Breath Out!
L/O ;- To know and understand the difference between inhaled and exhaled air
Breathing• Movements of the ribs, rib muscles and diaphragm allow air
into and out of the lungs: this is called breathing or ventilation
• When we breathe in, we inhale• When we breathe out, we exhale
• Air passes between the lungs and the outside of the body through the trachea
• The trachea divides into two bronchi, with one bronchus for each lung
• Each bronchus divides further in the lungs into smaller tubes called bronchioles
• At the end of each bronchiole, there is a group of tiny air sacs called alveoli
Inhalation (breathing in)
Exhalation (breathing out)
• Get 1 boiling tube, and fill it 1/3 of the way up with limewater• Using a delivery tube, exhale down the tube into this
limewater (limewater goes cloudy in the presence of CO2) • With a cold mirror breathe onto it (you will notice a liquid
condenses on it) - using cobalt chloride paper test to see if this is water (cobalt chloride goes from blue to pink in the presence of water)
What do you think the differences between inhaled and exhaled air would be?
How could you test for these differences?
Differences Inhaled & Exhaled Air
inhaled air
nitrogen (78%)oxygen (21%)carbon dioxide (0.04%)other
exhaled air
nitrogen (78%)oxygen (17%)carbon dioxide (4%)other
Exhaled air contains less O2, but much more CO2
• The reason we exhale less oxygen but much more carbon dioxide is because of aerobic respiration: -
From digestive system
From breathing
system
useful!useful!Waste product exhaled
Waste product exhaled
carbondioxideglucose oxygen water energy
So how big are you lungs?
Can you see any patterns? What do you think affects
lung volume?