Week 7- Neural control of energy balance

Question 1

Components of energy expensiture

Answer 1

OBLIGATORY ENERGY EXPENDITURE(BMR)

and

PHYSICAL ACTIVITY

Question 2

Physical activity can be broken down into…

Answer 2

Exercise and NEAT

Question 3

BMR is

Answer 3

the energy expended at rest, it is the energy required to maintain basic cell and organ function. ~70% of total daily expenditure

Question 4

How are BMR, sex and lean mass all related?

Answer 4

BMR is correlated to lean body mass( the higher fat free mas one has the higher their BMR). Becuase men tend ot have higher lean msuckle mass they tend to have higher BMRs than women

Question 5

How does BMR change with age?

Answer 5

once we hit around 40 we start to see changes in BMR(reduce) as our body composition starts to change( we become more predisposed to gaining adipose tissue)

Question 6

What can prevent age related declines in BMR

Answer 6

Exercise to maintain lean body mass

Question 7

is weight change in response to exercise genetically determined?

Answer 7

yes it is, when a tein study was found assessing weight change after bike exercise it found consistent results of weight change between the twins but variability across sets of teisn showing that genetic do play a role.

Question 8

The benefits of exercise on metabolic health

Answer 8

improves lipid profile, reduces fasting glucose and insulin levels, improved insulin sens, reduced haptic fat accum, reduces BP, improved cardiac function.

Question 9

How does weight gain relate to NEAT?

Answer 9

From twin studies, we cna see that the ability to defend against weight gain is genetically predetermined but more than this that NET generally undeprrins this. When we increases NEAT then the response to overfeeding is generally resistant.

Question 10

Uncoupling

Answer 10

occurs in specialised mitochondria where H+ usually going through ARP synthase go through a UCP pore instead to cause a proton leak and produce heat.

This is called uncoupled repisration and is a way that cells dissipate energy diverting it away from cellular energy.

Question 11

Physical challenges that increase adaptive thermogeneis are…

Answer 11

specialised cellualr heat production. occurs in reponse to environmental cues

Question 12

WAT vs BAT characteristics

Answer 12

BAT si enriched in mitochondria, increased vasc supply, lots of small lipid droplets

Question 13

The symp control of BAT

Answer 13

Question 14

how WAT and BAT are derived

Answer 14

Question 15

Rerecruitement of BAT

Answer 15

It was thought that after reaching adolescence that BAT stores reduced( as babies lose need after developing muscle which can shiver) but it has been found that once puberty is reached, with an increase inlean muscle mass, BAT is recruited and redistributed

Question 16

How obesity affects BAT rerecuitment

Answer 16

We see decreased BAT activtiy and rerecuitment but it is unclear is this a cause of consequence of obesity

Question 17

As we age, the prevalence and activation of BAT…

Answer 17

decreases. This is also correlated to increase BMI/adiposity, as this increases BAT activation decreases.

BAT activ is lower in indivs with T2DM or insulin resistance

Question 18

How is BAT associated with insulin sensitvtiy

Answer 18

BAT is important for E expenditure, thus it can help clear gluocse and harmful TAGs and thus is associated with increased sensitivity

Question 19

BAT and varying ambient temperatures

Answer 19

Higher ambient temps see lower BAT

Question 20

is there sexual dimorphism in BAT acitvity?

Answer 20

yes, women have higher BAT activity

Question 21

How is BAT a metabolic sink?

Answer 21

When acitvated there is increased glucose uptake and BAT triglyceride clearance. thus it is insoved in clearance of harmful triglycerides and in improved insulin sensitivity.

Lastly BAT is cardioprotective because of the secretion of BATokines

Question 22

is UCP3 in skeletal muscle as eefective as UCP1?

Answer 22

no it is not, but the higher amounts of skeletal muscle offset this.

Question 23

2 ways that skM can produce heat

Answer 23

UCP3 coupling and via calcium cycling

Question 24

calcium cycling in skM

Answer 24

Question 25

Browning and whitening of fat tissue

Answer 25

Question 26

consequence of complete b-adrenorecptor loss

Answer 26

increased body weight

decreased energy expenditure ( both baseline and in response to cold)

no change in food intake but increase in body weight due to changes in energy expenditure

decreased expression of UCP1( cold intolerance)