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.
No, Portugal is not a Mediterranean country. It does, however, have a mediterranean climate, but it is not considered a mediterranean country because the south does not have the Mediterranean Sea as a coast.
The Sea of Marmara is often considered a part of the Mediterranean Sea, whereas the Black Sea is generally not. The man-made Suez Canal in the south-east connects the Mediterranean Sea with the Red Sea. Tides are very limited in the Mediterranean as a result of the narrow connection with the ocean.