josh fat Flashcards
(32 cards)
what is adipose tissue
tissue made from mostly mature adipocytes (lipocystes)
what is adipogenesis
Occurs in mid-late gestation. proliferation of adipocyte precursors, this increases adipose numbers.
Adipocyte precursor cells aggregate as fat clusters in fat depots surrounding existing capillary beds.
what is lipogenesis
production of fat
brown adioposie cells are from what precursor?
myogenic lineage - myf5 under influence on BMP 7 and PRDM16
(mixed traits of both white and brown adipose)
describe the key trait of the white adipocyte
one large lipid vaculoe (unilocular)
nucleus is pushed against the wall
small amount of mitochondria
describe the key trait of the brown adipocyte
multiple small lipid vaculoe (multilocular)
nucleus is in the center
large amount of mitochondria
increase of neonatal mass is the result of
hyperplasia of precursor cells and hypertrophy of adipocytes.
what is the functional importance of white adipose tissue
Fat depots include perirenal, omental, cardiac & mesenteric depots, these are intra and intermuscular fat
what is the functional importance of brown adipose tissue
Is richly vascularised with abundant mitochondria which allows for lipid & glucose catabolism
High levels of UCP1 -> enables heat production (non-shivering thermogenesis) this is essential to maintain homeostatic body temp in newborns & animals emerging from hibernation.
describe the development of white adipose tissue
visceral fat depots -> subcutaneous fat depot -> intramuscular fat
the final product is primarily made from
Lipid containing fat cells (adipocytes)
stromal vascular component this is an important reservoir of stem cells for new adipocyte production
how are WAT seperated
by septa of loose connective tissue
Collagen and reticular fibres, capillaries and nerves
what is IUCP1 in relation to BAT
Uncoupeling protein 1 which allows for non shivering thermogenesis
what is beige adipose
same lienage of WAT branched into Brite it has mixed traits
white adioposie cells are from what precursor?
adipoblast lineage under FGF10 influence
describe fats
Fats are a subtype of liquid called triglycerides, fatty acids enter adipocytes and are reassembled into triglycerides.
how is the melting point of fats determined
the double bond have a higher melting point and so to do the longer carbon chain.
single bonds and short chains therefore have a lower melting point
what is an example of the influence of fatty acids on animal nutrition
Concentration of copper in a pig diet, high amount will lead to high growth as it will produce lipids with a higher melting point and the resulting FAs will have softer back fat. (Cu activates enzymes which increases oleic acid concentration compared to stearic acid.
what is an example of the influence of fatty acids on animal age
In pigs linoleic acid increases greatly from 3 days of age. Then this will subtly decrease to produce higher melting point and firmness to the tissue. Pigs fed conventional diet up to 6 months of age have lipids rich in palmitic and palmitoleic acid ( 980 mg/g of total fatty acids)
list 4 common fatty acids (lowest to highest melting point)
myristic acid
palmitic acid
stearic acid
arachidic
why is melting point important?
the fatts with a lower melting point will be metabolised more easily then the higher fats.
what is fat accretion
function of lip accumulation + increased adipocytes size + increased fat cell number.
what two process contribute to postnatal adipose accretion
hypotrophy and hyperplasia
how do adipocyte initiate further fat accretion
When adipocytes reach maximum size they secrete GFs and paracrine agents. This stimulated growth and differentiation of adipocyte stem cells in stromal vascular tissue. The recruitment of new cells results in fat cells total increase.
what are VLDLs
Very low density lipoprotein - produced in the liver and transport lipids to adipocytes
