Which organ stores glycogen in the body?

✅ Correct Answer: C — Liver

The liver is the primary organ responsible for storing glycogen. After a carbohydrate-rich meal, excess glucose in the blood is taken up by the liver and converted into glycogen (a polysaccharide) for storage — this process is called glycogenesis. When blood glucose levels drop (e.g., between meals or during exercise), the liver breaks down glycogen back into glucose and releases it into the bloodstream — this process is called glycogenolysis. The liver can store about 100–120 grams of glycogen. Muscles also store glycogen but only for their own use (not released into blood). Insulin promotes glycogenesis; glucagon promotes glycogenolysis.

❌ Why other options are wrong:

• A. Kidney — The kidneys filter blood and regulate blood pressure, electrolytes, and water balance. They do not store glycogen as an energy reserve. Their main function is filtration and urine formation.

• B. Spleen — The spleen is the largest lymphoid organ. It filters old or damaged red blood cells and is involved in immune responses. It does not store glycogen.

• D. Heart — The heart is a muscular organ that pumps blood. It uses glucose and fatty acids for energy but does NOT store glycogen reserves for the rest of the body.

📝 Important Note: Glycogen storage — Liver: 100-120g (for whole body glucose supply); Muscles: 300-400g (only for muscle use). Insulin = promotes glycogenesis (glucose → glycogen). Glucagon = promotes glycogenolysis (glycogen → glucose). Insulin is secreted by beta cells of islets of Langerhans in pancreas. Liver also performs detoxification, bile production, and protein synthesis. Very frequently asked in SSC CGL.