Hypertrophy and Satellite Cells Flashcards
________: muscle growth as _________: muscle loss
hypertrophy
atrophy
what are some signals for anabolism (muscle growth)
- exercise (resistance> endurance)
- feeding
- growth factors and hormones
what are some signals for catabolism (muscle loss)
- disuse atrophy
- starvation
- sarcopenia
- cachexia
- anorexia
adaptations are ________ for the type of exercise
specific
“exercise specificity”
primary adaptation to resistance exercise training is an increase in ________
a muscle’s force producing ability (strength)
primary adaptation to endurance training is __________
metabolic efficiency
increased muscle strength from resistance exercise is due to what two components?
neural and hypertrophy factors
does neural or hypertrophic factors occur first?
neural
early gains are due to _________ while long term gains are due to ________
alterations of neural control of trained muscle
increased muscle size (hypertrophy)
in general muscle strength is ________ related to muscle size
directly
primary muscle response to resistance exercise is muscle _________
hypertrophy
what are 2 contributions to hypertrophy?
myofibrillar and sarcoplasmic hypertrophy
what happens in myofibrillar hypertrophy
- increase in contractile proteins
- increase in number and size of myofibrils
- increase in connective, tendinous and ligamentous tissues
what happens in sarcoplasmic hypertrophy
- increase in enzymes, stored nutrients, cytosol, and mitochondria
T or F: you can lose myofibrillar elements faster than sarcoplasmic
F, you can lose sarcoplasmic adaptations much faster that myofibrillar
T or F: type one skeletal muscle does not hypertrophy
F, it does, just type 2 fibers will show greater hypertrophy effects
increase in muscle size is primarily from?
individual fibers getting larger
larger number of CSA = increase number of __________
myofibrils
when myofibrils reach a critical size they split __________
longitudinally
RPS = RPD: ______ muscle
RPS > RPD: ______ muscle
RPS < RPD: _______ muscle
stable
increase/hypertrophy
decrease/atrophy
resistance exercise will ________ protein synthesis
increase
the larger the stimulus the ______ protein the body will create
more
How does muscle protein increase? (the pathway)
DNA -> transcription -> mRNA -> translation at the ribosomes -> new proteins
T or F: only RNA not DNA content increases during resistance exercise
F: DNA increases too because satellite cells merge with muscle cells
what is the master regulator of protein synthesis?
mTORC1 regulation
what are three types of overload stimuli that signals MTORC
1 - mechanotransduction
2 - signaling pathways
3 - gene regulation
What are some inputs to the MTORC pathway?
growth factors (IGF, insulin)
energy status
O2 level
exercise
AA availability
mTORC1 is _______ in the cytosol. with DEPTOR and PRAS40 are removed it becomes ________ at the lysosome
inactive
active
what are outputs from the MTORC pathway
initiate RNA translation and protein synthesis
inhibit genes for lysosome biogenesis and autophagy
T or F: you can have protein translation in a starved state with growth factors
F: you must be in a fed state WITH growth factors
what are 3 jobs of satellite cells?
- proliferation (make daughter cells)
- self-renewal (make more of itself)
- differentiation (myoblasts)
