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A number of the SQA Biology courses include the anatomy of the respiratory system. If possible during these topics, we will perform a dissection on a set of animal lungs. This dissection is done as a demonstration.

Katy Tully is a Teacher of Biology and Science. She joined our department in August of this year. Today Katy had organised a lunchtime dissection of the Heart and Lungs. She used the Lungs and Heart of a Lamb today. As I will be performing the same dissection to a number of Standard Grade and Intermediate 1 Pupils tomorrow, I had asked Katy if she wouldn’t mind an extra observer (as always when observing, I was hoping that I could pick-up some new ideas or explanations; and I was not disappointed!).

During a typical Lung Dissection we cover:

Trachea:

Trachea is a common biological term for an airway through which respiratory air transport takes place in organisms

Bronchus:

A bronchus (plural bronchi, adjective bronchial) is a caliber of airway in the respiratory tract that conducts air into the lungs. No gas exchange takes place in this part of the lungs.

Bronchioles:

The bronchioles are the first airway branches that no longer contain cartilage. They are branches of the bronchi, and are smaller than one millimeter in diameter.

Air-Sacs:

Air sac is an anatomical term with several meanings:Pulmonary alveolus, informally known as an air sac, one of innumerable spherical outcroppings of the respiratory bronchioles in the mammalian lung, the primary sites of gas exchange with the blood.

*Quotes from Wikipedia.

But today Katy also mentioned the external membranes of the lungs. This is some thing that I had not covered before. Lungs have a very smooth and slightly slimy outer membrane. This is to combat the potential friction that they may incur during the ongoing process of respiration. When we breathe-in and out, the outer membranes of out lungs may ‘rub’ against our ribcage and/or intercostals muscles. However, this smooth and slimy membrane prevents any potential problems occurring! How wonderful is the human body?!

I would like to thank Katy for her superb dissection today.

Not for the faint hearted, but click the following if you would like a view of the deflated lung.

Click here for a view of the inflated lung.

The images include some annotation.