Glycogen is primarily stored in which type of tissues?

Glycogen is primarily stored in muscle and liver tissues because these tissues are central to energy metabolism and regulation in the body. In the liver, glycogen serves as a reserve that can be converted to glucose when blood sugar levels drop, helping to maintain blood glucose homeostasis. The liver can release this glucose into the bloodstream to be utilized by various tissues as needed.

In muscle tissue, glycogen is used as a readily available source of energy during physical activity. When muscles contract, they metabolize glycogen to produce ATP, which is necessary for muscle contraction and performance. This localized storage enables muscles to quickly access energy during intense exertion.

While glycogen is not stored in significant amounts in nervous tissue, epithelial tissue, or connective tissue, these tissues have different functions and energy needs. Nervous tissue, for example, primarily utilizes glucose directly for energy rather than storing it as glycogen.