ANAT 261 Lecture Notes - Lecture 3: Stratum Spinosum, Sister Chromatids, Thymidine
Document Summary
Stem cells can either differentiate to become themselves, or they can differentiate and make a cell b (in epithelium, they would differentiate to become the cells of the stratum spinosum). Steady state: number of newly originated cells by the stem cells are equal to the number of dead cells on the surface of the epithelium (turnover of stem cells = sells sloughing off) Turnover time: is the time required to change the whole population of the epithelial cells (30 days) Radiautography: provides a means to study the turnover of epithelial cells and of other cell types (experiment explained below ) Before collecting the tissue, you have to feed the mouse 3h thymidine ( -). The thymidine will now get incorporated in the tissue. The tissue gets run under an em microscope. The radioactivity will give you a black dot and now you know that the cell must have taken up the 3h thymidine.