Science Year 6
Session C
The lungs
Working
scientifically
Resources
needed
Biology Strand: Animals, including humans
Programme of study: Identify and name the main parts of the human circulatory system, and
describe the functions of the heart, blood vessels and blood
Plan scientific enquiries, including recognising and controlling variables where necessary
Take measurements with increasing accuracy and precision
Record results
Large plastic bottle, tubing, bowl, water, balloons, tape measure
Whole class teaching: (links to Sessions 9 & 10, Body Bits Theme, Healthy Me Topic)
Today children are going to look closely at the lungs. The exchange of gases that happens in the lungs is known as
respiration. The act of breathing in and out through our nose (& mouth) replenishes the oxygen and removes the
carbon dioxide from our blood. The blood in the arteries transports the oxygen to all the parts of the body & then the
veins carry the de-oxygenated blood back to the heart. Two exceptions to this are: the pulmonary vein that carries
oxygenated blood from the lungs to the heart so that it can be pumped to the rest of the body, & the pulmonary
artery which carries de-oxygenated blood from the heart to the lungs.
Draw a simple tree on a piece of paper with two main branches from the trunk and leaves on the end of some twigs –
now turn it upside down – this is what our lungs are like. Explain that the lungs are made of lots of tubes, the widest
that extends from the mouth to the lungs is called the trachea (or windpipe) and from this a bronchus (note
interesting plural – two bronchi) goes into each lung. Both the trachea & bronchi are held open by rings of cartilage.
The tubes get smaller and smaller (bronchioles) and end in millions of tiny air sacs (alveoli, singular alveolus)
surrounded by capillaries - see diagram at http://www.mikecurtis.org.uk/ks2_respiratory_system.htm. The capillaries
and air sacs have very thin walls through which the gases can easily pass. Amazing fact: the surface area of the sacs
flattened out would cover a tennis court!
Get children to take a very deep breath & then slowly breathe out, encouraging them to feel their ribs & feel for air
leaving mouth as they do so. When we breathe in using our intercostal muscles to pull our ribs up, i.e. our chest rises
pushing our ribs up and out, and a muscle under our lungs (diaphragm) contracts & becomes flatter, which pulls air
into our lungs (about one fifth of the air is oxygen). When the muscles relax, our chest falls & the diaphragm curves up
again - forcing air out of our lungs through our mouth (getting rid of carbon dioxide)! The amount of air that we
breathe in when we take a deep breath is called our lung capacity. Amazing fact: we breathe over 23,000 times a day
(more if we exercise!). Visit http://inteleducationresources.intel.co.uk/viewdetails_ks3.aspx?id=429 and click on
Breathing link to see diagrams, and then click on Breathing and Respiration link & ask volunteers to drag parts to the
correct place on body – they have to be placed very accurately to get the ‘patient’ breathing successfully again!
Group activities:
Independent:
Measure lung capacity: Children use one of the two suggested methods (see resources) for measuring lung capacity
and record their results.
Independent:
Lungs drag and drop: Children visit http://www.kscience.co.uk/animations/lungs.htm or
http://www.kscience.co.uk/animations/lungs.swf to label a lung diagram.
Independent:
Make thin card lungs: Colour, cut out and make lungs with flaps using thin card (see resources).
Plenary:
Discuss the lung capacity findings. Are the results linked to a person’s size? Do our lungs grow with us as we get older?
Ask children if any of them suffer from asthma – explain that it affects their breathing. Show children the video at
http://kidshealth.org/kid/closet/movies/asthma_movie.html and talk about using inhalers.
I can:
1. Explain that the blood collects oxygen from the lungs and in exchange gets rid of carbon dioxide (respiration).
2. Describe the structure of the lungs.
3. Explain what happens when we breathe in and out.
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