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?