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.
Arterial insufficiency is decreased blood flow or lack of blood flow through your arteries. Arteries are blood vessels that carry blood away from your heart, out to your tissues and organs. Blood flowing through your arteries carries oxygen to all the cells of your body.rterial insufficiency can affect many areas of your body. The symptoms of arterial insufficiency will depend on the arteries and the areas of the body that are affected. It can result in symptoms of a heart attack, such as chest pain and shortness of breath, when it affects the arteries around the heart.