Week 03 Flashcards
_____: increased number of fibres in series related with increased in velocity of contraction (additive)
Series
_____: increased number of fibres in parallel associated with increase in force production
Parallel
_______: allows for more packing of sarcomeres in parallel (most muscles)
Pennation angle
When gene expression is altered in the cell, it results in an increase or decrease in the amount of…?
Specific proteins
______ is defined as the capacity for adaptive change in the cell
plasticity
Approx ___ % of skeletal muscle is composed of proteins (balance being water, salts, other organic molecules)
20%
Myoplasticity is predicted on the ability of genetic machine to change either _____ or ____ of protein it expresses for a desired outcome
quantity or variant
Hyperplasia refers to…?
an increased number of muscle cells
Is there evidence of hyperplasia in humans from training?
Little evidence, more in animals
hypertrophy refers to….?
making the fibre larger
Hypertrophy vs hyperplasia??
Hyperplasia = fibre same size, but fibre number increases Hypertrophy = individual fibre larger
Cell prescription refers to…
DNA to mRNA
Cell translated refers to…
mRNA to protein
Cell degradation refers to…
protein to amino acids
The level of any protein in a muscle is proportional to …?
The rate of synthesis relative to the rate of degradation
The goal for hypertrophy is for….?
For synthesis to exceed degradation and lead to protein accretion within the muscle over time
What is the function of protein kinase?
It modifies other proteins via phosphorylation
Myostatin regulates _______
hypertrophy
Myostatin deficiency or knockout can lead to increase ….?
increase muscle mass via not negatively regulating protein synthesis
What are 3 possible candidates for metabolic stress?
- lactate buildup
- a ketoglutarate
- skeletal muscle protein breakdown
Just applying _____ to muscle is enough to cause protein synthesis.
tension
How does the cell infer tension? (2)
- Membrane mechanisms (sarcolemma - phosphatidic acid)
2. Tensor sensors (costameres - connect Z disk to extracellular matrix, & focal adhesion kinase)
HYPERTROPHY: The addition of ___________ and performance of resistance exercise increases protein synthesis
amino acids
HYPERTROPHY: The ability of amino acids and loading to increase protein synthesis is dependent on a permissive level of …???
hormone activity
Acute elevations in anabolic hormones have ____ predictive significance to hypertrophy
No
Rt elicits hypertrophy for what fibre types?
All fibre types
Myostatin function…?
Negatively affects protein turnover and therefore muscle hypertrophy (limits muscle growths if body believes it isn’t needed)
Why do you get such a major DOMS when first exercise or RT after a break?
Sarcoplasmic hypertrophy (fluid in cell that makes it seem larger, not myofibrillar hypertrophy)
Does increase in testosterone have a correlation with increase in muscle fibre/hypertrophy?
No
Does increase in igf-1 have a correlation with increase in muscle fibre/hypertrophy?
No
Does increase in growth hormone have a correlation with increase in muscle fibre/hypertrophy?
Maybe very, very slight
Hypoxic decreases muscle loss by….
decreases blood flow to muscle (esp. post surgery)
