Lecture 20 QUIZ

Question 1

T/F: a stable isotope has 1 additional neutron

Answer 1

true

Question 2

T/F: Arterio-venous balance measurements are used to measure the rate of appearance and disappearance of the tracer in the veins and in the arteries

Answer 2

true

Question 3

T/F: to study the effect of blood on muscle protein synthesis we need multiple muscle biopsies

Answer 3

true
one before and one after
done in the vastus lateralis because needs less time to recover than other smaller muscles

Question 4

what are the advantages and disadvantages to substrate-specific tracer vs D2O

Answer 4

D2O:
use it for exercise
free-living environment
easy but less precise, more complex
can be done for many weeks

SST:
nutrition studies
more precise
more control on injested/infused amount
more intense on patient

Question 5

T/F: anabolic resistance is the fact that older adults cannot absorb protein the same way a young individual can

Answer 5

false
not only this, there are more than 1 factor defining anabolic resistance, they cannot absorb protein the same way

Question 6

T/F: muscle atrophy is way much faster compared to muscle hypertrophy and can occur in only 3 days of immobilization

Answer 6

true
after 3 days start to see changes
dec. m. strength and mass (much more in older people)
hypertrophy takes 6-8 weeks

Question 7

T/F: the enrichment pool takes 7 hours to get to the steady state

Answer 7

false
takes 2 hours
need to reach enrichment plateau before taking first m. biopsy

Question 8

what type of contraction creates more DOMS

Answer 8

eccentric because there is more damage. harder for myosin heads to resist movement

Question 9

name 3 tests used to measure recovery

Answer 9

m. strength (best one)
algometer
questionnaire
circumference
ROM (goniometer)
blood test (inflammation)

Question 10

T/F: aerobic exercise could influence the expression of mTORC via the activation of AMPK

Answer 10

true
mTORC Î MPS that leads to Î m. mass
Î AMPK with aerobic exercise = lower expression of mTORC because can’t completely block it

Question 11

why does muscle mass matter

Answer 11

fall prevention
functionnality
bone density
metabolism (most important, prevents diabetes, energy expenditure)
disease
QoL

Question 12

what could improve recovery

Answer 12

sleep
food
hydration
exercise (movement in general), increases blood circulation to area needing recovery

Question 13

T/F: stable isotopes are also used to measure energy expenditure

Answer 13

true
double labelled water method often used for this

Question 14

what does increasing muscle protein synthesis do to muscle mass

Answer 14

increases muscle mass on the long term

Question 15

T/F: stable isotopes could be infused or drank and are not radioactive

Answer 15

true

Question 16

T/F: to study muscle protein synthesis, we absolutely need a muscle biopsy and a stable isotope

Answer 16

true

Question 17

T/F: it takes 6 to 8 weeks to observe a significant increase in muscle mass via an MRI or a DXA scan

Answer 17

true

Question 18

Does MPB increase when we exercise and why?

Answer 18

yes because of:
damage to muscle (MPB)
even if the increase in MPS is bigger than the MBP it still increases it

Question 19

what is needed to activate mTORC1

Answer 19

exercise
insulin
food
Hormones
injecting testosterone

Question 20

why are EAA important

Answer 20

because they are not produced in the body so we need to get it from an external source
ex: leucine

Question 21

T/F: gas chromatography mass spectrometry or GCMS is used to identify a compound such as atoms

Answer 21

true
mainly used by geologists to measure atoms

Question 22

How do we maximize MPS

Answer 22

protein (20-30g/meal)
meal distribution
resistance training

Question 23

Do we need additional protein for aerobic athletes

Answer 23

yes compared to sedentary individuals
1.2g/Kg bodyweight for aerobic individuals
0.8g/Kg bodyweight for sedentary individuals
older adults need more due to anabolic resistance

Question 24

what acute and chronic dietary and non dietary factors affect MPS

Answer 24

Acute:
dietary -> eating protein stimulates MPS
non-dietary-> exercise

Chronic:
dietary-> when you eat properly long term
non-dietary-> stimulate using exercise for multiple days + age/sleep/ hormones/prolonged inactivity
need long-term stimulation (multiple days in a row)

Question 25

T/F: D3 creatine is another stable isotope used to measure total muscle mass

Answer 25

true
used to measure muscle mass in urine

Question 26

is it possible to maximize MPS with a vegan diet

Answer 26

yes
need more food compared to omnivores because the amount of protein getting from the diet is higher

Question 27

why is it important to divide protein intake during the 24h

Answer 27

to maximize MPS
4x20g vs 8x10g
best way is 4x20g with 4 hours between meals
also stimulated with exercise

Question 28

why could losing weight fast be problematic

Answer 28

polluants are released in the body when we loose fat fast
kidneys don’t have time to clean them up so they go to the organs and affect the functions
creates high risk of damaging organs
higher risk of relapsing obesity because of the loss of energy expenditure

Question 29

why MHO are protected form CV disease

Answer 29

cross section image done with MRI
fat distribution is lower

Question 30

does the frequency and amplitude of GH secretion decrease at a similar rate throughout the day in older adults as they age

Answer 30

yes
older adults have similar frequency but the amplitude is lower
frequency still decreases but not to the same extent as amplitude

Question 31

how do we measure frailty

Answer 31

bone density
functional test
questionnaires

Question 32

T/F: humans are the only species on the planet that become obese except domesticated pets

Answer 32

true

Question 33

is walking speed a good indicator of functional capacity in older adults

Answer 33

yes

Question 34

is muscle atrophy typically accompanied by both muscle denervation and mitochondrial dysfunction

Answer 34

yes
not only about MPS, other physiological issues