Life Lines by Dr. Dolittle

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Archive for June 2022

Are declines in food availability to blame for the menu change?

Yesterday, we marveled over the recent sightings of two killer whales targeting sharks off the coast of South Africa. The recent uptick in shark hunting has scientists wondering how the loss of great white sharks will impact the ecosystem. But it also has some wondering why the orcas are targeting so many sharks when their diets typically consist of a variety of fish and marine mammals.   Clues may lie […]

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Killer whales scare off sharks

A pair of killer whales, nicknamed ‘Port and Starboard’, has been terrorizing great white sharks. In recent years as many as 8 sharks (possibly more) have succumbed to the pair. Many of the discovered sharks were missing their fatty liver and sometimes their heart. While orca hunting escapades are not particularly newsworthy, the antics of these orcas have attracted the attention of scientists as they are altering the ecosystem. Once […]

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Under pressure: One way our bodies regulate blood pressure

Did you know that blood vessels come fully equipped with the ability to help regulate blood pressure? This is possible because of smooth muscle cells that wrap around blood vessels (see image above). Because they wrap around the inner layers of the blood vessel, when these cells contract, the lumen od the blood vessel becomes narrow and increases blood pressure. When they relax, the blood vessels widen thereby lowering blood […]

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Humans do it, cats do it, dogs do it…why can’t rodents or rabbits do it?

Did you know that rodents and rabbits are not able to vomit? This was certainly news to me. So, I had to find out more… First, let’s talk about the difference between retching and vomiting. During retching (or dry heaves), the diaphragm and abdominal muscles contract, which helps increase pressure within the stomach (and prepare the contents for expulsion). Vomiting also involves contractions of the diaphragm, abdominal as well as […]

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