1,721,334 research outputs found
Pink Adipocytes
No full textAdipocytes are lipid-rich parenchymal cells contained in a very plastic organ, whose composition can undergo striking physiologic changes. In standard conditions the organ contains white and brown adipocytes which play opposite roles: lipid storage to meet metabolic requirements and lipid burning for thermogenesis, respectively. During chronic cold exposure, white adipocytes transdifferentiate to brown, to increase thermogenesis, whereas in conditions of chronic positive energy balance brown adipocytes transdifferentiate to white, to increase energy stores. During pregnancy, lactation, and post-lactation, subcutaneous white adipocytes convert to milk-producing glands formed by lipid-rich elements that can be defined as pink adipocytes. Recent fate-mapping data support the conversion of pink to brown adipocytes and the reversible conversion of brown adipocytes to myoepithelial cells of alveoli
Anatomy and physiology of the nutritional system
No full textThe organisms of mammals are composed of organs cooperating as systems that are organized to perform functions which allow the survival of the individual and maintenance of the species. Thus, to reach the main goals of these functions we need systems that ensure nutrient uptake and distribution, thermogenesis, oxygen uptake and distribution, the discharge of toxic internal by-products, the defense from internal and external pathogens, gamete fertilization, and the fine-tuning of the activity of all the tissues composing the organs. Most of these activities also require interactions with the internal and external environment. The latter function is served by the nervous system and the others by the cardiovascular, respiratory, excretory, immune, reproductive and endocrine systems. Nutrient intake and distribution and thermoregulation are realized by the collaborative work of the adipose and the digestive organs. In this review I will outline data on adipose tissue anatomy and function which have been collected during the past 40 years. They provide a convergent body of evidence toward a new concept regarding the collaborative work between the adipose organ and the organs of the gastrointestinal tract, which constitute a system ensuring nutrient search, intake and distribution to the organism. Furthermore, the same system also seems to enable nutrient distribution to the offspring to ensure not only short-term but also long-term homeostasis
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