Deep breath, kids, and take a butcher's at this

5th September 2014 at 01:00

You can't beat an easy lung dissection to get your students interested - and possibly a little nauseous. But you have to do it well. Here's how my lesson works.

First, visit a local butcher's shop (hopefully there is still one near you) to get your hands on some sheep or pig lungs. Try to get those with an oesophagus and trachea attached.

Before the lesson, set up the lab to look as much like an operating room as possible. Place a table at the centre, cover it with white sheets and illuminate it with stage lighting. If you can get hold of some scrubs, even better - although a lab coat and a stethoscope will do. Arrange stools around the central table.

Start the lesson by bringing pupils' attention to the smooth surface of the lungs. Discuss how this, along with the pleural fluid, helps the lungs to move in relation to the rib cage. Remind the class of the role of the diaphragm contracting beneath the lungs and the intercostal muscles expanding the rib cage. Show where approximately the diaphragm is in relation to your own rib cage - it's much higher than most people imagine. Explain how the air is pushed into the lungs by the surrounding air pressure.

Next, contrast the flexible cilia-lined trachea made of cartilage with the muscle-lined oesophagus. You can remind students of peristalsis by squeezing a Smartie down the oesophagus with your fingers; when it appears at the other end, you might see a few green faces. Discuss the role of cilia in keeping dirt particles out of the lungs - and how smoking can affect their action.

Before cutting the lung itself, inflate it using a blower; cue a couple more green faces. Then cut down the trachea with scissors, branching off into the bronchi, remembering to discuss the role of surface area in the functioning of the alveoli. To show how light the lung is, cut off a piece and float it on some water. Draw a comparison with a piece of meat, which would have sunk.

Finally, cut a cross-section across a whole lung horizontally, showing pupils how it is riddled with cartilage bronchioles. Explain that this is why we don't usually eat lungs.

As a plenary, get students to take part in a "draw the sentence" exercise. They must convert eight simple sentences about the action of the lungs into drawings.

Simon Porter works for international schools group Nord Anglia Education

To download the plan for this lesson, visit www.tesconnect.comMyBestLesson

Tell us about your best lesson

Email jon.severs@tesglobal.com

Subscribe to get access to the content on this page.

If you are already a Tes/ Tes Scotland subscriber please log in with your username or email address to get full access to our back issues, CPD library and membership plus page.

Not a subscriber? Find out more about our subscription offers.
Subscribe now
Existing subscriber?
Enter subscription number

Comments

The guide by your side – ensuring you are always up to date with the latest in education.

Get Tes magazine online and delivered to your door. Stay up to date with the latest research, teacher innovation and insight, plus classroom tips and techniques with a Tes magazine subscription.
With a Tes magazine subscription you get exclusive access to our CPD library. Including our New Teachers’ special for NQTS, Ed Tech, How to Get a Job, Trip Planner, Ed Biz Special and all Tes back issues.

Subscribe now