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SCIENCE FACTS
SCIENCE FACTS
Why does the tail of a
lizard move even after it is cut off from the body ?
The voluntary shedding of an appendage from the body of an animal in response to mechanical and / or visual stimulation is termed “ Autotomy .” An example is lizardtail autonomy . A portion of the spinal cord at the proximal end of the lizard tail is the
control centre for the movement of the shed tail . This small portion of the spinal cord assumes control over the signal transmission to perform the movements of the cut-off tail when the tail is no longer connected to the lizard ’ s brain . Recent discovery reveals that the tail motion is an elaborate repetitive motion , a stock of diverse and extremely intricate arrhythmic movements with an acrobatic flips up to 3 cm in height , and these series of movements would slow down .
This complex outburst activity is achieved through multiple networks of neurons in the tail ' s spinal cord . Two active , independent neural circuits regulate the movements following autonomy . The first has regularly repeated rhythmic signals persisting throughout the duration of tail movements , whereas the alternative is possibly sensitive to the external or internal feedback . However the activation of additional neural pathway is still a mystery . The explanations put forth by scientists were random firing until fatigued ; the pathway is sensitive to environmental input and muscle proprioceptors . Sensors present on the surface of the tail relies on the feedback from the environment and based on the information the tail may jump , pivot or travel in a certain direction as evidenced from electromyography . This wiggling stays active for 30 minutes , even after lizards abandon their tails . This behaviour is essential for the lizard to escape from predators as they focus on the shed tail ' s motion while the lizard stays still or gets away . Sometimes the lizard comes back and eats the dropped tail , which is a rich source of fat so that they could recoup some of the lost energy .
WINSPIRE : Empowering youth | December , 2016