1. RESPIRATORY SYSTEM
SBI3U

2. RESPIRATION:
Organisms obtain oxygen which is necessary for the release of energy from food (i.e. breathing)
Cellular Respiration:
Reactions by which organisms release the chemical energy of food (glucose)
The energy is used to make ATP from ADP and is then available for other processes in the body (ex. muscle action, thermal energy…)
Occurs mostly in the mitochondria

3. STRUCTURES INVOLVED IN RESPIRATION:
Using page 440, label and define the role of the structures:

4. THE RESPIRATORY SYSTEM STRUCTURES:

5. ORDER AND FUNCTION OF STRUCTURES:
Nasal passages: filters, warms and traps dirt
Pharynx: dividing point which continues either into the trachea or esophagus
Epiglottis: covers trachea on swallowing to prevent food from entering the lungs
Larynx: contains vocal cords—the voicebox
Trachea: (windpipe), passes air from pharynx to lung; contains rings of cartilage for support to keep it open
Bronchi (bronchus): pass air from trachea to bronchioles in each lung
Bronchioles: branch off the bronchi, pass air from bronchus to alveoli
Alveoli: contain the pulmonary capillaries and are the sites of gas exchange with the circulatory system

6. OTHER STRUCTURES
Pleural membranes: surrounds the lung and lines the inner wall of the chest cavity
Diaphragm: sheet of muscle that separates the organs of the thoracic/chest cavity from those in the abdominal cavity
Intercostal Muscles: between the ribs and contract during breathing
Lung: enclosed within the thoracic (chest) cavity and protected by the rib cage, thin permeable membrane for diffusion, large surface area for gas exchange

7. HOW DO WE BREATHE? Two main stages:
Inspiration: inhaling – air moves into the lungs
Expiration: exhaling – air is forced out of lungs

8. INSPIRATION/INHALING:
Diaphragm (muscle) contracts  moves downward
Rib muscles contract  rib cage moves up and out
Result:
Volume of chest cavity increases
Lowers air pressure in the chest
Air moves down trachea into lungs filling extra space

9. EXPIRATION/EXHALING:
Diaphragm relaxes  moves upward
Rib cages relaxes  moves inward and down
Result:
Decreases volume
Increases pressure in chest
Air moves out of lungs

10. THE MECHANICS OF BREATHING
INHALATION
Diaphragm and intercostal muscles ____________.
Rib cage pulls _____ and out. Diaphragm flattens out.
Thoracic cavity __________
Pressure in the chest cavity _________ compared to air pressure.
Air rushes ______ lungs.
EXHALATION
Diaphragm and intercostal muscles __________.
Rib cage moves _________ and in. Diaphragm moves back ____.
Thoracic cavity size _______.
Pressure in chest cavity ______ compared to air pressure.
Air rushes ______lungs.
relax
contract
down up up
enlarges
decreases
decreases
increases
into
out

11. OXYGEN TRANSPORT: Red blood cells contain hemoglobin
Hemoglobin contains 4 atoms of iron and each atom binds a molecule of oxygen
Hemoglobin (33 sec)

12. OXYGEN TRANSPORT: AT TISSUES:
Oxygen in lungs diffuses from alveoli to red blood cells in capillaries
Oxygenated blood travels to the heart
Heart pumps blood to tissues
Oxygen diffuses from RBC to tissues
CO2 moves from tissues to hemoglobin in RBC
Oxygen Transport (play for about 2 min only)

13. CARBON DIOXIDE TRANSPORT:
CO2 diffuses from tissues and attaches to hemoglobin on RBC
Deoxygenated blood travels to the heart
Heart pumps blood to the lungs
In the lungs CO2 diffuses from RBC in the capillaries to the alveoli
CO2 is exhaled

14. CONTROLLING BREATHING:
Breathing is controlled by nerve impulses from brain
Brain does not monitor oxygen levels, only CO2 levels
Greater CO2 levels in blood  faster breathing
Brain sends signals to rib muscles and diaphragm to contract faster or slower

15. FACTORS THAT AFFECT BREATHING:
Exercise
Stress
Pain
Fear

16. BREATHING IN EXTREMES:
High altitude: less oxygen in air
Breathing rate increases
Number of red blood cells eventually increases
Mountain climbers carry oxygen tanks
Scuba divers:
Always carry oxygen
Use regulators to compensate for pressure changes at different depths
Use mixture of nitrogen and oxygen for safety and extend dive time
Pure oxygen deadly when breathed at depths below 7m

17. Determining Lung Capacity
Define using pg :
a) total lung capacity
b) tidal volume
c) vital capacity
d) VO2

18. Respiratory Disorders
Complete chart using