Hepatic stellate cell in the cell body store vitamin A as retinol ester. The function and role of quiescent hepatic stellate cells is unclear. Recent evidence suggests a role as a liver-resident antigen-presenting cell, presenting lipid antigens to and stimulating proliferation of NKT cells. When the liver is damaged, stellate cells can change into an "activated" state. The activated stellate cell is characterized by proliferation, contractility, and chemotaxis. This state of the stellate cell is the main source of extracellular matrix production in liver injury. This attribute makes it a key factor in the pathophysiology of the liver. The amount of stored vitamin
Spermaceti organ Spermaceti organ The spermaceti organ is an organ that commonly appears in the heads of toothed whales of the family Physeteroidea, in particular the sperm whale. This organ contains a waxy liquid called spermaceti and is involved in the generation of sound. In the modern day Great Sperm Whale ("Physeter macrocephalus"), the spermaceti organ is far larger in proportion to the animal’s body than what would be explained by simple allometry, and the evolution of the organ has caused changes in basal skull morphology, which may implicate tradeoffs were made that compromised the functionality of other nearby features. The high