As a storage substance, glycogen is actively accumulated in cells …..?

In humans, glycogen is a branched polymer of glucose that is stored primarily in the liver and skeletal muscle, which supplies glucose to the bloodstream during periods of fasting and to muscle cells during muscle contraction. Glycogen has been identified in other tissues such as the brain, heart, kidney, adipose tissue, and red blood cells, but the function of glycogen in these tissues is largely unknown. Glycogen synthesis requires a series of reactions that include the entry of glucose into the cell via transporters, phosphorylation of glucose to glucose 6-phosphate, isomerization to glucose 1-phosphate, and the formation of 5-diphosphate-glucose uridine, which is a direct glucose donor for glycogen.