Post Embryonic Development: Metamorphosis, Regeneration, Aging Flashcards
what are the 3 stages that occur after the developmental stages?
- metamorphosis
- regeneration
- aging
define metamorphosis
unrecognizable, subtle changes within an organism
metamorphosis is generally under
hormonal control
during metamorphosis it is primarily
thyroid hormones working to activate or inactivate transcription
during metamorphosis, tissues under the influence of hormones will lead to
- degeneration of some
- differentiation of others
define regeneration
post-embryonic restoration of missing tissues
regeneration requires the presence of
intact and functioning nervous systems
what are the 4 approaches to regeneration
- stem cells
- de-differentiation
- morphallaxis
- compensatory regeneration
explain de-differentiation
taking adult structures back to the stage of undifferentiated cell to become respecified
morphallaxis is the
regeneration of specific tissues due to loss/death of existing tissues
explain compensatory regeneration
the proliferation of differentiated cells which maintain their specific function
blastema is a
de-differentiated cell mass
a cell mass is composed of….
these are essentially components of the
- bone cells
- cartilage cells
- myocytes
- nerve cells
- fibroblasts
mesenchymal stem cells
regeneration of blastema cells depends on the
presence of nerves
with regeneration of blastema cells, there’s also a quantitative requirement such as
the minimum # of nerves needed
what is believed to increase the proliferation of the blastema cells?
released factors from neuron
what is believed to increase the proliferation of the blastema cells?
released factors from neurons
what is also critical to stimulate mitosis within the blastemas?
fibroblast growth factors (Fgf2 & Fgf10)
Fgf2 & Fgf10 are released from the
axonal ends
Fgf2 serves as an…
why?
-angiogenesis factor
- b/c regenerating tissues need to reestablish a blood supply
what has shown to induce regeneration? how do they do this?
- denervated blastemas
- infusing Fgf2 directly into them
without nerve innervation and fibroblasts growth factors what would be seen?
skin cells replaced and the formation of scar tissue
what two quotes describe aging?
- deterioration prevailing over synthesis
- death is a part of life
the Albert Einstein College of Medicine sought out the
longevity genes project
the longevity genes project realized that the
- expression of certain gene groups lead to a longer life span
- shorter stature ppl may have a mutation linked to longer life span
what story explains the relationship between mutated genes leading to a longer life span in shorter ppl?
Sadie Kaplan
what are the 7 anti-aging tools?
- stem cell replacement therapy
- injections of HGH & testosterone
- tissue engineering
- caloric restriction
- reduced cholesterol
- suppression of IGF pathways
- antioxidants
HGH: human growth hormone IGF: insulin like grwoth factor
in some insect and animal models blocking the IGF pathway has placed the animals in a
suspended animation w/ slow aging & deterioration
why are antioxidants a potential anti-aging tool?
they reduce free radicles which cause damage/cell death