Top 10: What are the heaviest organs in the human body? Source: BBC Science Focus Just how much of your body mass is made up by your vital organs? Find out what the heaviest organs in the human body are, and what they do, here. 1. Skin Average weight: 4,535g Function: Protects against pathogens; provides insulation; synthesizes vitamin D; regulates temperature; provides sensation 2. Liver Average weight: 1,560g Function: Breaks down toxins; produces hormones, proteins and digestive biochemicals; regulates glycogen storage 3. Brain Average weight: 1,500g Function: Drives executive functions such as reasoning; coordinates responses to changes in environment 4. Lungs Average weight: 1,300g Function: Supplies oxygen to be distributed […]