Lecture 15 - Exercise: Muscle Bone And Systemic Changes Flashcards Preview

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Flashcards in Lecture 15 - Exercise: Muscle Bone And Systemic Changes Deck (16):
1

Muscle fatigue

- reversible weakness associated with intense actibity
- eg: run up a mountain

2

Muscle damage

- mild self repairing condition
- muscular dystrophy is characerised by greatly increased stretch induced damage
- eg: run down a mountain

3

Delayed onset msucle soreness

- a form of muscle damage
- reduced force, takes days to recover
- loss of muscle enzymes in the blood
- overstretched sarcomeres

- mainly occurs in contractions involving stretching

4

When are sarcomere unstable

- on the descending aspect of the tension length curve

5

Satellite cell activation and regeneration

- SM contain satellite cells which can divide, form new muscle cells and fuseto form a replacement multinucleate muscle fiber

6

Exercise induced hypertrophy : How

- may involve exercise-induced muscle damage
- involves increased protein synthesis, reduced protein breakdown
- myofibrils thicken
- increased number of sarcomeres
- synthesis of more muscle proteins

7

Exercise and formation of bone

- exercise promotes laying down of new bone more distally

8

Cardiovascular response: why does HR increase

- withdrawal of PNS activity
- increased SNS activity

9

Systemic changes in exercise

- systemic wide vasoconstriction but local vasodilation

10

Muscle mass and VO2

- there is a linear relationship between the total amount of power produced and the amount of oxygen required for taht production of power in one muscle

11

Substrates and ATP generation changes over time

- non oxidative pathway initially and then the glycolysis pathway kicks in
- after 6 hours of exercise, there is a major shift away from glucose oxidation to FA oxidation over time

12

Substrates and ATP generation changes with intensity

- the amount of energy required to support more activity
- optimal fat burning range is around 65%
- if you work harder, more utilisation of muscle glycogen

13

Duchenne muscular dystrophy

- 1 in 3500 male birth
- muscle nromal at birth and then increasing muscle weakness with age
- mild intellectual impairment
- cardiac involvement

14

Why does absence of dystrophin cause muscle damage

- dystrophin is a cytoskeletal protein which connects the contractile proteins to a group of proteins in the cell membrane
- dystrophic muscle is more susceptible to stretch induced muscle damage

15

Exercise as a therapeutic modality

- increased energy expenditure decreases lipid content thereby reducing the processes that inhibits insulin signalling
- increased utilisation of glucose leads to upregulation of processes involved in glucose metabolism
- also net improvement in insulin sensitivity

16

Cardiac output is worload dependent

Predominanlty due to increased HR and to a lesser extent to SV