health-news

Snakes can optimize vision by controlling blood flow

Washington, Nov. 5 : Snakes are able to control their blood flow to optimize their vision, a new study has revealed.


Kevin van Doorn, PhD, and Professor Jacob Sivak, from the Faculty of Science, found that the coachwhip snake's visual blood flow patterns change depending on what's in its environment.

Van Doorn, from the School of Optometry and Vision Science, said that each species' perception of the world is unique due to differences in sensory systems," said.

Instead of eyelids, snakes have a clear scale called a spectacle. It works like a window, covering and protecting their eyes.

Spectacles are the result of eyelids that fuse together and become transparent during embryonic development.

When van Doorn was examining a different part of the eye, the illumination from his instrument detected something unusual.

Surprisingly, these spectacles contained a network of blood vessels, much like a blind on a window. To see if this feature obscured the snake's vision, van Doorn examined if the pattern of blood flow changed under different conditions.

When the snake was resting, the blood vessels in the spectacle constricted and dilated in a regular cycle. This rhythmic pattern repeated several times over the span of several minutes.

But when researchers presented the snake with stimuli it perceived as threatening, the fight-or-flight response changed the spectacle's blood flow pattern. The blood vessel constricted, reducing blood flow for longer periods than at rest, up to several minutes. The absence of blood cells within the vasculature guarantees the best possible visual capacity in times of greatest need.

Next, the research team examined the blood flow pattern of the snake spectacle when the snake shed its skin. They found a third pattern. During this time, the vessels remained dilated and the blood flow stayed strong and continuous, unlike the cyclical pattern seen during resting.

The study has been published in the Journal of Experimental Biology.

--ANI (Posted on 05-11-2013)

health-news headlines

Ear implant may help regrow auditory nerves: Study

Colon cancer linked to dietary fats

Now, smart pill bottle that help you take your meds on time

Ginseng can help treat and prevent influenza and respiratory virus

Now, 3D-printed plaster cast to heal wound faster

How bariatric surgery can help control diabetes

McDonaldisation of gym culture spreading fast: Study

New drug to treat depression?

Now, the ICU comes home - at a fraction of the cost (Health Feature)

Malnutrition not priority for most parties: CRY

Testosterone levels in womb may impact your health

Bone marrow can cure blood disorders

Quick Links: Goa | Munnar | Pondicherry | Free Yearly Horoscope '2014

Comments

Your e-mail:


Your Full Name:


Type verification image:
verification image, type it in the box

Message:

Back to Top