Lecture 20 QUIZ Flashcards
T/F: a stable isotope has 1 additional neutron
true
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
true
T/F: to study the effect of blood on muscle protein synthesis we need multiple muscle biopsies
true
one before and one after
done in the vastus lateralis because needs less time to recover than other smaller muscles
what are the advantages and disadvantages to substrate-specific tracer vs D2O
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
T/F: anabolic resistance is the fact that older adults cannot absorb protein the same way a young individual can
false
not only this, there are more than 1 factor defining anabolic resistance, they cannot absorb protein the same way
T/F: muscle atrophy is way much faster compared to muscle hypertrophy and can occur in only 3 days of immobilization
true
after 3 days start to see changes
dec. m. strength and mass (much more in older people)
hypertrophy takes 6-8 weeks
T/F: the enrichment pool takes 7 hours to get to the steady state
false
takes 2 hours
need to reach enrichment plateau before taking first m. biopsy
what type of contraction creates more DOMS
eccentric because there is more damage. harder for myosin heads to resist movement
name 3 tests used to measure recovery
m. strength (best one)
algometer
questionnaire
circumference
ROM (goniometer)
blood test (inflammation)
T/F: aerobic exercise could influence the expression of mTORC via the activation of AMPK
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
why does muscle mass matter
fall prevention
functionnality
bone density
metabolism (most important, prevents diabetes, energy expenditure)
disease
QoL
what could improve recovery
sleep
food
hydration
exercise (movement in general), increases blood circulation to area needing recovery
T/F: stable isotopes are also used to measure energy expenditure
true
double labelled water method often used for this
what does increasing muscle protein synthesis do to muscle mass
increases muscle mass on the long term
T/F: stable isotopes could be infused or drank and are not radioactive
true
T/F: to study muscle protein synthesis, we absolutely need a muscle biopsy and a stable isotope
true
T/F: it takes 6 to 8 weeks to observe a significant increase in muscle mass via an MRI or a DXA scan
true
Does MPB increase when we exercise and why?
yes because of:
damage to muscle (MPB)
even if the increase in MPS is bigger than the MBP it still increases it
what is needed to activate mTORC1
exercise
insulin
food
Hormones
injecting testosterone
why are EAA important
because they are not produced in the body so we need to get it from an external source
ex: leucine
T/F: gas chromatography mass spectrometry or GCMS is used to identify a compound such as atoms
true
mainly used by geologists to measure atoms
How do we maximize MPS
protein (20-30g/meal)
meal distribution
resistance training
Do we need additional protein for aerobic athletes
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
what acute and chronic dietary and non dietary factors affect MPS
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)
T/F: D3 creatine is another stable isotope used to measure total muscle mass
true
used to measure muscle mass in urine
is it possible to maximize MPS with a vegan diet
yes
need more food compared to omnivores because the amount of protein getting from the diet is higher
why is it important to divide protein intake during the 24h
to maximize MPS
4x20g vs 8x10g
best way is 4x20g with 4 hours between meals
also stimulated with exercise
why could losing weight fast be problematic
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
why MHO are protected form CV disease
cross section image done with MRI
fat distribution is lower
does the frequency and amplitude of GH secretion decrease at a similar rate throughout the day in older adults as they age
yes
older adults have similar frequency but the amplitude is lower
frequency still decreases but not to the same extent as amplitude
how do we measure frailty
bone density
functional test
questionnaires
T/F: humans are the only species on the planet that become obese except domesticated pets
true
is walking speed a good indicator of functional capacity in older adults
yes
is muscle atrophy typically accompanied by both muscle denervation and mitochondrial dysfunction
yes
not only about MPS, other physiological issues
