cells alive 7- stem cells Flashcards
what are stem cells?
a cell that has the ability to continuously divide and differentiate into various other kinds of cells/tissues
what are the 3 types of stem cell?
- totipotent
- pluripotent
- mulitopotent
what are totipotent stem cells?
each cell can develop into a new individual cell
what are pluripotent stem cells?
cells can form any cell type
what are mulitpotent stem cells?
cells differentiated, but can form a number of other tissues
what are the stages of embryogenesis?
- cleavage: 2 cells
- 8 cell stage: totipotent
- blastocyst: have pluripotent stem cels
- blastocyst inner mass cells
once cells are fully differentiated what are they called and what does this mean?
- unipotent
- they can still replicate (with limits) but they will only give rise to cells with identical phenotypic characteristics
what is meant by stem cell niche?
- area of the tissue in which the stem cells reside in a quiescent (dormant) status, they arent doing anything
- cell to cell and cell to ECM interaction influence the fate of these stem cells
- These stem cells will get signals when they stem cells are needed
- maintenance of quiescence
- self renewal
- differentiation
name the locations of stem cell niches
- bone marrow
- skin
- central nervous system
- gut
- muscle
what is differentiation?
process by a cell become specialised
where are stem cell niches found in bone marrow?
near osteoblastic lining
where are stem cell niches found in skin?
in bulge of hair follicle
what do we know about stem cell niches in central nervous system?
in the brain, dont really know much about them/where they are or what they do
what are stem cells called in the muscle? what do we know about them?
- satellite cells
- not very prone to differentiating
what do we know about stem cell niches in the gut?
- in epithelium
- found in the crypt
- replaced frequently