Here are seven stops on the path of the air, in a mixed order: larynx, alveoli, nasal chamber…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Here are seven stops on the path of the air, in a mixed order: larynx, alveoli, nasal chamber, trachea, terminal bronchioles, pharynx, primary bronchus.
- Put them in the order that a breath of air meets them.
- Which of them are in the exchange part?
- At which vertebra does the trachea divide?
- Which structure keeps food out of the larynx when we swallow?
Need a reminder? The key ideaShow
Different animals use different organs: body surface, moist skin, tracheal tubes, gills or lungs. In humans the air passes through the nostrils, nasal chamber, pharynx, larynx, trachea, bronchi and bronchioles (the conducting part) to the alveoli (the exchange part). The trachea divides at the fifth thoracic vertebra.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) The order is nasal chamber, pharynx, larynx, trachea, primary bronchus, terminal bronchioles, alveoli.
Step 2. (b) Only the alveoli, with their ducts, form the exchange part. The other six belong to the conducting part.
Step 3. (c) The trachea divides at the fifth thoracic vertebra.
Step 4. (d) The epiglottis covers the glottis during swallowing.
Answer: (a) nasal chamber, pharynx, larynx, trachea, primary bronchus, terminal bronchioles, alveoli; (b) alveoli; (c) the fifth thoracic vertebra; (d) the epiglottis.
Watch out. The terminal bronchioles are the last stop of the conducting part. The alveoli come after them.
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