Life Lines by Dr. Dolittle

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Tag Archive for ‘breathing’

Alligator snorkeling

I read an interesting article in Live Science about a unique way a group of American alligators use to survive periods of freezing water, for a few days at least. As the temperature drops, the animals stick their nose out of the water and are thus able to breathe through the ice. During cold months the alligators also reduce their metabolism, a process called brumation, which is different from hibernation […]

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Breathing air

Researchers interested in the evolution of air breathing in bony fishes (Osteicthyes) recently published a fascinating review in the Physiologist. The ability to breathe air made life on land as we know it possible. What is interesting though is that the ability to breathe air actually evolved independently possibly 38-67 times in history. Currently, there are over 400 air-breathing fishes belonging to the Sarcopterygii and Actinopterygii classes. To adapt to life on land, […]

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Importance and dangers of oxygen for air-breathing animals

Although oxygen is essential for air-breathing species and allowed for the evolution of multicellular organisms, it is also a dangerous molecule that can lead to cellular toxicity through the generation of reactive oxygen species (ROS). However, it is important to point out that cellular ROS also play several physiological roles in the body. I just read an interesting review article published in Physiological Reviews that explored natural oxygen delivery and availability […]

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Compromising fish

Here’s something to think about. How do fish optimize gas exchange in their gills to efficiently take up oxygen (favoring large, thin, permeable membranes) while at the same time limiting water and ion movement across the surface? If they reduce surface area, then oxygen transfer will be limited, but ions and water transfer will be optimized. What is a fish to do? A new review article published in Physiology discussed how […]

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What’s up with those lung valves?

The Plenary Lecture at this year’s Comparative Physiology meeting was given by Dr. Colleen Farmer at Trinity College in Dublin who spoke about the diversity of vertebrate respiratory systems including aerodynamic valves that are found in birds and various species of reptiles. These aerodynamic valves allow air to flow in one direction during both inspiration and expiration as opposed to bidirectional flow in mammals. Examination of red-eared sliders (shown above) […]

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