what does increasing myonucleai do to muscle
increase mynoculeai will lead to increased gene expression, this leads to increase protein levels, increased protein levels means the body can build more myofibrils
where is IGF-1 released from and what does it do to satellite cells
- released locally by myofibers and systemically by the liver
- causes satellite cell activation, proliferation and differentiation
how does systemic enviornment impact satellite cells
capillary activation, growth factors and cytokinase can all activate satellite cells
what does satellite cell regulation mean
this mean satellite cell activation, proliferation and differentiation
where are satellite cells found
they are found between the basal laminate and the sarcolema, this is called the satellite cell niche
how does ECM influence satellite cells
changes in ECM can activate satellite cell activation
what does Myostatin do and what is a potential mechanism
it negativly regulates muscle growth, it inhibits satellite cells proliferation and self renewal
when do we typically see a peak in satellite cell activation
3 days after exercise
what are the 4 satellite cell influences
- ECM
- systemic enviornment
- stromal cells
- Myofiber
in older adults what are the 6 limiting factors that cause less muscle hypertropy
- reduced satellite cells
- thicker ECM (espically around type 2 muscle fibres)
- increased myostatin
- some satellite cells once acitvated might die
- slower and less proliferation
- satellite cells are stem cells and can become another type of cell
what is the basal lamina
thin sheet of muscle tissue in the extra cellular matric
will satellite cells cause an increase in muscle cells
no, they just cause them to hypertrophy
what are 4 things that regulate satellite cell regulation
- IGF-1
- HGF
- IL-6
- Myostatin
What are satellite cells
they are stem cells that are required for muscle repair and regernation, it is debated weather they are needed for hypertrophy (large amount of evidence that satellite cells are required for at least long term muscle hypertrophy)
what is the sarcolemma
it is apart of the myofibre cell membrane, it is a phopholipied bilayer
what is the basal lamina mainly comprised of
collagen 4 and laminin
why is IL-6 released and what does it to satellite cells
- released in response to exercise
- it causes satellite cells proliferation and general functioning
why is HGF released and what does it do to satellite cells
- it is released in response ot damage or stretch
- it causes satellite cells activation and proliferation
what does exercise do to satellite cells
this stimulates satellite cells to get out of its niche
