Stem Cells and Cellular Differentiation Stem Cell Basics: Educational cartoon http://www.youtube.com/watch?v=tPulEAryPO0
Learning Goals • I know the two different types of stem cells. • I have explored the applications of stem cells in the medical research field
Cellular Differentiation • A process by which a less specialized cell develops into a more specialized cell to perform a specific function. • In a multicellular organism, differentiation occurs several times as the zygote develops into cells and tissues. • It is directed by the genetic information inside the cell’s DNA which is passed on from the parents to the offspring.
Stem Cells • Stem cells are found in multicellular organisms that divide through mitosis. They can differentiate into many different types of specialized cell types and self-renew to produce more stem cells. • Two Types of Stem Cells: • Embryonic Stem Cells – These are called pluripotent cells and are able to differentiate into any type of specialized cell. • Tissue Stem Cells – Adults stem cells found in specialized tissues that serve as a repair system for the body, replenishing adult tissue. Example – tissue stem cells in the bone marrow can differentiate into WBC, RBC or platelets.
Cord Blood Cell Banking • After birth, the blood found in the umbilical cord is rich in tissue (or adult) stem cells • These stem cells can differentiate into any of the different types of blood cells. • Parents are often asked if they would like to ‘bank’ (or store) the tissue blood cells after the birth of their newborn baby. • A common use for cord blood stem cells is childhood leukemia
Tissue Stem Cell Transplantation - Leukemia • Cord blood cells and bone marrow stem cells have been used to treat leukemia. • Leukemia is cancer of the bone marrow where stems cells divide out of control and produce non-functioning blood cells. • Chemotherapy is done to remove all of the damaged blood cells and bone marrow transplant occurs from a matched donor. • The healthy bone marrow contains blood stem cells that differentiate into healthy blood cells.
Regeneration and Tissue Engineering • Regeneration is the ability of a tissue to repair itself. • Skin, blood and bone cells are able to regenerate themselves but nerve cells are not able to regenerate completely. • Example: Starfish are able to regenerate their limbs if one is broken off. Salamanders are able to regenerate their tails after it falls off. • Tissue Engineering: Scientists are researching ways to regenerate tissues in the human body that do not normally regenerate themselves. Example? Lab-grown tissue used to repair knee cartilage
Homework • Chapter 3.2, page 79 #2, 4-7