Lecture 31

Question 1

What is sarcopenia?

Answer 1

Age-related muscle wasting

Question 2

What is cachexia?

Answer 2

A component of sarcopenia, but not the same

Question 3

Where does sarcopenia occur most in?

Answer 3

Bedridden, slow walking speed, and those with significant atrophy

Question 4

What are the effects of sarcopenia?

Answer 4

low muscle mass
low muscle strength
low physical performance

Question 5

Who does sarcopenis occur most in?

Answer 5

sarcopenia doesnt discriminate against almost anyone, everyone will develop it regardless of their background

Question 6

What is the effect of age on performance?

Answer 6

Gradual decrease, even in those that train

Question 7

What does sarcopenia look like?

Answer 7

Diminished cross sectional area and infiltrating connective tissue

Question 8

When is the onset of sarcopenia?

Answer 8

~50 years old

Question 9

Which is affected more by sarcopenia, fast or slow muscles?

Answer 9

fast, undergo most atrophy

increases type 1 fibre proportion

Question 10

Name some factors controlling muscle mass as we age

Answer 10

Nutrition
Hormones & genetics
Innervation
Inflammation
Oxidative stress
Blood flow
Exercise
Disease
Protein synthesis & degredation

Question 11

What kind of disease is sarcopenia?

Answer 11

neuromuscular syndrome

Question 12

What is believed to happen in sarcopenia?

Answer 12

Neural supply to fast fibres is lost, resulting in muscle wasting, as well as remodelling many to type 1 fibres

Question 13

What are the possible causes of sarcopenia?

Answer 13

loss of signals from nerves to muscles
or
loss of signals from muscles to nerves

Question 14

What is the effect of age on contracting?

Answer 14

impaired release and reuptake of Ca2+, results in slower contraction

Question 15

What happens in neural connections to muscles with age?

Answer 15

Motor neurons are lost, especially in type 2 fibres
Some neurons can give out branches called sprouts, reinnervating type 2 fibres by a type 1 neuron, converting it to type 1

Question 16

What changes occur in nerves during sarcopenia?

Answer 16

widened nerve end plates
longer nerve terminals
fewer side branches
motor end plates usually undergo constant remodelling

Question 17

Is sarcopenia inevitable?

Answer 17

Yes, it will happen to everyone eventually

Question 18

How can sarcopenia be attenuated?

Answer 18

Strength training, flexibility, balance and aerobic exercise for the elderly to increase their strength and increase hypertrophy
Suggests adaptive capacity remains
Neither reverses sarcopenia damage nor stops it however

Question 19

Does sarcopenia attenuation reverse damage?

Answer 19

No, has only therapeutic effect

Question 20

What is the effect of aging on hormones?

Answer 20

Many growth hormone levels decrease, reducing capacity to repair damaged cells

Question 21

Does growth hormone administration reduce sarcopenia?

Answer 21

No, mostly because they are not coupled with exercise training, little effect on its own

Question 22

What is the best intervention for sarcopenia?

Answer 22

Reducing the disease burden by increasing strength and physical function over increasing lean mass. They dont need mammoth muscles, just normal adult sized so they can rely on themselves