Images Dated 26th September 2003

Blocked Vein Brain Burst Aneurysm Cerebral Blood

An aneurism is a blood filled dilation of a blood vessel and especially an artery resulting from disease of the vessel wall. Brain aneurysms may result from a congenital malformation of a blood vessel or high blood pressure which damages the blood vessels arteriosclerosis or head trauma. They can occur at any age. The onset of bleeding from a ruptured brain aneurysm is usually sudden and without warning. Blocked vein brain burst aneurysm cerebral blood

© Custom Medical Stock Photo

Poison and iodine stickers

© CSA-Printstock

533447465, Backgrounds, Colored Background, Design Element, Healthcare And Med

Weathered limestone

Weathered limestone. Repeated freezing and thawing of water has caused this limestone cliff to be weathered along the bedding planes of the rock. The process, known as freeze-thaw action, occurs when water freezes in the cracks between solid rocks. It causes 9% enlargment of the fissures because water expands as it freezes. Repeated freezing and thawing eventually weakens the rock so much that it splits and a piece falls off. This final stage in the weathering process is called frost-splitting or congelifraction. The weathered rock collects beneath rock faces such as this in scree slopes (not seen). Photographed in the Dachstein Massif in the Austrian Alps

© DIRK WIERSMA/SCIENCE PHOTO LIBRARY