Biology of Obesity: Adipose Tissue Function Flashcards
(38 cards)
What determines the number of fat cells & their distribution
Genetics
When does they number of fat cells stay set?
In adulthood.
Can increase in number, but once developed stay forever.
Can you reduce they number of fat cells in your body?
No, you can shrink the cells but not decrease the number of them.
define cellulite
Fat deposited beneath the skin
Due to genetic deposition
functions of adipose tissue (7)
- cell membrane (structure/flexibility)
- energy production/energy reserve
- lipoproteins (transport & deliver)
- organ protection
- thermal regulation
- carrier for vitamins (ADEK)
- nerve insulation
where is fat stored
adipocytes, released when needed
how is fat stored inside of adipose
Triglyceride/triacylglycerol
What happens when energy is low
- insulin drops, epinephrine rises
-epiniphrine binds to the adipocyte and causes lipolysis
-increase in energy demand, the fatty acids and glycerol can leave the adipocyte and enter the blood
-uptake and oxidation in tissues (sk. muscle tissue) generate energy to meet increased demand
What happens after eating
-insulin keeps the fatty acids inside the adipocyte
-if eating frequently, and consume foods higher in carbohydrate then insulin levels stay high
what are the 2 types of adipose tissue
- white adipose tissue (WAT)-energy storing
- brown adipose tissue (BAT)- energy burning
amount and distribution of adipose tissue depends on what (3)
age, species, biological sex
characteristics and function of brown adipose tissue (3)
-many mitchocondrial (produce heat thermogenisis)
-more blood vessels (give colour)
-more metabolically active (relative to white)
who tends to have BAT opposed to WAT
infants, slender and younger women.
Lower amount in people with increased BMI & increased BF%
characteristics & function of WAT (4)
-actually yellow
-primary site for energy storage and release of hormones that modulate metabolism and insulin resistance
-provides cushioning & insulation
-subcutaneous and viscreal
characteristics & function of subcutaneous adipose tissue (SCAT) 4
-located just under the skin throughout the body
-represent the majority of our total body fat mass
-main source of energy
-general indication od substrate availibility for physical work. When depot becomes full fat must be stored eslewhere
characteristics & function of viscreal adipose tissue (VAT) 4
-located in and around viscreal organs
-stored fat as a result of SCAT depots being full
-genetics play a role in fat distribution patterns
-fat in this area is pro inflammatory
how does adipose tissue regulate metabolism
secretes hormones that are signals percieved by the brain as important indicators of energy stores (impacts appetite, food intake, nutrient absorption & energy expenditure)
what is caloric intake controlled by
appetite (hypothalamus)
what is calorie use controlled by
metabolic rate (thyroid hormones/ physical activity levels)
where are calories stored
adipose tissue
what is the role of the hypothalamus
directs bodily functions; the brains control centre for energy balance
define hedonic & homeostatic hunger
homeostatic- physical ques of hunger
hedonic- hunger from external ques (social/emotional/environmental/situational)
define appetite, satiety & satiation
appetite- desire for particualr food
satiety- feeling of being full after eating
satiation- feeling satisfied after eating
what happens during homeostatic regulation
-hypothalamus recieves signals from periphery
-input from GI, brain & adipokines
-output via motor neurons to GI, etc.
-this stimulates/inhibits hormone release from various areas of the body