The Respiratory System

7
8
6
5
1
2
3
4

Muscles
Bronchiole
Air sacs /
Alveoli
Trachea / Wind pipe
Lung
Rib
Bronchus
Diaphragm

Alveoli / Air Sacs
This is where gas exchange happens...
• Oxygen diffuses into the blood
• Carbon dioxide diffuses out

Air Sacs
This is where gas exchange happens.
Oxygen diffuses into the blood.
Carbon dioxide diffuses out .

Gas exchange
• Gas exchange occurs in the alveoli of the lungs
• Oxygen diffuses into the blood
• Carbon dioxide diffuses out blood out
O2
CO2 blood in

Why are alveoli so effective for gas exchange?

Alveoli
Alveoli are good at gas exchange because:
• They have a large surface area
• They have a good blood supply
• Their lining is moist
• They are very thin
This means a lot of diffusion can happen quickly!

Why do veins look blue?
Why is blood red?
Haemoglobin, found in red blood cells, carries oxygen around the body.
Haemoglobin contains iron which looks bright red combined with oxygen.

Nice dissection video http://www.bbc.co.uk/scotland/learning/bitesize/st andard/biology/the_body_in_action/the_need_for_ energy_rev3.shtml

What stops things getting into your lungs?

What stops things getting into your lungs?
Mucus and Cilia http://www.youtube.com/watch?v=miEEluVlemQ

Respiratory System
• Trachea and bronchi are lined with:
– Rings of cartilage for support; prevents tubes closing
– Mucus to trap dirt and germs
– Cilia (tiny hairs) to sweep mucus out of the lungs

Model Lung

Breathing
Breathing is not the same as respiration.
Respiration is a chemical reaction.
Breathing is the process of moving air in and out of the body.

Breathing
When you breathe in what happens to...
• Your ribs?
• Your diaphragm?
• The volume of your lungs?

Breathing
Inhale : take air into lungs
Exhale : remove air from lungs

Lung Measurements
Tidal volume : the volume of air you move in and out of your lungs when breathing normally
Vital capacity : this is the maximum volume of air you can move out of your lungs
Peak flow : this is the maximum rate which you can force air out of your lungs

Tidal volume the maximum volume of air you can move out of your lungs
Vital capacity
Peak flow the maximum rate which you can force air out of your lungs volume of air you move in and out of your lungs when breathing normally

How much air can your lungs hold?

How long can you hold your breath?
The man who can hold his breath for 10 minutes!
http://www.youtube.com/watch?v=9Vcv01Jm-Ow

Tidal Volume
(normal breath)
Vital Capacity
(forced exhale)

3800
200
7cm
19cm

What might a doctor use peak flow to test for?
Peak flow can be used to test for asthma.

What factors might affect lung measurements?
What might cause someone to have a bigger or smaller vital capacity?

Size

Age

Sex

Fitness

Videos and Animations

• http://www.ltscotland.org.uk/glowscience/human
_body/lungs/film_151/index.html

Respiration
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/RPRLC/launch.html
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/CRBLC/launch.html

Alveoli
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/AOALC/launch.html

Mucus
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/MUMLC/launch.html

Respiratory System
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/TRSLC/launch.html

Gas Exchange
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/GEXLC/launch.html

Air
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/GEXLC/launch.html
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/DNXLC/launch.html

Breathing
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningsteps/BRVLC/launch.html
• http://lgfl.skoool.co.uk/content/keystage3/biology
/pc/learningSimulations/BRVSC/launch.html

Alveoli
• http://subscription.echalk.co.uk/Science/biology/ breathing/RespiritorySystemLabelling/Respiratory
Label.html

Respiratory System
• http://subscription.echalk.co.uk/Science/biology/ breathing/RespiritorySystemLabelling/Respiratory
Label.html

Breathing
• http://subscription.echalk.co.uk/Science/biology/ breathing/breathingAni/breathing.html