Adipose Tissue (1.5 questions)
describe white adipocytes
- large cells - shapes include round, oval, or polyhedral - nucleus and cytoplasm displaced by large lipid droplet - *lipid droplet is not membrane bound* - the droplet is lost during tissue preparation - the tissue has a characteristic honeycomb appearance
where is white adipose tissue found?
- forms a layer in the connective tissue under the skin called the hypodermis - internally found around organs, in omentum, and bone marrow - also found in feet, axilla, and orbits
where is brown adipose tissue found?
- in fetal life it is most present, but its presence declines during first decade after birth - in adults, brown fat is localized to areas around the kidney, adrenal glands, aorta, regions of the neck, and in the mediastinum - hibernating animals have lots of brown fat
where can adipocytes be found?
- individually or in small groups, can be found scattered throughout loose connective tissue - adipose tissue, where it is the primary cell type
what are two characteristics of brown adipose tissue?
- it is divided into lobules by connective tissue - it contains lots of mitochondria
what are the variances in white adipose tissue?
- thickness varies in different parts of the body - there is a sexual difference in fat deposition
what are the two types of adipose tissue?
- white adipose tissue (predominant type in adults) - brown adipose tissue (large amounts in fetal life that diminishes throughout life)
what transcription factor plays a critical part in the differentiation of BROWN adipocytes?
PRDM16/PGC-1
what is adipose tissue?
a specialized, highly vascular tissue composed of adipocytes (fat storing cells)
from where do BROWN adipocytes differentiate?
common skeletal myogenic progenitor cells in the dermomyotomes in embryos
what is an adipocyte?
fat storing cells
what is another name for brown adipose tissue?
multilocular (contains numerous fat droplets)
what transcription factor plays a critical part in the differentiation of WHITE adipocytes and the initiation of lipid metabolism?
peroxisome proliferator activated receptor gamma (PPARgamma)/RXR
from where do WHITE adipocytes differentiate?
undifferentiated perivascular mesenchymal cells
what is another name for white adipose tissue?
unilocular (only one fat droplet)