Cell survival

• germ cells stay relatively young forever

• however, babies’ eggs do age, and sperm do age, but not quite as fast as eggs

• bone marrow stem cell can make all the blood cells plus bone marrow stromal cells, but they can’t make heart cells. however, if you tickle a committed skin cell with genes, it can start making blood cells

• you gradually use up all your stem cells, which is why Dr. Baird has 40% cellularity and we have 70%

• the best source of any type of stem cell is still a fetal stem cell because they, although not immortal, are still very young

• normal cells are fully differentiated and they die and are replenished by stem cells

• note that some organs (skin, bone marrow, pancreas) replenish their own cells via division of committed stem cells

• most cancers come from committed stem cells of the organ in question, not from normal, differentiated cells

Category: Medical Subject Notes , Pathology Notes