Physical Activity and SKM Flashcards
what is the largest area to dispose of glucose from?
skeletal muscle
skeletal muscle contraction
what are the main two types of contraction
- isotonic
- isometric
what is the regulartory protein that calcium binds to in smooth muscle?
calmodulin
what is the regulatory protein calcium binds to in skeletal and cardiac muscle?
Troponin
define an isotonic contraction
- same tension
- changes in length of muscle
define an isometric contraction
- length doesn’t change
- tension continues to change
skeletal muscle contraction
what are the 2 types of Isotonic muscle contraction and define them (one phrase for each)
- concentric: muscle shortens under same tension
- eccentric: muscle lengthens under same tension
Skeletal muscle Contractions
why do eccentric contractions cause more damage than concentric contractions
- Eccentric does more damage than concentric because muscle is lengthening, so myosin and actin filaments are moving in the ”opposite” way to normal and are peeling apart
Resistance exercise
what does resistance training activate and what does this do?
- Activates mTOR, which regulates muscle protein synthesis and Hypertrophy
what does endurance exercise activate and what does this do?
- activates PGC-1a
- this increases mitochondrial biogenesis
what is the function of mitochondria?
to generate ATP for cells to use
MPS vs MPB
what happens to Muscle Protein Breakdown during sleep
MPB increases
outline, in 3 steps, how resistance training leads to fibre hypertrophy
- mechanical load/stress is applied to muscle fibre cells.
- this activates mTOR protein
- this causes mTOR to regulate muscle protein synthesis of proteins such as myosin and titin
- this leads to bigger muscle fibres
resistance training
is resistance training catabolic or anabolic on its own?
catabolic
Endurance Exercise
what is mitochondrial biogenesis regulated by?
regulated by PGC-1a
what is the main form of ATP production in endurance excercise
oxidative phosphorylation
endurance exercise
what fibres does endurance exercise convert
type II to type I
Requirements for muscle contraction and adaptation to exercise
why does muscle strength increase before muscle mass increases? (size)
this is because the motor neurones adapt to be able to recruit more muscle fibres for contractions
The Motor Unit
what is the motor unit?
a motor unit is:
- the entire motor neurone
- the neuromuscular junction
- all the muscle fibres innervated by the motor neurone
motor unit recruitment
what is the size principle
as greater force is required, the nervous system will stimulate more motor units, motor units with larger fibres and larger number of fibers to achieve the desired strength of contraction
motor unit recruitment
what 2 ways can force generated by a contracting muscle be increased
- Recruiting additional Motor units
- increase motor unit firing rate
motor unit firing rate
what is fused/complete tetanus
- motor units firing at such a fast rate that there is no period of relaxation for contracting muscle
muscle study
what happened to subjects after 4 weeks of training in the study by D. Vecchino, why and what does this mean in real world scenario?
- after 4 weeks, MU recruitment threshold was decreased
- in the real world, this means that it MUs switched on sooner
Define Hertz
frequency/times per second
