Cells producing collagen in cirrhosis:

Ans: a (Stellate cell) Ref: Robbins, 7th ed, p. 883In normal liver Type I and Type III collagen are concentrated in the portal tracts and central veins withType IV collagen in the space of disse. In cirrhosis Type I and Type III collagen are deposited in the lobule, creating delicate or broad septal tracts. The major source of this excess collagen is perisinusoidal stellate cells in the space of disse.During cirrhosis they become activated; a process involving:* Robust mitotic activity* Shift from lipocyte phenotype to transitional myofibroblast* Increased synthesis and secretion of extracellular matrixStimuli for stellate cells:* Chronic inflammation - cytokine production * Cytokines produced by activated endogenous cells* Dismption of extracellular matrix* Direct stimulation of stellate cells by toxins