Lesson 3: Breathing and gas exchange

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 2

Chapter 5 (kerboodle) 

Breathing and respiration

Lesson 3: Breathing and gas exchange (p.69-70)

Discussion of hw

Page 45

Breathing in 

-Intercostal muscles - contract

-Diaphragm muscles -  contract

-Increases volume of thorax

- Pressure thorax decreases

- External air pressure is greater

  air moves inside

Breathing out

-Intercostal muscles - relax

-Diaphragm muscles - relax

-Decrease volume of thorax

- Pressure thorax increases

- Internal pressure is greater
   air forced out

Lung structure

-Trachea 

-Bronchus

-Bronchioles

-Alveoli

Gas exchange

-Oxygen diffuses into the water lining

  It diffuses through to the blood

-Carbon doixide diffuses into the lungs

-Blood transports oxygen and 

  carbon dioxide

Lung volume

Adult -> 5 liters of air (deepest breath)

At rest -> 0.5 liter is used

During excersize -> 3 extra liters can be taken in

Tidal volume = volume you breath out while you are resting

Vital capacity = the most air you can breath out

Breathing and excersize

HW for next lesson 

-3 Worksheets on classroom