Chapter 44 Lecture Enrichment Ideas
Compare the amount of oxygen needed by an animal with little movement versus an animal that moves about a lot, and discuss how the respiratory system is adapted for those needs. In particular, comparisons should be made between invertebrates (such as a hydra or an earthworm) versus flying insects, and between ectothermic vertebrates such as a frog and an endothermic bird that must metabolize ten times more food.
Diagram why a countercurrent exchange mechanism in a fish's gills allows maximal efficiency in absorbing oxygen from the water. This can be related to the same concept seen in the next chapter in the function of the kidney.
Consider why a bird has a complete ventilation method but a mammal does not; consider what different metabolic requirements might have led birds to develop their more efficient mechanism over time.
Query students on the consequence of our wearing our lung on the outside as one large flat gill surface exposed to the air; what would be the consequences for moving it down the hallway, for drying out, for infection, etc.
Before our understanding of the various forms of lung diseases and disorders, the term "consumption" was used for lung ailments now detailed by causative agent in the textbook; this is an excellent opportunity to show how our progress parallels the preciseness of our scientific language.
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