Bellow you will see how to dissect a Pluck and what to look for. Firstly a Pluck is the Lungs, heart and liver of an animal. In this case we are using a sheep pluck. Dissecting a Pluck is a brilliant way for students to observe the how the lungs work and the heart in relation to the lungs.
Prior to starting this dissection, get students to observe a diagram of the lungs.
As you cut through it, ask students to identify differences between the diagram and real lungs.
The first thing you will see when you look at the pluck will be the heart, lungs and liver. Observe the picture to the right.
You can remove the liver for now and put it to one side. Your Pluck should look something like the picture on the left.
Notice the hearts position.
If you flip over the lungs, you will see the heart resting at the back. Observe the image to the right.
Once you have had a look at the organs, and discussed their position in relation to the body, you can begin cutting.
First cut a small bit off the Trachea. You will notice that it dose not collapse.
Small rings of Cartilage hold it open.
If you continue looks you will find an arteries. Notice the difference in texture. It isn't held open by cartilage and has a more muscular feel. Why is this?
Continuing with the trachea, observe the connective tissue surrounding it. Its this tissue which holds the trachea in place.
Continue cutting down the trachea and shown in the image to the left. Cut about ¾ of the way down the trachea.
As you cut down, you will see a small hole in the trachea. This leads to a section of the lung. This is a structure that most students will not have known about, as it isn’t shown in most diagrams.
This whole leads to a small lobe on one of the lungs.
Peer down the trachea and you will see the two bronchioles. They divided into to parts. Supplying each lung with an oxygen and removing Carbon dioxide.
If you have a tube, you can inflate the lungs. Place the tube down one of the bronchioles and blow. This should inflate the lungs. This is shown in the video bellow.
Once you have finished inflating the lungs, you can take a piece off. The moment you touch the lung, you will notice its soft spongy texture. As you place a bit of pressure on it you should be able to feel it crackle, this is the air escaping from the alveoli.
Cut a piece of the lung tissue out and you should be able to see the tubes branching out.
As seen in the picture to the left.
Go back to the top of the bronchiole, use your scissors to cut down one bronchus, following it through the lung.
What you should notice is that the lungs are not one sold shape. The in fact have smaller sections branching off called Lobes.
You will notice that one lung has 3 lobes, while the other has 2 lobes.
This can be observed in the pictures on the left and right, respectively.
Scroll over the images to highlight the lobes
What you should eventually find, is that the bronchioles become smaller and smaller. Branching out through small holes.
Another thing to note is the cartilage continues down a fair distance into the lung.