Talk:2009 Lecture 1
Cells in the Body
1 x 10^14
100,000,000,000,000 cells (100 trillion)
Cells (neurons) in the Brain
100,000,000,000 (100 billion)
60,000 human cells can fit on the head of a pin
sphere about one quarter of an inch in diameter contains an estimated 1,000,000,000 cells
Cells red blood cells
about 2x10^13 1/5 of body cells
How many generations of cell divisions would be required to produce 100000000000000 cells?
2^x = 100000000000000
x = log 100000000000000 / log 2
x = 46.51
x ~ 47
"starts as a single cell and that cell begins to divide and if the volume of that mass of cancer cells doubles every 45 days, then it would take about 30 doublings for the mass of cancer cells to reach the size of a tumor about one quarter inch in diameter. This is the smallest mass that can be detected by examination, x-ray or scan. A cancerous tumor this size contains an estimated 100,000,000 to 1,000,000,000 cancer cells. It would only take 10 more doublings to reach a size considered fatal. Forty doublings would be 1,000,000,000,000 cells or about one kilogram (2.2 pounds) of cancer."