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.
What is Chronic V enous Insufficiency (CVI)? Chronic venous insufficiency (CVI) is a common cause ofleg pain and swelling, and is commonly associated withvaricose veins. It occurs when the valves of the veins donot function properly, and the circulation of blood in theleg veins is impaired.CVI may affect up to 20 percentof adults.hronic venous insufficiency (CVI) is a common cause of. leg pain and swelling, and is commonly associated with. varicose veins. It occurs when the valves of the veins do. not function properly, and the circulation of blood in the. leg veins is impaired.