The Nutritional System

AbstractThe white and brown adipose tissues are organized to form a true organ. They have a different anatomy and perform different functions, but they collaborate thanks to their ability to convert mutually and reversibly following physiological stimuli. This implies a new fundamental property for mature cells, which would be able to reversibly reprogram their genome under physiological conditions. The subcutaneous mammary gland provides another example of their plasticity. Here fat cells are reversibly transformed into glands during pregnancy and breastfeeding. The obese adipose organ is inflamed because hypertrophic fat cells, typical of this condition, die and their cellular residues must be reabsorbed by macrophages. The molecules produced by these cells during their reabsorption work interfere with the insulin receptor, and this induces insulin resistance, which ultimately causes type 2 diabetes. The adipose organ collaborates with those of digestion. Both produce hormones that can influence the nutritional behavior of individuals. They produce molecules that mutually influence functional activities including thermogenesis, which contributes to the interruption of the meal. The nutrients are absorbed by the intestine, stored in the adipose organ, and distributed by them to the whole body between meals. Distribution includes offspring during breastfeeding. The system as a whole is therefore called the nutritional system