Structure and Function of Adipose Tissue
Where is visceral fat located?
-Located around organs -First depot to start filling
Where is adipose deposited?
1. Visceral Fat 2. Subcutaneous fat 3. Intermuscular 4. Intramuscular
What is adipose tissue?
Specialized connective tissue that is approximately 80% lipid (fat)
Where is intramuscular fat located?
-Associated with the perimysim -Located between muscle bundles -known as marbling -Starts to form/fill last in the sequence -Varies between species, breeds
What does energy storage mean for fat tissue function?
-Chief storage site of triglyceride storage -In some animals, adipocytes synthesize triglycerides from glycerol and free fatty acids -Triglycerides are broken down and free fatty acids exported for energy
Brown adipose
-Color from vascular supply & mitochondria -Multiple lipid droplets, with a central nucleus -Function is thermogenesis (heat production) by oxidation of fatty acids, uncoupling proteins -per-cardial, peri-renal,iner-scapu lar
What is the function of adipose tissue?
-Cushion and protection of internal organs -Insulation/heat production _energy storage
Adipose tissue is heavily vascularized
-Extensive collateral circulation -Blood flow regulation is almost as dynamic as muscle
Where is subcutaneous fat?
-Located under the skin -Starts to form/fill after visceral fat
Where is intermuscular adipose tissue located?
-associated with epimysium -Located between muscle groups -known as seam fat -Starts to form and fill approximately the same as subcutaneous fat
White adipose
-single lipid droplet with a peripheral nucleus -lipid storage, synthesis in some species -Long term regulation of food intake
What kind of visceral fat are there?
1. Mersenteric fat- around intestines 2. Caul Fat - over stomach 3. Perirenal fat- around kidneys 4. Leaf fat- thoracic cavity
What are the 3 layers that develop with subcutaneous fat?
1. Outer layer comes first- insulation 2. Middle layer comes next- largest, most active 3. Inner layer- last, hard to see in lean animals
How small is cytoplasm in the cell?
1/40th lipid volume
What cells does adipose tissue contain?
Fibroblasts and adipocytes -adipocytes are 20-40% of the DNA in adipose
What is in the cytoplasm only after refeeding?
Glycogen
What do mature adipocytes have in them?
Large lipid droplets and small amount of cytoplasm
What occurs in the cytoplasm?
Lipogenisis and lipolysis
Where is stored lipid not?
Membrane bound
When fat is filling we talk about it going in an order but each spot is never full
Since it is continuous it will feed into visceral, backfat, seam, and marbling
Adipocytes produce factors which influence whole body metabolism
Some of these factors include: -Leptin-appetite regulation, energy expenditure -Adiponectin -insulin resistance -TNFaphla- immune response
What are the two types of adipose tissue?
White and brown
