cell differentiation Flashcards
define stem cell
biological cells that can differentiate into other types of cells and can divide to produce more of the same type of stem cells (or other cells)
define totipotent
potential to become any cell in the body or placenta e.g. zygote (fertilised egg)
define pluripotent
potential to become a wide number of cells in the body but NOT all e.g. adult stem cells
define unipotent
reserve population that is used to regenerate cells of one lineage
define differentiation
the process by which cells undergo to transform from a less specialised cell to a more specialised cell in order to grow into their function
what are the three types of cells found in the body?
stem cells
germ cells
somatic cells
what is specification?
cell has a pre-determined fate and will follow it in a neutral environment
can change if put in a non-neutral environment
what is determination?
cannot change its fate even if its in a non-specific environment
define apoptosis
programmed cell death
define necrosis
premature death of cells and tissues
explain the process of apoptosis
membrane blebbing
nuclear collapse
apoptotic body formation
engulfed by white blood cells
explain the process of necrosis
membrane disruption respiratory toxins and hypoxia ATP depletion cell swelling and rupture inflammation
what are the two main pathways of apoptosis
intrinsic - targets mitochondria
extrinsic (TNF induced and Fas pathway)
what do capsases do?
initiate and execute apoptosis
what are the intiator capsases?
2 8 9
what are the executioner capsases?
3 6 7
what external factors can cause necrosis?
extremes in temperature
trauma
snake bite
what internal factors can cause necrosis
immune system
oxidative stress
what are treatments of necrosis?
antioxidants
surgical removal of necrotic tissue
maggot debridement therapy
what are the two methods of stem cell division?
asymmetric - one is a SC and one is differentiated
symmetric - both are either SCs or differentiated
what is senescence?
irreversible cell cycle arrest
what are mesenchymal stem cells?
multipotent adult stem cells
is apoptosis reversible?
no
expression of which enzyme makes stem cells proliferate faster?
telomerase
