Stephen Hawking: 'There is no heaven; it's a fairy story'. In an exclusive interview with the Guardian, the cosmologist shares his thoughts on death, M-theory, human purpose and our chance existence. , science correspondent. Sunday 15 May 2011 17.00 EDT First published on Sunday 15 May 2011 17.00 EDT.
Both the growth of a tumor and the repair of a scrape on the knee are similar because they involve a mass amount of blood cells in a particular area. A growth of a tumor is a huge mass of cells that form together an cause it. And like the forming tumor, when you get a scrape on your knee blood cells are clumped together forming a large mass of blood also. They are different because there isn't an opening to a tumor allowing blood cells to flow out. When there is a scrape on your knee, there is an opening/cut, allowing blood cells to flow out properly.
Dislocated kneecap: The kneecap slides out of position, causing knee pain and swelling. IT (iliotibial) band syndrome: The iliotibial (IT) band is a piece of tough tissue that runs from your hip down to the outer part of your knee. When you overdo activity, it can become inflamed over time. That causes pain on the outer side of the knee and is common in runners when going downhill. Loose cartilage: Sometimes, a knee injury can break loose cartilage. These pieces can get stuck in the joint, which causes pain and swelling.