells (remove waste, pH balance of blood)
Also used to produce SOUND

3. HUMAN ADAPTATIONS For efficient gas exchange to occur:
Water must be present at the respiratory surface.
Adaptation:
Human lung located within the body cavity which contains a lot of water and air is moistened when it enters lungs.
(Compare this to worm, fish, frog, insect…)

4. HUMAN ADAPTATIONS The respiratory surface must be large Adaptation:
The human lung is made up of many branches to increase its surface area. Spread out on a flat surface it is about 90 m2 (the size of a tennis court!)

5. The Human Respiratory System
Nasal cavity
Path taken by air
Path taken by food

6. The Human Respiratory System
Part
Function
Special Features
Nasal passages
Point of entry
Filter, warm, moisten air
Mucus, hairs, many capillaries, sinus cavities, turbinates
Oral Cavity
Warm and moisten air
Alternate space for gas exchange, no filtration

7. The Human Respiratory System
Nasal Cavity
Path taken by air
Path taken by food
Pharynx
Epiglottis
Esophagus

8. The Human Respiratory System
Part
Function
Special Features
Pharynx
connects nasal and oral cavity to larynx
Cilia in top portion move food towards mouth to be swallowed
Epiglottis
A flap that prevents food from entering the lungs by blocking the glottis (opening of trachea)
Small, flexible

9. The Human Respiratory System
Nasal Cavity
Path taken by air
Path taken by food
Pharynx
Epiglottis
Esophagus
Trachea
Upper
Respiratory
Tract
Larynx

10. The Human Respiratory System
Part
Function
Special Features
Larynx
Contains the vocal cords – for sound, “voice box”
“Adam’s Apple”
two flaps of cartilage, vibrate when air passes through
Trachea
Passage of air into 2 bronchi, “windpipe”
filter particles up to mouth
~12cm long
-Semicircular cartilage rings to prevent collapse -Cilia and mucus

11. The Human Respiratory System
Nasal Cavity
Path taken by air
Path taken by food
Pharynx
Epiglottis
Esophagus
Trachea
Bronchi
Bronchioles
Upper
Respiratory
Tract
Larynx

12. The Human Respiratory System
Part
Function
Special Features
Bronchus
Each carries air into lungs and splits into many bronchioles
Full cartilage rings for support
Bronchiole
Many branches carry air to alveoli
Able to change diameter to regulate air flow
Many branched tubes, Smallest passageways, to increase surface area
Smooth muscle walls
NO cartilage rings

13. The Human Respiratory System
Nasal Cavity
Path taken by air
Path taken by food
Pharynx
Epiglottis
Esophagus
Trachea
Bronchi
Bronchioles
Alveoli
Diaphragm
Upper
Respiratory
Tract
Larynx
Lower
Respiratory
Tract

14. The Human Respiratory System
Part
Function
Special Features
Alveoli (singular: alveolus)
Site of external respiration (gas exchange)
~150 million very thin tiny sacs (large surface area)
Single cell layer thick, surrounded by capillaries
Coated with “surfactant” (a lipoprotein) to prevent sticking
Diaphragm
Increases and decreases volume of chest cavity
Dome shaped, thin, muscular

15. The Human Respiratory System
Part
Function
Special Features
Pleural Membrane
Surrounds lungs and lines chest cavity, reduces friction
Filled with fluid that reduces friction during inhalation