Physical Activity and SKM

Question 1

what is the largest area to dispose of glucose from?

Answer 1

skeletal muscle

Question 2

skeletal muscle contraction

what are the main two types of contraction

Answer 2

• isotonic
• isometric

Question 3

what is the regulartory protein that calcium binds to in smooth muscle?

Answer 3

calmodulin

Question 4

what is the regulatory protein calcium binds to in skeletal and cardiac muscle?

Answer 4

Troponin

Question 5

define an isotonic contraction

Answer 5

• same tension
• changes in length of muscle

Question 6

define an isometric contraction

Answer 6

• length doesn’t change
• tension continues to change

Question 7

skeletal muscle contraction

what are the 2 types of Isotonic muscle contraction and define them (one phrase for each)

Answer 7

• concentric: muscle shortens under same tension
• eccentric: muscle lengthens under same tension

Question 8

Skeletal muscle Contractions

why do eccentric contractions cause more damage than concentric contractions

Answer 8

• 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

Question 9

Resistance exercise

what does resistance training activate and what does this do?

Answer 9

• Activates mTOR, which regulates muscle protein synthesis and Hypertrophy

Question 10

what does endurance exercise activate and what does this do?

Answer 10

• activates PGC-1a
• this increases mitochondrial biogenesis

Question 11

what is the function of mitochondria?

Answer 11

to generate ATP for cells to use

Question 12

MPS vs MPB

what happens to Muscle Protein Breakdown during sleep

Answer 12

MPB increases

Question 12

outline, in 3 steps, how resistance training leads to fibre hypertrophy

Answer 12

1. mechanical load/stress is applied to muscle fibre cells.
2. this activates mTOR protein
3. this causes mTOR to regulate muscle protein synthesis of proteins such as myosin and titin
4. this leads to bigger muscle fibres

Question 13

resistance training

is resistance training catabolic or anabolic on its own?

Answer 13

catabolic

Question 14

Endurance Exercise

what is mitochondrial biogenesis regulated by?

Answer 14

regulated by PGC-1a

Question 15

what is the main form of ATP production in endurance excercise

Answer 15

oxidative phosphorylation

Question 16

endurance exercise

what fibres does endurance exercise convert

Answer 16

type II to type I

Question 17

Requirements for muscle contraction and adaptation to exercise

why does muscle strength increase before muscle mass increases? (size)

Answer 17

this is because the motor neurones adapt to be able to recruit more muscle fibres for contractions

Question 18

The Motor Unit

what is the motor unit?

Answer 18

a motor unit is:
- the entire motor neurone
- the neuromuscular junction
- all the muscle fibres innervated by the motor neurone

Question 19

motor unit recruitment

what is the size principle

Answer 19

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

Question 20

motor unit recruitment

what 2 ways can force generated by a contracting muscle be increased

Answer 20

• Recruiting additional Motor units
• increase motor unit firing rate

Question 21

motor unit firing rate

what is fused/complete tetanus

Answer 21

• motor units firing at such a fast rate that there is no period of relaxation for contracting muscle

Question 22

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?

Answer 22

• after 4 weeks, MU recruitment threshold was decreased
• in the real world, this means that it MUs switched on sooner

Question 23

Define Hertz

Answer 23

frequency/times per second