THURSDAY, Jan. 31 (HealthDay News) -- What a hoot: Scientists say they've discovered how owls can almost fully rotate their heads without damaging the blood vessels in their necks or cutting off the blood supply to their brains.
Owls have four major bone structure and blood vessel adaptations that prevent injury when they rotate their head. Humans lack these adaptations, which helps explain why people are more vulnerable to neck injuries, according to the Johns Hopkins researchers.
"Until now, brain imaging specialists like me who deal with human injuries caused by trauma to arteries in the head and neck have always been puzzled as to why rapid, twisting head movements did not leave thousands of owls lying dead on the forest floor from stroke," study senior investigator and interventional neuroradiologist Dr. Philippe Gailloud said in a Hopkins news release.
"The carotid and vertebral arteries in the neck of most animals -- including owls and humans -- are very fragile and highly susceptible to even minor tears of the vessel lining," added Gailloud, an associate professor in the radiology department at the Johns Hopkins University School of Medicine.
In people, sudden twists of the head and neck can stretch and tear blood vessel linings and lead to blood clots that can break off and cause a stroke. These types of injuries are common and can occur due to whiplash in car crashes, or even after rollercoaster rides or improper chiropractic manipulations, the researchers explained in the news release.
The Hopkins team used angiography, CT imaging scans and medical illustrations to examine the anatomy of a dozen snowy, barred and great horned owls that died of natural causes. Their findings are noted in the Feb.1 issue of the journal Science.
The scientists found that, in owls, bone structure and the vascular network have adapted to support the animal's top-heavy head. With this anatomical design come
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