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.
Blood supply and cancer. As the tumour gets bigger, the centre of it gets further and further away from the blood vessels in the area where it is growing. So the centre of the tumour gets less and less of the oxygen and the other nutrients all cells need to survive.Like healthy cells, cancer cells cannot live without oxygen and nutrients. So they send out signals, called angiogenic factors, that encourage new blood vessels to grow into the tumour.This is called angiogenesis. Without a blood supply, a tumour can't grow much bigger than a pin head.Once a cancer can stimulate blood vessel growth, it can grow bigger and grow more quickly. It will stimulate the growth of hundreds of new capillaries from the nearby blood vessels to bring it nutrients and oxygen.View a transcript of the video about how cancer gets a blood supply.o the centre of the tumour gets less and less of the oxygen and the other nutrients all cells need to survive. Like healthy cells, cancer cells cannot live without oxygen and nutrients. So they send out signals, called angiogenic factors, that encourage new blood vessels to grow into the tumour.