S TEM CELLS By: The Avengers

H ISTORY BEHIND S TEM CELLS First Treatment: 2010, in Atlanta First Patient: patient suffering with paralysis after a spine injury was on trial for using stem cells from a vitro embryo. First Treatment: the stem cells were injected directly into the site of the spinal injury. In 2011, study was lunched to treat color blindness

P ROPERTIES OF S TEM C ELLS Stem cells are able to produce cells that are used in the body. Three properties of stem cells: 1. Capable of dividing and renewing themselves continually. 2. Are unspecialized, 3. Can give rise to specialized cells. Ex: it can’t carry Oxygen like a red blood cell, but unspecialized cells can make specialized cells like red blood cells.

D IFFERENTIATION The cell goes through several stages, becoming more specialized at every stage. Scientists are beginning to understand, the signals inside and outside cells that trigger each step of the differentiation process.

I NTERNAL AND E XTERNAL S IGNALS FOR C ELL D IFFERENTIATION Internal signals: controlled by cell’s genes, interspersed on long strands of DNA, and carry coded instructions for all cellular structures, and functions. External signals Include: 1. chemicals secreted by other cells 2. physical contact with neighboring cells 3. certain molecules in the microenvironment

PRODUCTION OF NEW CELLS BY S TEM CELLS

B EST S TEM CELLS ! Embryonic stem cells: Totipotent, can give rise to any different cell types. Ex, cell types ranging from muscle and nerve cells to simple skin cells and liver cells. Adult stem cells: multipotent or pluripotent, have a limit to what they kind of cells they can divide into. Ex, Hematopoietic stem cells found in red bone morrow and umbilical cord blood. Can only give rise to blood cells, therefore undifferentiated.

W HY A RE EMBRYONIC AND A DULT STEM CELLS D IFFERENT ? In the embryo, no genes on the DNA have been turned on or off therefore, these cells can be altered in anyway to fit a specific need. In Adult: the genes have already been altered in the DNA, therefore diversity of cell is greatly decreased. ( cell has been differentiated).

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