Stem cells Flashcards
(22 cards)
define stem cells
stem cells are cells that are capable of self-renewal or differentiation into a specialised cell type
what is self renewal?
The ability of a cell to divide to produce more of itself
what is difeerentiation?
is the process by which one cell type turns into another
how many cells does a c.elegan have?
1031 or 959
how many cells approx. does a human have?
1 x 10^10
what are haematopoetic stem cell (HSC) ?
stem cells of the blood
what is life span of blood cell?
days to several months
what are HSCs?
A pool of stem cells that can self-renew and differentiate to replenish the blood system
What is used to treat blood cancers normally?
radiation treatment or chemotherapy
name two blood cancers?
leukaemia and lymphoma
Why would a bone marrow transplant of HSCs be used?
to reconstitute the blood system after its been destroyed
How many HSC can repopulate a mices enture immune system?
one
Give examples of adult stem cells? (stem cells grown in a lab isolated form adult tissues and grown in vitro)
Haematopoetic stem cells, mesechymal stem cells, neural stem cells
what are stem cells isolated from adult tissues called?
multipotent
why can adult stem cells be limited in supply in medicine?
although they self renewal they eventually senesce - after a certain number of cell divisions they get old and stop dividing
where can pluripotent cells be derived from?
adult tissues or from embryonic tissues
name two types of pluripotent stem cells?
embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)
what are ESCs?
- derived from early embryos
- can be grown in dishes indefinitely but exist only transiently in nature
- can differentiate into all of the cell types found in adult organisms
what is pluripotency ?
when a stem cell can differentiate into all of the cell types found in the adult organism
How were embryonic stem cells derived originally from mice ?
the method involved extracting 3.5 day old blastocysts from mice and putting them in a cell culture dish with another cell type
what do ESCs cause if implanted in mice?
teratomas
when does a chimera form?
when two embryos fuse after fertilisation leading to the formation of a single person made up of two distinct genetic entities
