Small intestine. The small intestine is made up of the duodenum, jejunum, and ileum. Together with the esophagus, large intestine, and the stomach, it forms the gastrointestinal tract. In living humans, the small intestine alone measures about 6 to 7 meters long.After death, this length can increase by up to half.mall intestine. The small intestine is made up of the duodenum, jejunum, and ileum. Together with the esophagus, large intestine, and the stomach, it forms the gastrointestinal tract. In living humans, the small intestine alone measures about 6 to 7 meters long. After death, this length can increase by up to half.
Obsidian: Characteristics and Properties. Obsidian is the result of volcanic lava coming in contact with water. Often the lava pours into a lake or ocean and is cooled quickly. This process produces a glassy texture in the resulting rock.Iron and magnesium give the obsidian a dark green to black color.ften the lava pours into a lake or ocean and is cooled quickly. This process produces a glassy texture in the resulting rock. Iron and magnesium give the obsidian a dark green to black color.
The best obsidian is formed underground near a volcanic vent because those rocks will have limited impurities. Obsidian flows are so slow that often other obsidian flows will occur on top of each other causing a streaked appearance in the obsidian rock.he result is a rock that cooled so fast, crystals did not get a chance to form. Obsidian is a volcanic glass with a smooth and uniform structure. Interesting Obsidian Rock Facts: Different varieties of obsidian rock get their names from their appearance.