Liver Anatomy, Function, and Ultrasound Principles for Medical Students Practice Test

Glycogen is the carbohydrate reserve stored by the liver. The liver converts excess glucose into glycogen through glycogenesis, creating a branched polymer that can be rapidly mobilized when blood glucose drops. During fasting, glycogen undergoes glycogenolysis, and in hepatocytes glucose-6-phosphatase converts the product to free glucose that can enter the bloodstream to maintain systemic glucose levels. Free glucose isn’t stored in large amounts in the liver, and simple sugars like fructose and sucrose are absorbed and metabolized rather than stored as a liver reserve. Skeletal muscle also stores glycogen, but it cannot supply glucose to the bloodstream, whereas liver glycogen acts as the body-wide glucose reservoir.