1. The Respiratory System

2. Respiratory System
Whether you know it or not you breath in and out about 15 times each minute.
You move more than 10000L of air in and out of the lungs each day

3. Respiratory System
Provides the oxygen needed by the body and removes the carbon dioxide produced as your body uses energy for growth, repair, and movement.

4. Modelling Asthma Take a straw and try breathing through it.
How is this similar to someone who has asthma?
What does the straw represent in terms of the structures of the respiratory system?

5. Respiration
1) The exchange of O2 and CO2 between the environment and the body
2) The process of cellular respiration that cells use to make ATP
3) Breathing to move air in and out of the body.

6. Respiration 1. Inhaling air containing O2
2. O2 moves (diffuses) from lungs to blood.
3. CO2 moves (diffuses) from blood to lungs
4. Exhaling air containing CO2

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

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

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

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

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

12. The Human Respiratory System
Part
Function
Special Features
Larynx
Contains the vocal cords – for sound
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

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

14. 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
Smallest passageways to increase surface area

15. 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

16. The Human Respiratory System
Part
Function
Special Features
Alveoli
Site of gas exchange (O2 from inhaled air diffuses into capillaries and CO2 in blood diffuses into alveoli)
~150 million very thin tiny sacs (large surface area)
One cell layer thick, surrounded by capillaries
Diaphragm
Increases and decreases volume of chest cavity
Dome shaped, thin, muscular

18. Respiration and Gas Exchange
the gases are exchanged due to differences in CONCENTRATION.
O2 in inhaled air > O2 in blood of capillaries in lungs.
CO2 in inhaled air < CO2 in blood of capillaries in lungs.
So in external respiration,
O2 diffuses from the alveoli to the capillaries and
CO2 diffuses from the capillaries to the alveoli.

19. Mechanics of INSPIRATION (breathing in)
Diaphragm CONTRACTS and FLATTENS (moves downwards)
Rib muscles CONTRACT and move ribcage UPWARDS
Result:
Lung volume:
INCREASED
Pressure inside the lungs:
DECREASED
AIR MOVES IN

20. Mechanics of EXPIRATION (breathing out)
Diaphragm RELAXES and RETURNS to DOME shape
Rib muscles RELAX and move ribcage DOWNWARDS
Result:
Lung volume:
DECREASED
Pressure inside the lungs:
INCREASES
AIR MOVES OUT
*Internal intercostals can pull
ribs in further to force exhalation

21. Lung Capacities
The full capacity of your lungs is not used up under normal conditions - consider yawning, or blowing out a candle, or exercising.
A spirometer is used to measure lung capacities and produces a spirograph

22. Lung Capacities
Tidal Volume: volume of air inhaled and exhaled in a normal breathing movement

23. Lung Capacities
Inspiratory Reserve Volume: the additional volume of air that can be taken in, beyond a regular or tidal inhalation.
Inspiratory Capacity: total volume of air that can be taken in
(TV + IRV)
IRV

24. Lung Capacities
Expiratory Reserve Volume: the additional volume that can be forced out of lungs
Vital Capacity: the total volume of gas that can be moved in or out of the lungs
TV + IRV + ERV = VC
IRV
ERV

25. Lung Capacities
Residual Volume: the amount of gas that remains in the lungs and passageways of the respiratory system even after full exhalation (prevents collapse, no value for gas exchange)