Sharks have skin covered in millions of tiny teeth-like scales that point to the tail. If you rub along a shark towards the tail, it would feel smooth, but if you rub the other way, it would be rough. Sharks' teeth can be 20 times as big as human teeth and they can grow back if they are lost. Fins
Vertebrobasilar insufficiency is a condition characterized by poor blood flow to the posterior (back) portion of the brain, which is fed by two vertebral arteries that join to become the basilar artery. Blockage of these arteries occurs over time through a process called atherosclerosis, or the build-up of plaque.
Journal of Clinical and Diagnostic Research. 2011 August, Vol-5(4): 780-782www.jcdr.net Poonam et al., Tortuous vertebral arteries 781 vertebro-basilar insufficiency. These asymptomatic loops may be corrected by a bypass procedure [1].esult: A total of 31 vertebral arteries (22.1%) were showing the tortuous pathway in 25 cadavers (bilateral in six and unilateral in 19 cadavers single coil tortuosity in 26 and double coil in five vertebral arteries).